WO1997018755A1

WO1997018755A1 - Instrument for optical measurement of living body

Info

Publication number: WO1997018755A1
Application number: PCT/JP1996/003365
Authority: WO
Inventors: Yuichi Yamashita; Atsushi Maki; Hideaki Koizumi
Original assignee: Hitachi, Ltd.
Priority date: 1995-11-17
Filing date: 1996-11-15
Publication date: 1997-05-29
Also published as: GB2311854A; GB2311854B; CA2210703A1; GB2311854A9; GB9713004D0; CA2210703C; DE19681107T1; DE19681107B4

Abstract

An instrument for efficient optical measurements of a living body at various points in its wide spatial region to obtain internal information of the living body while eliminating crosstalk. A light source (1) includes a plurality of light modules (2(1) to 2(16)) to emit intensity-modulated beams of light at different frequencies through optical fibers (8-1 to 8-16) so that they can be introduced into the living body (9) at a plurality of points. The beams of light passing through the body are picked up on the surface of the living body (9) and guided to photodetectors (11-1 to 11-25) through optical fibers (10-1 to 10-25). The signals from the photodetector (11-1 to 11-25) are inputted to a lock-in amplifier module (12), where the intensity of the return beam detected by each of the photodetectors and having the same modulation frequency as that of its corresponding input beam is selectively measured. The intensities of beams of light picked up at a plurality of positions are processed by a data processor (16) and the internal information of the living body for a plurality of pickup positions can be obtained without crosstalk.

Description

Description Bio-optical measurement equipment Technical field

The present invention relates to an apparatus for measuring information inside a living body using light.

The development of a technology that can easily measure information inside a living body without harming the living body is expected in fields such as clinical medicine and brain science. For example, when the head is specifically targeted for measurement, there are measurement of brain diseases such as cerebral infarction and intracerebral hemorrhage, and measurement of higher brain functions such as thinking, language and movement. The measurement target is not limited to the head, but also includes preventive diagnosis for heart diseases such as myocardial infarction in the chest and visceral diseases such as kidney and liver damage in the abdomen.

When measuring brain disease or higher brain function with the head as the measurement target, it is necessary to clearly identify the diseased part or functional area. Therefore, it is very important to measure a wide area in the head as image information. An example of this importance is the widespread use of positron emission tomography (PET) and functional nuclear magnetic resonance tomography (fMRI) as image measuring devices in the brain. These devices have the advantage of being able to measure a wide area inside a living body as image information, but have the disadvantage that the devices are large and their handling is complicated. For example, installation of these devices requires a dedicated room, and of course it is not easy to move the devices, and therefore has high restraint on the subject. In addition, the need for dedicated maintenance personnel requires enormous costs to operate these devices.

In view of the above, optical metrology is very promising. The first reason The normal and abnormal organs in the living body, and the activation of the brain for higher brain functions are closely related to oxygen metabolism and blood circulation in the living body. The oxygen metabolism and blood circulation, certain dyes in biological (hemoglobin, Ji Bok chrome aa _3, myoglobin, etc.) corresponds to the concentration of the dye concentration, absorption of light of a wavelength in the infrared region from the visible Because it can be obtained from The second and third reasons that optical measurement technology is effective are that light is easy to handle with an optical fiber and that it does not cause any harm to living organisms when used within the safety standards. No. Thus, optical measurement technology has advantages that PET and fMRI do not have in real-time measurement and quantification of dye concentration in living organisms, and is suitable for miniaturization of equipment and simplicity of handling. .

Utilizing the advantages of the above-mentioned optical measurement technology, the living body is irradiated with light having a wavelength in the visible to infrared region, and the light (reflected light) that is absorbed and scattered in the living body and comes out of the living body again is detected. For example, Japanese Patent Application Laid-Open No. 57-11532, Japanese Patent Application Laid-Open No. 63-260532, Japanese Patent Application Laid-Open No. This is described in, for example, Japanese Patent Application Laid-Open No. 27532/23, Japanese Patent Application Laid-Open No. Hei 5-3-172595, and the like.

However, the above-described conventional biological measurement technique using light can measure only a specific position or a limited narrow area in a living body, and does not consider imaging measurement of a wide space area in the living body.

Here, the specific problems in the light measurement method and the arrangement of the light irradiation point and the light detection point in the conventional technology will be described.

First, the optical measurement method will be described. For imaging measurement in a large space area, light irradiation and light detection at multiple points are required. An example of this multi-point measurement will be briefly described with reference to FIG. In this example, light is emitted from three places (irradiation position 1, irradiation position 2, and irradiation position 3) on the subject surface, and reflected light is reflected from three places (detection position 1, detection position 2, and detection position 3) on the subject surface. ) Shows the case of detection. In the case of imaging measurement, the measurement position must be specified. For light propagation in a light scatterer (for example, in a living body), for example, "NC Bruce;" Experimental study of the effect of absorbing and transmitting inclusions in highly scattering media ", Applied Optics, vol.33, no.28, pp.6692-6698, (Oct. 1994) J The experimental results are shown in Fig. 3. From Fig. 3, it is known that the vicinity of the midpoint between the light irradiation position and the light detection position contains a lot of information deep in the surface. When measuring a deep part of a living body, for example, a deeper part of skin or bone, from above the skin, the midpoint position between the irradiation position and the detection position is the measurement target position K. In such a measurement, the irradiation position is It is necessary to determine the information at the measurement position S (measurement position 1, measurement position 2, measurement position 3) specified for each pair by pairing the detection position with the detection position.

For example, in the arrangement shown in Fig. 2, light is emitted simultaneously from three light irradiation points (irradiation positions 1, 2, 3), and reflected light is detected at three light detection points (detection positions 1, 2, 3) simultaneously. Think about it. In this case, in the measurement at the measurement position 2 which is the midpoint between the irradiation position 2 and the detection position 2, it is necessary to accurately measure only the reflected light of the light irradiated at the irradiation position 2 at the detection position S2. However, actually, the light detected at the detection position 2 includes not only the reflected light of the light irradiated from the irradiation position 2 but also the reflected light of the light irradiated from the irradiation position 1 and the irradiation position 3. Especially, so-called crosstalk occurs. Therefore, only the reflected light of the light irradiated at the irradiation position 2 cannot be separated and detected at the detection position 2, and accurate measurement at the measurement position 2 cannot be performed.

Therefore, if the irradiation positions are sequentially switched in time series for each measurement position by using a switching switch or the like, such crosstalk does not occur.However, in order to sequentially switch a large number of irradiation positions, It takes a lot of time to switch, which is inefficient because it takes a long time to measure.

Therefore, for imaging measurement of a large spatial area within the subject, the development of multi-channel simultaneous measurement technology that can perform measurement at many measurement positions inside the subject simultaneously and without crosstalk is strongly required. It is where it is requested.

In addition, in vivo measurement, especially brain function measurement, in the brain covered with the scalp or skull Information needs to be measured with high sensitivity and efficiency. In the optical measurement method, such information on a deep part in a living body is detected at a middle point between a light irradiation point and a light detection point. Here, as a method of measuring this deep information with high sensitivity, that is, so as to include more deep information, a plurality of pairs of light irradiation points and light detection points are arranged on the circumference surrounding the part to be measured. If the midpoint position of the pair is made common, it will be possible to measure the information of the deep part in the living body corresponding to the common midpoint position with high sensitivity. However, in this case, too. In order to perform accurate measurement in a short time, the above-mentioned clock measurement of multiple pairs of light irradiation points and light detection points, that is, simultaneous measurement of multiple channels is performed without crosstalk. Must.

Furthermore, at present, operations and input of information of various devices represented by computers are performed through keyboards and switches, but such operations and information input operations are difficult for persons with physical disabilities. Often. In addition, even a healthy person may not always be able to take prompt and accurate measures, for example, in the event of an emergency in driving a car or operating a large-scale plant. In such a case, prior to the limbs of the operator to react, if it is possible to take a more accurate measure a good Li quickly, where _υ it is possible to prevent the occurrence of serious accidents, the operator of the brain One possible method is to measure the activity of the perception and cognition functions in the real-time, and to directly input signals related to changes in brain activity to the above devices. However, high-sensitivity and high-precision measurement of brain activity is indispensable to ensure that operations are performed in such a way. For this reason, simultaneous measurement of multiple channels as described above requires crosstalk. There is a need for a technology to do this without. Disclosure of the invention

Therefore, an object of the present invention is to provide a biological light measurement technique that enables highly efficient and accurate light measurement in a wide space area within a subject (living body).

Another object of the present invention is to enable optical measurement over a large spatial area in a subject. An object of the present invention is to provide a small and easy-to-handle biological optical measurement device.

Still another object of the present invention is to provide a multi-channel simultaneous measurement method capable of simultaneously performing optical measurement at a plurality of measurement positions in a subject without crosstalk.

Still another object of the present invention is to provide a biological optical measurement device capable of measuring information in a deep part inside a subject with high sensitivity.

Still another object of the present invention is to use a biological measurement signal having a high spatial resolution obtained from the above-described biological optical measurement device as an input signal to control various external devices with high accuracy. It is to provide a high biological input device and a high biological control device.

In order to achieve the above object, according to the present invention, light having a wavelength in the visible to infrared region is simultaneously irradiated into the subject from a plurality of irradiation sites on the surface of the subject (living body), passed through the subject, and re-transmitted. In a biological optical measurement device for simultaneously detecting light emitted outside the subject at a plurality of detection sites on the surface of the subject and imaging and measuring biological information inside the subject using the detection signals, Irradiation light from the irradiation part is intensity-modulated at a different modulation frequency for each irradiation part, and at the plurality of detection parts, light having a different modulation frequency is detected for each detection part. are doing. According to the configuration of the present invention described above, the detection light of the specific modulation frequency detected at the specific detection part corresponds to only the irradiation light from the specific irradiation part irradiated with the light of the specific modulation frequency. Therefore, it is possible to obtain biological information at a specific measurement site in the subject that is determined corresponding to the specific irradiation site and the specific detection site without crosstalk. As a result, biological information on a plurality of measurement sites in the subject can be obtained simultaneously and without crosstalk, and multi-channel simultaneous measurement becomes possible. In addition, highly efficient and accurate optical measurement can be performed on a wide spatial area including a plurality of measurement sites in the subject.

In the configuration of the present invention described above, the light selectively detected at each detection site is converted into another light. By changing to the light of the modulation frequency, the biological information at another measurement part in the subject determined in correspondence with the irradiation part irradiated with the light of the other modulation frequency and the detection part detecting the same can be obtained without crosstalk. be able to. As a result, the number of irradiation sites and detection sites required for measurement of a predetermined number of measurement sites can be reduced. Therefore, the number of light sources for light irradiation and the number of detectors for light detection can be reduced, and a compact and easy-to-handle device configuration can be obtained.

Further, according to the present invention, as described above, it is possible to perform measurements on a plurality of measurement channels formed between a plurality of light irradiation points and a plurality of light detection points simultaneously and without crosstalk. The plurality of pairs of light irradiation points and light detection points are arranged on a circumference surrounding a specific measurement site in the deep part of the subject, and the midpoint position (measurement position) of each pair is determined by this specific measurement site. By this, only the information on the specific measurement site can be selectively and intensively detected. Therefore, it is possible to measure biological information at a specific site deep inside the subject with high sensitivity.

Furthermore, according to the present invention, as described above, a biological optical measurement device capable of measuring biological information about a wide spatial region in a subject (living body) with high efficiency, high accuracy, and high spatial resolution can be realized. By using the measurement β from the biological optical measurement device directly as an input signal of various external devices, a highly practical biological input device and a biological control device capable of controlling these various external devices quickly and with high accuracy. The device can be realized. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing a schematic configuration of a biological light measurement device according to a first embodiment of the present invention, and FIG. 2 is a diagram showing a positional relationship between a light irradiation position, a light detection position, and a measurement position in biological light measurement. ,

FIG. 3 is a diagram showing light propagation in a living body (light scattering body) in living body light measurement. FIG. 4 is a light irradiation position for realizing more efficient living body light measurement according to the present invention. Diagram showing the positional relationship between the light detection position and the measurement position,

FIG. 5 is a diagram showing a specific configuration of each optical module in the embodiment shown in FIG. 1, and FIG. 6 is a light irradiation position, a light detection position, and a measurement position on the surface of the subject in the embodiment shown in FIG. Diagram showing the positional relationship between positions,

FIG. 7 shows a specific configuration of the lock-in amplifier module in the embodiment shown in FIG. ,

FIG. 8 is a diagram showing the shape of the probe in the embodiment shown in FIG.

FIG. 9 is a diagram showing a specific configuration of the probe in the embodiment shown in FIG. 1, and FIG. 10 is a diagram showing a configuration of a light source unit in the biological optical measurement device according to the second embodiment of the present invention.

FIG. 11 is a diagram showing the specific configuration of the optical modulator in the embodiment shown in FIG. 10, and FIGS. 12, 13, and 14 are diagrams showing the measurement sensitivity distribution and the production sensitivity in the in-vivo measurement according to the conventional technology. Diagram showing the relationship with body depth,

FIG. 15 is a diagram showing a schematic configuration of a biological optical measurement device S according to a third embodiment of the present invention. FIG. 16 is another configuration example of the data collection unit in the embodiment shown in FIG. Figure showing

FIG. 17 is a diagram showing still another configuration example of the data collection unit in the embodiment shown in FIG.

FIG. 18 is a diagram showing still another configuration example of the data collection unit in the embodiment shown in FIG.

FIG. 19 is a diagram showing still another configuration example of the data collection unit in the embodiment shown in FIG.

FIG. 20 is a diagram showing still another configuration example of the data collection unit in the embodiment shown in FIG.

FIG. 21 is a diagram showing another example of the positional relationship between the irradiation optical fiber and the condensing optical fiber in the embodiment shown in FIG. 15, FIG. 22 is a diagram showing still another example of the positional relationship between the irradiation optical fiber and the converging optical fiber in the embodiment shown in FIG.

FIG. 23 is a diagram showing still another example of the arrangement relationship between the irradiation optical fiber and the condensing optical fiber in the embodiment shown in FIG.

FIG. 24 is a diagram showing a schematic configuration of a living body optical measurement device suitable for measuring deep in-vivo information according to a fourth embodiment of the present invention.

FIGS. 25, 26 and 27 are diagrams showing the relationship between the measurement sensitivity distribution and the depth in the living body in the in-vivo measurement using the device S configuration shown in FIG.

FIG. 28 is a diagram showing a schematic configuration of a brain function activity measuring device used in a living human power device according to a fifth embodiment of the present invention.

FIG. 29 is a diagram showing an example of a change in the concentration of the mog mouth bin into the brain during right finger movement measured by the apparatus configuration shown in FIG.

FIG. 30 is a diagram showing an example of a change in the concentration of the mog mouth bin into the brain during the movement of the left finger measured by the device configuration shown in FIG.

Fig. 31 is a contour map showing an example of changes in total hemoglobin concentration in the brain during right finger movement measured by the device configuration shown in Fig. 28.

Fig. 32 is a contour map showing an example of the change in the total concentration of the hemagglutinating bin in the brain at the time of recalling the language measured by the device configuration shown in Fig. 28.

FIG. 33 is a diagram showing a schematic configuration of a biological control device according to a fifth embodiment of the present invention. FIG. 34 is a first example of an arithmetic procedure in the arithmetic device in the embodiment shown in FIG. Flow chart showing

FIG. 35 is a flowchart showing a second operation procedure example in the operation device in the embodiment shown in FIG.

FIG. 36 is a diagram showing the data structure of learning data used in the second example of the operation procedure shown in FIG.

FIG. 37 is a diagram showing a schematic configuration of a biological control device according to a sixth embodiment of the present invention. , The best mode for carrying out the invention

Hereinafter, the present invention will be described in detail with reference to the drawings.

《Multi-channel simultaneous measurement》

In the present invention, in order to enable high-efficiency and high-precision optical measurement in a wide space area within a subject (cow), optical measurements at a plurality of measurement positions in the subject are performed simultaneously and without crosstalk. A multi-channel simultaneous measurement technique that can be performed is provided.

That is, in the present invention, in order to solve the above-described crosstalk problem, light having a wavelength in the visible to infrared region is simultaneously irradiated into the subject from a plurality of irradiation positions on the surface of the subject (living body). Biological light measurement that simultaneously detects light that passes through the sample and is emitted outside the subject again at multiple detection positions on the surface of the subject, and uses this detection signal to image and measure biological information inside the subject. In the apparatus, the modulation frequency of the light radiated into the subject from the plurality of irradiation positions is made different for each irradiation position, and at the plurality of detection positions, the light having the different modulation frequency is different for each detection site. It is configured to selectively separate and detect.

For example, in FIG. 2, light whose intensity is modulated at different modulation frequencies f 1, f 2, and f 3 is simultaneously irradiated from irradiation positions 1, 2, and 3, respectively. Then, at the detection positions 1, 2, and 3, only the lights of the modulation frequencies ί1, f2, and f3 are selectively separated and detected corresponding to the irradiation positions 1, 2, and 3, respectively. Thus, for example, at the detection position 2, only the light of the modulation frequency f2 irradiated from the irradiation position 2 and passed through the subject (living body) is irradiated, and the light of the modulation frequencies ί1 and ί3 radiated from the irradiation position 3 And can be selectively detected. That is, the detection light at the detection position 2 includes only the light component emitted from the irradiation position 2 and does not include the light component emitted from the other irradiation positions 3 at all. Therefore, the light with the modulation frequency f 2 selectively detected at the detection position 2 (light passing through the living body) Is a force that includes much in-vivo information at measurement position 2 between irradiation position 2 and detection position 2, and hardly includes in-vivo information at measurement positions 1 and 3. In other words, information about the other measurement positions 1 and 3 is not mixed in the information about the measurement position 2 to be measured at the detection position 2. This is exactly the same for the other detection positions 1 and 3. Thus, measurement without crosstalk can be performed at each measurement position. In addition, in order to quantitatively measure the concentration of pigments such as hemoglobin, cytochrome aa :,, and myoglobin in the bovine body, multiple light beams with different wavelengths are used as the irradiation light to the living body and pass through the living body. In the case where the measured light is spectrally measured by wavelength, it is possible to irradiate the plurality of irradiation lights by assigning different modulation frequencies to the respective wavelengths. In this case, the light passes through the same measurement position and passes through the same detection position. By separating and detecting (lock-in detection) a plurality of light beams having different wavelengths that have arrived at each modulation frequency, the light of multiple wavelengths can be reflected and scattered by optical filters, diffraction gratings, prisms, and the like. Electrical spectrometry can be performed without using optical spectroscopy with loss. In addition, if the above-described method of modulating the irradiation light with different modulation frequencies is used, the irradiation frequency from different irradiation positions is also detected at each detection position by changing the modulation frequency of the light selectively detected at each detection position. can do. For example, in FIG. 2, if the modulation frequencies of the irradiation light from irradiation positions 1, 2, and 3 are f1, f2, and f3, respectively, the modulation frequency of the detection light at the detection position g2 is f2. If they are matched, only the irradiation light from the irradiation position 2 is selected and detected at the detection position 2. However, if the modulation frequency of the detection light at the detection position 2 is changed to f1 and f3, the irradiation position S Only the irradiation light from 1 and 3 can be selectively detected. The same applies to detection positions 2 and 3. This advantage is related to more efficient light irradiation and detection point arrangement.

When a specific irradiation position and detection position are exclusively assigned to each measurement position for a plurality of measurement positions, i.e., when there are three measurement positions as shown in Fig. 2, the irradiation position and the detection position Three positions are required for each. So, for example, As shown in Fig. 4, the irradiation position 2 and the detection positions 1 and 2 are alternately arranged in a grid pattern, and the irradiation position 1 is shared by the measurement positions 1 and 4 and the irradiation position 2 is shared by the measurement positions 2 and 3 If the force, force, and detection position 1 can be shared with measurement position 2 and detection position 2 can be shared with measurement positions 3 and 4, the required irradiation position and detection position for a total of 4 measurement positions can be obtained. In two places each. That is, according to the modulation measurement method described above, the modulation frequencies of the irradiation light from the irradiation positions 1 and 2 in FIG. 4 are set to f 1 and f 2, and the modulation frequencies of the detection light at the detection positions 1 and 2 are set. When the frequency is adjusted to f1, information on the measurement positions 1 and 4 can be selectively measured at the detection position 2, and when the modulation frequency of the detection light at the detection positions 1 and 2 is adjusted to f2, the detection position 1 , 2 can select and measure information about measurement positions 2 and 3, respectively. As a result, the number of irradiation positions (and thus the number of light sources associated therewith) and the number of detection positions (and therefore the number of detectors associated therewith) can be greatly reduced, thereby improving system efficiency and reducing the size of the device configuration. Thus, the handling can be simplified.

Hereinafter, the present invention will be described in detail with reference to examples.

FIG. 1 shows a schematic configuration of a biological optical measurement device according to a first embodiment of the present invention.

In the present embodiment, the number of measurement channels (that is, the number of measurement positions [the number of S]) was set to 64, assuming that the inside of the cerebrum was imaged and measured by irradiating and detecting light from the skin of the human head, for example. The device configuration will be described.

The light source unit 1 is composed of 16 optical modules 2 (1), 2 (2),... 2 (16). Each optical module is composed of three semiconductor lasers that individually emit light of multiple wavelengths within the visible to infrared wavelength range (for example, three wavelengths of 770 nm, 805 nm, and 830 nm). It is configured. All (48 total) semiconductor lasers included in the light source unit 1 receive modulation signals from the oscillation unit 3 composed of 48 oscillators having different oscillation frequencies, and receive different modulation frequencies. Emit laser light modulated by. Fig. 5 shows the specific configuration inside each optical module. In the optical module 2 (1), semiconductor lasers 3 (1-a), 3 (1-b), 3 (1-c) and driving circuits 4 (Ia), 4 (1-b), 4 (1-c) is included. Here, in the code given to each component, the number (1) in parentheses indicates that the element belongs to the optical module of module number 1, and the alphabetic characters (a, b, c) indicate the wavelength, respectively. This indicates that the element is included in the circuit system that outputs laser light with a (770 nm), wavelength b (805 nm), and wavelength c (830 nm). Drive circuits 4 (1-a), 4 (l ~ b), and 4 (1-c) output different modulation frequencies f (Ia) and f (1-b) from the respective oscillators in the oscillator 3. , f (1-c), the modulation frequency corresponding to the output laser light from semiconductor lasers 3 (1-a), 3 (1-b), and 3 (1-c) is supplied. Gives the modulation in Output laser beams from the respective semiconductor lasers are individually introduced into the optical fiber 6 via the condenser lens 5. The light introduced into each optical fiber 6 is introduced into one irradiation optical fiber 8-1 via an optical fiber coupler 7.

In this way, for each optical module, three lights having different wavelengths are introduced into the irradiating optical fibers 8-1, 8-2,. Light having passed through the irradiation optical fiber is simultaneously irradiated into the subject 9 from 16 different irradiation positions on the surface of the subject 9. From each irradiation position, three types of light having different wavelengths and modulation frequencies are simultaneously irradiated, so that a total of 48 types of light are simultaneously irradiated into the subject 9.

Next, the reflected light from the subject 9 (the light that is absorbed and scattered by passing through the subject and emitted from the subject surface to the outside) is detected at a total of 25 locations on the subject surface. It is taken into the detection optical fibers 10 0-1, 10-2,.

FIG. 6 shows an example of the geometric arrangement of the irradiation positions (IP) 1 to 16 and the detection positions (DP) 1 to 25 on the surface of the subject 9. In this embodiment, the irradiation position (IP) and the detection position (DP) are alternately arranged in a square lattice. Here, the irradiation position (! P) and the detection position adjacent to each other Assuming that the midpoint of (DP) is the measurement position (MP), in this example, there are 64 combinations of the irradiation position (IP) and the detection position (DP) that are adjacent to each other. The number, that is, the number of measurement channels is 64.

Here, when the subject 9 is a human head, if the distance between the irradiation position and the detection position adjacent to each other is set to about 3 cm, the detection light at each irradiation position has information in the cerebrum, It is reported in \ f "PW McCormic;" Intracerebral penetration of infrared light ", J. Neurosurg., Vol.76, pp.315-318, (1992). Therefore, if a total of 64 measurement channels are set in the arrangement shown in FIG. 6, it is possible to measure intracerebral information in a wide area of about 15 cm × 15 cm as a whole. The reflected light captured by each detection optical fiber 10-1 to 10-25 is a total of 25 photodetectors (for example, photodiodes) 11-1-1, 11-2, ...

According to 1 1 1 2 5, detection is performed independently for each detection position (that is, for each detection optical fiber). The output electric signal from each photodetector is measured separately by a lock-in amplifier module 12 composed of a plurality of lock-in amplifiers for each modulation frequency corresponding to the irradiation position and the wavelength of the irradiation light.

Here, a specific example of the signal separation method will be described with reference to FIG. 7, taking the detection signal at the detection position (DP) 7 in FIG. 6, that is, the detection signal at the photodetector (photodiode) 11-17 as an example. . At the detection position (DP) 7, the light irradiated from the four irradiation positions (1P) 2, 5, and 6 adjacent to it, that is, the measurement positions (MP) 10, 11, 18, 18,

The light passing through 19 is targeted for detection. Here, the light detected by the photodetectors 11-17 mainly consists of the modulation frequencies から (1 a), f (1-b) radiated from the irradiation positions (] P) 1, 2, 5, and 6. , f (1-c), f (2-a), f (2-b), f (2-c), f (5-a), f (5-b), f (5-c), f (6-a), f (6-b) and f (6-c) are included. Therefore, the output signals of the photodetectors 11 and 17 are used as reference signals for the corresponding modulation frequencies. The two lock-in amplifiers 13—31, 13-32,. Divided and input to -42 to separate and amplify each modulation frequency. For example, lock-in amplifier 1 3— In 3 1, since the reference signal frequency is set to f (1-a), the wavelength from the irradiation position (IP) 1 is 7770 nm from the optical signal detected by the photodetector 11. Only the signal components corresponding to the irradiating light (that is, the light whose modulation frequency is f (1-a)) are separated and selected and amplified. That is, the output signal from the lock-in amplifier 13-31 is applied to the light of wavelength 770 nm at the measurement position (MP) 10 existing between the irradiation position (IP) 1 and the detection position (DP) 7. It contains only biological reaction information such as absorption and scattering. Similarly, in other lock-in amplifiers, only light of a specific wavelength irradiated from a specific irradiation position is selectively detected.

In this way, the optical signals detected at other detection positions, that is, the detection signals from the other photodetectors, are also modulated at the specific modulation frequencies determined corresponding to the light irradiation position and the irradiation light wavelength, respectively. By separately performing the mouth lock-in detection, it becomes possible to separately measure the amount of light detected for all measurement positions and the irradiation light wavelength. In the case of performing measurement with three wavelengths at the 64 measurement positions shown in the present embodiment, a total of 19 2 lock-in amplifiers 1 3— 1, 1 3—2, · '· · 1 3— 19 2 are included.

The analog output signals from these 192-channel lock-in amplifiers are converted into digital signals by a 192-channel AZD converter 14, passed through a control unit 18, and recorded in a data recording unit 15. You. In addition, these recorded signals are used in the data processing unit 16 by using the detected light amount of three waves at each measurement position, to obtain the oxygen concentration in the oxygenated hemoglobin, the oxygenated hemoglobin concentration, and the oxygenated hemoglobin concentration. The total hemoglobin concentration as a total amount was calculated using the method described in the book, `` Two-Wavelength Spectrophotometry and Its Applications, '' edited by Shodan Shibata et al., Published in 1979 by Kodansha. Ask.

In addition, the oxygenated hemoglobin concentration, the deoxygenated hemoglobin concentration, and the total hemoglobin concentration determined for each measurement position are displayed on the display unit 17, for example, in topography. Display as an image. Note that the data for displaying the topography image is obtained by, for example, interpolating (for example, linearly interpolating) the densities of the bins at each measurement position between the measurement positions. The operation of each unit of the apparatus described above is controlled by the control unit 18. For light irradiation and light detection on the subject (human head), for example, a helmet or cap-shaped probe 21 as shown in FIG. 8 is used. For this probe 21, for example, a thermoplastic resin sheet having a thickness of about 3 mm is used as a base material, and a mold is formed in advance with the base material to match the external dimensions in the measurement region of the subject. This is fixedly mounted on the outer surface of the subject with, for example, a rubber cord 22 or the like. An example of a more specific structure of the probe 21 will be described with reference to FIG. Holes are provided in the probe base 23 at a plurality of positions corresponding to the irradiation position of the light on the subject 9 and the detection position of the reflected light from the subject 9, and the optical fiber holder 24 is fixedly mounted in each hole. The optical fiber holder 24 includes a hollow cylindrical holder main body 24, a main body fixing screw 25 and an optical fiber fixing screw 26, and the holder main body 24 is inserted into each hole provided in the probe base 23. Then, the holder main body 23 is fastened and fixed to the probe base 23 with the main body fixing screws 25. Then, an irradiation optical fiber or a detection optical fiber is inserted into the center hole of the holder body 23, and the end of the optical fiber is lightly brought into contact with the surface of the subject 9; Fix it with it.

In this embodiment, the case where the number of measurement channels is 64 has been described. However, it goes without saying that the present invention is not limited to this number of channels. The present embodiment can be easily applied to a so-called optical CT device in which tomography of the inside of a living body is performed using light, and the obtained data is image-processed by a computer.

According to this embodiment, it is possible to efficiently and temporally and systematically perform image measurement of information inside a living body in a wide space area, and to obtain a small-sized and simple biological light measuring apparatus.

Example 2> FIG. 10 shows a schematic configuration of a biological light measurement device according to a second embodiment of the present invention. In this embodiment, the basic configuration of the measurement system is the same as that of the first embodiment.

The configuration of 1 is different. FIG. 10 shows the configuration of the light source unit 1 in the second embodiment.

A light source having a wavelength of 770 nm, for example, a semiconductor laser 31 is driven by a laser drive circuit 41 and emits continuous light without modulation. This light is introduced into the optical fiber 61, and is distributed through the optical fiber coupler 51 to 16 optical fibers 61-1-1 to 61-1-16.

Each of these 16 optical fibers includes an optical modulator 71-1 to 71-16 in its path. The configuration of these optical modulators is shown in FIG. 11 using the optical modulator 71-1 as an example. For example, a liquid crystal filter 101 is built in the optical modulator 711, and the liquid crystal filter 101 is periodically turned on and off when a modulation voltage signal is applied from an oscillator in the oscillation unit 3. Is to repeat. For example, in the optical modulator 711, a modulation voltage signal having a modulation frequency of f (1−a) is applied to the liquid crystal filter 101. The light from the optical fiber 6 1-1 is applied to the liquid crystal filter 101 via the lens 5, and the light transmitted through the liquid crystal filter 1 1 is condensed by the lens 5 to form the optical fiber 8 1-1. Will be introduced. Here, the optical modulators 7 1-1 to 7 1 _ 16 have different modulation frequencies, for example, f (1- _a ), f (2-a), f (16-a) The LCD filter is turned on and off. It should be noted that, as the optical modulator, a device using a rotary mechanical optical disc may be used in addition to the liquid crystal filter. In this way, the light beams modulated at the different modulation frequencies by the optical modulators 71-1-1 to 71-1-16 are introduced into the optical fibers 81-1 to 81-1-16 and transmitted.

Similarly, light sources of other wavelengths in the light source unit 1 (for example, semiconductor lasers with wavelengths of 805 and 830 nm) 32 and 33 are driven by laser driving circuits 42 and 43, respectively. Output lights from these light sources 32 and 33 are sent to fiber couplers 52 and 53 via optical fibers 6-2 and 6-3, respectively, and 16 optical fibers 62-1 to 16 are respectively provided. It is distributed to 6 2—16, 6 3—1 to 6 3—16. The light distributed to the optical fibers 6 2—1 to 6 2—16, 6 3—1 to 6 3—16 is converted to optical modulators 7 2—1 to 7 2—16,

7 3-1 to 7 3-16 are modulated at different modulation frequencies. That is, each of the optical modulators 72-1 to 72-16 has a different modulation frequency f (l-b), f (2-b),... F (16-b) The signal is applied and the optical modulator 7 3— 1

The modulation signals having different modulation frequencies f (l-c), f (2-c) and f (16-c) are applied to. The light that passed through the optical modulators 7 2—1 to 7 2—16 passed to the optical fibers 8 2—1 to 8 2—16 and the optical modulators 7 3—1 to 7 3—1 16 respectively. The light is respectively introduced into optical fibers 83-1 to 83-16 and transmitted.

In this way, a total of 48 optical modulators 7 1-1 to 7 1-16, 7 2-1 to 7 2-16 and 7 3-1 to 7 3-16 are individually modulated, Total 4 8 optical fibers 8 1-1 to 8 1-16, 8 2-1 to 8 2-16 and 8 3-1 to 8 3-16 Independently transmitted and modulated respectively Next, a total of 48 types of light having different frequencies are grouped for each wavelength and introduced into one (total of 16) optical fibers in the following way: Optical fiber 8 1 — 1, 8 2-1 and

The light transmitted by 83-1 is collectively introduced into one irradiation optical fiber 8-1 via the optical fiber coupler 911. Similarly, the light transmitted through the optical fibers 8 1-16, 8 2-16 and 8 3-16 is converted into one irradiation optical fiber 8 by the optical fiber coupler 9 1 1 16. Introduced together in 16. In this way, 16 types of irradiation optical fibers 8-1 to 8-16 are used to carry out three types of light (48 types in total) with different wavelengths and modulation frequencies. The surface of the subject 9 is irradiated in the same manner as in the example. Note that the method of measuring the reflected light from the subject 9 is the same as in the first embodiment.

According to this embodiment, it is possible to efficiently and temporally and systematically perform image measurement of information inside a living body in a wide space area, and the device configuration is small and simple. A device is obtained.

《High-sensitivity measurement of deep body information》

According to the present invention, there is also provided a biological optical measurement device capable of measuring information in a very small area in a deep city in a subject (living body) with high sensitivity and high resolution.

Conventionally, a living body is irradiated with light having a wavelength in the visible to infrared region, and reflected light from a deep region in the living body at a distance of about 10 to 50 mm from the irradiation position is detected, and biological information on the deep region is obtained. Such a living body optical measuring device is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 63-277038 and 5-30087. However, with this type of conventional apparatus, it is difficult to obtain biological information on a minute region deep inside the living body with sufficient measurement accuracy.

In other words, cattle using light. In body measurement, the irradiated light spreads greatly in the living body due to the strong light scattering characteristics (scattering coefficient = about 0 [1 / 丽]) in the living body. The measurement results include information over a wide area in the living body. In particular, there is a problem in that the spatial characteristics of the detection sensitivity are such that the sensitivity in a shallow part of a living body near the light irradiation position and the light detection position is greater than the sensitivity in a deep part. For this reason, it is difficult to accurately measure a change in the concentration of a light absorbing substance in a deep region in a living body by a method that has been conventionally proposed. For example, when measuring the hemodynamic change of the living brain from above the scalp, there is a problem in that the hemodynamic change in a relatively shallow region immediately below the scalp is largely reflected in the measured value for the above-described reason.

Figs. 12 to 14 show examples of the results of obtaining the relative sensitivity distribution with respect to the change in the concentration of the light absorbing substance in the living body using the above-mentioned conventional technology. Here, the surface of the living body is assumed to be a plane, and the plane parallel to the surface of the living body is defined as the X-Y plane, and light enters the living body from the position x = 32.5 mm, y = 17.5 mm on the surface of the living body. And a sensitivity distribution at a depth of 2.5 mm when this irradiation light is condensed at x = 32.5 mm, y = 47.5 mm at a position 30 distant from the light irradiation position Figure 12 shows the relative sensitivity distribution at a depth of 7.5 mm, and Figure 13 shows the relative sensitivity distribution at a depth of 12.5 mm. These are shown in Figure 14 respectively. From these figures, it can be seen that the relative sensitivity distribution in the in-vivo surface region (Fig. 12) is high and steep, but the relative sensitivity distribution in the in-vivo deep region (Fig. 14) is low and blunt. As described above, the influence of light absorption and light scattering in the surface region in the living body is extremely large. Therefore, it is difficult to measure the concentration change of the light absorbing substance in the deep region in the living body with high accuracy by the conventional technology. is there.

Therefore, in the present invention, when irradiating light into the subject from a plurality of light irradiation positions on the subject surface, and condensing and detecting light transmitted through the subject at a plurality of light detection positions on the subject surface, The plurality of light irradiation positions and the plurality of light irradiation positions are so set that the respective light paths of the light (transmitted light) irradiated from each of the plurality of light irradiation positions and transmitted through the subject overlap each other in a desired measurement region in the subject. An arrangement relationship with the plurality of light detection positions is set, and light detection signals at the plurality of light detection positions are arithmetically processed, thereby increasing the detection sensitivity to the optical information in the desired measurement area. (The detection sensitivity for optical information in other areas is relatively reduced.)

Hereinafter, the characteristic configuration of the present invention described above will be described in more detail.

The biological optical measurement device for deep information measurement inside a subject (living body) according to the present invention is basically for irradiating a plurality of irradiation lights having different wavelengths from a plurality of irradiation positions on the surface of the subject into the subject. A light irradiating means having a plurality of irradiating portions; and a light irradiating means for condensing light (transmitted light) irradiated from each of the plurality of light irradiating positions and transmitted through the subject at a plurality of detecting positions on the surface of the subject. A plurality of collections provided in an arrangement such that the optical paths of the respective lights (transmitted light) emitted from each of the plurality of irradiation units and transmitted through the subject overlap with each other in a predetermined measurement region in the subject. A light condensing means having an optical part; and a plurality of light detectors for detecting light intensities of the respective transmitted lights condensed by the plurality of light condensing parts at each of the plurality of irradiation positions and each of the plurality of wavelengths. Have department That the light detecting means, or the from the light intensity detection signal from the plurality of light detection section, to improve the measurement sensitivity of the optical information in the predetermined measurement region within the object Arithmetic processing means for performing arithmetic processing for lowering the measurement sensitivity of optical information in an area other than the predetermined measurement area to obtain optical information in the predetermined measurement area.

In addition, the above-mentioned plurality of irradiation lights are subjected to intensity modulation at different modulation frequencies for each irradiation position and each wavelength, and a predetermined modulation frequency is obtained from the transmitted light condensed by each of the condensing sections. By separating and detecting (lock-in detection) only the light component that is intensity-modulated by, or by calculating the detection signal of the transmitted light condensed by each of the condensing parts, the irradiation position and wavelength The light intensity of each transmitted light component may be obtained. Further, the transmitted light condensed by each of the condensing sections is separated by a spectroscope for each wavelength, and only the light component intensity-modulated at a predetermined modulation frequency is separated and detected from the separated wavelength components ( By performing lock-in detection, the light intensity of the transmitted light component for each irradiation position and each wavelength may be obtained. Here, the optical information to be measured is a light absorption coefficient in the subject (living body).

Further, according to the present invention, there is provided a photoelectric conversion device that converts transmitted light having a predetermined intensity modulation frequency (or transmitted light having a predetermined wavelength having a predetermined intensity modulation frequency) into a transmitted light intensity signal having the predetermined intensity modulation frequency by photoelectric conversion. A conversion unit and a phase detection unit to which a transmitted light intensity signal from the photoelectric conversion unit is input, the phase detection unit is configured to apply the intensity modulation frequency given to the irradiation light of each wavelength from each light irradiation position. By inputting a corresponding reference signal, a signal corresponding to the intensity of the transmitted light component having a predetermined intensity modulation frequency can be output from the phase detector. Alternatively, using the photoelectric conversion unit and a D (analog-to-digital) conversion unit to which a transmitted light intensity signal from the photoelectric conversion unit is input, the transmitted light intensity signal from the photoelectric conversion unit is transmitted to the AZD conversion unit. Input and obtain a transmitted light intensity signal in the frequency space by Fourier transform, and a signal corresponding to the intensity modulation frequency given for each predetermined light irradiation position or for each predetermined wavelength is sent to the A / D converter. Input and obtain a predetermined reference frequency by Fourier transform. A signal component having a frequency equal to the above-mentioned predetermined reference frequency may be calculated from the transmitted light intensity signal in the frequency space, and this may be used as an intensity signal of the transmitted light component having a predetermined intensity modulation frequency.

The plurality of irradiating units and the plurality of condensing units have at least one predetermined diameter centered on a point at which a perpendicular (a straight line perpendicular to the surface of the subject) passing substantially at the center of the predetermined measurement area intersects the surface of the subject. Can be arranged at equal intervals on a circle having a circle, and such that one irradiating part and one condensing part are paired to form a point-symmetric positional relationship with the center of the circle as a point-symmetric center. . In this case, the transmitted light intensity corresponding to the irradiation light for each wavelength from each light irradiation position is detected for each condensing position and each wavelength, and the transmitted light intensity for each wavelength from each light irradiation position is detected. Select the transmitted light intensity for each wavelength from the light irradiation position that is in point symmetry with the condensing position, and select the transmitted light intensity detected on the same circle from the selected transmitted light intensity Then, an arithmetic process of multiplying or integrating the transmitted light intensity of the transmitted light having the predetermined wavelength detected on the same circle is performed. Further, the intensity of the transmitted light condensed by the light condensing part set on the circle with the smaller diameter is used as information from the shallow part of the subject, and the intensity is set on the circle with the larger diameter. The transmitted light intensity condensed by the condensing portion is used as information from the deep part of the subject, and the transmitted light intensity is subjected to arithmetic processing. It can be arranged in a shape. In this case, the irradiating section and the condensing section are arranged on the grid points of the respective rows of the square lattice so that the row where the irradiating section is arranged and the row where the condensing section are arranged alternately. It is. Furthermore, the plurality of irradiation units and the plurality of light collection units described above can be arranged in a regular hexagonal lattice. In this case, the irradiating section and the condensing section are alternately arranged on each lattice point of the regular hexagonal lattice.

Light having a wavelength near 805 nm is used as light to irradiate the subject (living body). Based on the transmitted light intensity, changes in oxyhemoglobin concentration, changes in reduced hemoglobin concentration, and oxyhemoglobin concentration in the living body can be determined. The change in total hemoglobin concentration calculated as the sum of the change and the reduced hemoglobin concentration change is determined, and the total hemoglobin concentration change is calculated. Change over time can be displayed. Still, the total change in the concentration of moglobin may be obtained directly from the transmitted light intensity. In addition, as irradiation light to the inside of the subject (living body), irradiation light of a plurality of wavelengths (at least two wavelengths) in a wavelength range of 700 nm to 110 nm can be used.

The change in total hemoglobin concentration, the change in oxyhemoglobin concentration, or the change in reduced hemoglobin concentration, which is calculated as the sum of the change in oxyhemoglobin concentration and the change in reduced hemoglobin concentration, is represented by the color of the line, the type of line, or the line shape, respectively. By changing the thickness etc., it is possible to display a diagram. For example, changes in oxyhemoglobin concentration may be displayed in red or orange, changes in reduced hemoglobin may be displayed in blue, indigo or green, and changes in total hemoglobin concentration may be displayed in black or brown. In addition, the images of total hemoglobin concentration change, oxyhemoglobin concentration change, or reduced hemoglobin concentration change calculated as the sum of the oxidized hemoglobin mouth concentration change and the reduced hemoglobin concentration change corresponded to the respective concentration changes. It may be displayed in color or brightness.When the density change is positive, the display is displayed in darker red or higher brightness as the absolute value of the density change value becomes larger, and when the density change is negative, As the absolute value of the value of the density change becomes smaller, the image may be displayed in dark blue or lower luminance.

Further, when a plurality of irradiation units and a plurality of condensing units are arranged on the same circle, the intensity of transmitted light having a predetermined wavelength detected on the circle is set to the surface of the subject through the center of the circle. The change in the oxyhemoglobin concentration change and the reduction in the mog vine bottle concentration change in a predetermined range region of a predetermined depth in the subject on a perpendicular line perpendicular to the predetermined range or a predetermined range region of a predetermined rotating body having the perpendicular as a rotation axis. The calculation can be performed assuming that the change in total hemoglobin concentration, the change in oxyhemoglobin concentration, or the change in reduced hemoglobin concentration calculated as the sum is reflected. In this case, the diameter of the circle can be in the range of 25 mm to 35 mm, and the depth can be in the range of 12 mm to 25 mm. Also, by covering the contact surface of the irradiating section or the condensing section with the object surface with a flexible and highly transmissive member to the irradiation light, the irradiating section or the condensing section is The stimulus given to the subject can be softened.

As described above, the plurality of irradiation units and the plurality of light collection units are arranged on a circle having a predetermined diameter such that the optical paths of the irradiation light from the plurality of irradiation units in the subject overlap each other, At each condensing part, only the transmitted light of the irradiation light from the irradiating part located opposite to it is selectively detected, and the intensity of the transmitted light detected at each condensing part is multiplied to obtain the object surface. It is possible to improve the measurement sensitivity for a region (measurement region) located at a predetermined depth position inside the subject from the center position of the above circle.

As described above, according to the present invention, it is possible to simultaneously and without cross-cutting measurement on a plurality of measurement channels formed between a plurality of light irradiation points and a plurality of light detection points. These plural pairs of light irradiation points and light detection points are arranged on a circumference surrounding a specific measurement site deep inside the subject, and the midpoint position of each pair is determined.

By matching the (measurement position S) to this specific measured part, only the information on this specific measured part can be selectively concentrated. Therefore, it is possible to measure biological information at a specific site deep inside the subject with high sensitivity.

Hereinafter, a living body optical measurement device suitable for measuring deep in-vivo information according to a third embodiment of the present invention will be described.

In this example, two types of light having different wavelengths (two-wavelength light) were used as irradiation light for the purpose of measuring changes in oxidized and reduced hemoglobin concentrations in a subject (living body). Light detection positions are set at two locations, respectively. It is easy to further increase the number (wavelength number) of these irradiation lights, light irradiation positions, and light detection positions. In addition, by increasing the number of irradiation light (number of wavelengths), it is possible to measure not only changes in the concentration of redox hemoglobin but also changes in the concentration of other light-absorbing substances in the living body such as cytochrome and myoglobin. Needless to say.

FIG. 15 shows a schematic configuration of the biological optical measurement device according to the present embodiment. Output light from a plurality (four in this embodiment) of light sources 111, 1-1, 1-3, 114 are respectively illuminated optical fibers 2-i, 2--2, 2-3-3, 2 — Guided to 4. Here, the wavelength of the output light from the light sources 1-1, 1-3 is f1, and the wavelength of the output light from the light sources 1-1, 1-4 is L2. The wavelengths 1 and 2 are selected from the range of 400 nm to 2400 nm. In particular, when measuring hemodynamics in a living body, it is desirable to select a wavelength within the range of 700 nm to 110 nm so that the wavelength difference between them is within 50 nm. Also, the output light from the light sources 111, 112, 113, and 114 is output from 100 Hz by the light source driving circuits 41, 4-2, 4-3, and 4-4, respectively. Intensity modulation is performed at different modulation frequencies f 1, f 2, f 3, and f 4, respectively, during 1 OMHz. The modulation frequency signals A, B, C, and D from the light source driving circuits 4-1, 4-1-2, 4-3, and 4-4 are used as reference frequency signals as phase detectors 27-1 and 27-. 2, 27-3, 27-4 are input.

The optical fibers 2-1 and 2-2 are connected to the optical directional coupler 3-1. The optical fibers 2-3 and 2-4 are connected to the optical directional coupler 2-2. Light from the light sources 1-1, 1-2 is mixed in the optical directional coupler 3-1 and introduced into the irradiation optical fiber 8-1, and light from the light sources 1-3, 1-4 is Are mixed in the optical directional coupler 3-2 and introduced into the irradiation optical fiber 8-2. The irradiation optical fibers 8-1 and 8-2 and the condensing optical fibers 10-1 and 10-2 are fixed by the optical fiber holder 21 and applied to the surface of the subject (human head) 9. Touched.

The object 9 is irradiated with light from the irradiation optical fibers 8-1, 8-2, and the light transmitted through the object 9 through the condensing optical fibers 10-1 and 10-2 (transmitted light). Focus). Here, the irradiation optical fibers 8-1 and 8-2 and the condensing optical fibers 10-1 and 10-2 are arranged on the circumference of one circle set on the optical fiber holder 21. The light-collecting optical fibers 10-1 and 10-2 are arranged at intervals and opposite to the irradiation optical fibers 8-1 and 8-2 with the center of the circle interposed therebetween. Have been. Light The eyeba holder 21 is preferably formed of a black material or coated with a black material in order to enhance the light-shielding property, and preferably has a hollow structure as shown in the figure. The irradiation optical fibers 8-1, 8-2 and the condensing optical fibers 10-1, 10-2 are also covered with a black material on the surface portions other than the contact surface with the subject 9. Is desirable. Further, the contact surfaces of the irradiation optical fibers 8-1, 8-2 and the condensing optical fibers 10-1, 10-2 with the subject 9 are brought into contact with the subject 9 so that the subject 9 It is desirable to apply a coating made of a material that is flexible and has good permeability to irradiation light, such as vinyl resin, for the purpose of reducing the stimulus that will endure.

The light transmitted through the subject (living body) condensed by the converging optical fibers 10 0-1 10-2 is guided to the photodetectors 1 1 1 1 1 and 1 1-2, respectively, and photoelectrically converted. Is detected. Photomultiplier tubes and avalanche photodiodes are used for the photodetectors 10-1 and 10-2. The output signal from the photodetector 10-1 is divided into two and then input to the phase detectors 27-1 and 27-2, respectively, and the output signal from the photodetector 11-2 is also 2 After being divided into two, they are input to the phase detectors 27-3 and 27-4, respectively. The signals input to the phase detectors 27-1, 27-2, 27-3, and 27-4 include the transmitted light intensity signals of all wavelengths of light radiated into the subject (living body). The phase detectors 27-1, 27-2, 27-3, 27-4 have light source driving circuits 4-1, 4, 1-2, 4-3, 4-4 Since the reference frequency signals A, B, C, and D from 4 are respectively input, the phase detector 27-1 applies the wavelength 1 from the light source 111 and the irradiation light with the modulation frequency f 1 Only the corresponding transmitted light intensity component is detected by the phase detector 27-2. Only the transmitted light intensity component corresponding to the irradiation light having the wavelength λ 2 and the modulation frequency ί 2 from the light source 1-2 is detected by the phase detector 27. In the case of —3, only the transmitted light intensity component corresponding to the irradiating light with the modulation frequency f 3 and the wavelength of the light from the light source 1 to 3 are obtained. 2, modulation frequency f 4 Only over the light intensity component permeable corresponding to Shako are respectively separated and detected.

The transmitted light intensity signal component of the wavelength 1 detected by the phase detectors 27-1 and 27-3 is The signal is input to the multiplier 28 1 and multiplied by both signal components, and the wavelengths detected by the phase detectors 27-2 and 27-4; the transmitted light intensity signal component of I 2 is calculated by the multiplier 28 The signal is input to —2 to multiply both signal components. The output signals from multipliers 28-1 and 28-2 are input to log amplifiers 29-1 and 29-2, respectively. Further, the output signals from the log amplifiers 291-1 and 29-2 are input to AZD (analog-digital) converters 141-1 and 14-12, respectively, where they are converted into digital signals. After that, it is taken into the arithmetic unit 30.

The arithmetic unit 30 changes the oxyhemoglobin concentration, changes the reduced hemoglobin concentration, and expresses the blood volume to the oxidized to mog-to-bin concentration change and the reduced to the oxidized hemoglobin concentration based on the time-series signals of the transmitted two-wavelength transmitted light intensities. The sum with the mouth bottle density change is calculated, and the calculation result is displayed on the display device 17 as a time series change graph. Further, when multipoint measurement (measurement for a plurality of measurement regions in the subject 9) is performed by the same device, the measurement result can be displayed on the display device 17 as an image.

When displaying the change of each hemoglobin concentration as a time-series change graph, if the display device 17 can display color, the display color is changed for each change graph of each hemoglobin concentration, and the display device 17 is displayed. When color display is not possible, the type or thickness of the display line can be changed for each change graph of hemoglobin concentration and displayed. For example, if the display device 17 can display color, the change in oxyhemoglobin concentration is red or orange, the change in reduced hemoglobin concentration is blue, indigo or green, and the change in total hemoglobin concentration is black, gray or brown. To display. When displaying the result of the multipoint measurement as an image, the result may be displayed as a contour image, or the display color or the display brightness may be changed in accordance with the change in the density change value. Furthermore, the display may be displayed in deep red or dark gray as the absolute value of the positive density change value increases, and may be displayed in dark blue or pale white as the absolute value of the negative density change value increases.

As the device configuration of the present invention, various modified configurations can be considered with respect to the data collection units from the photodetectors 11-1 and 11-12 to the arithmetic unit 30 shown in FIG. Figure FIGS. 16 to 20 show modified examples of the configuration of these data collection units.

FIG. 16 shows a first modified configuration example of the data collection unit. Note that in this example, the light source 11-1, 1-2, 1-3, 114 to the optical fibers 10-1 and 10-2 for condensing (the light irradiating section and condensing section) The configuration is the same as that in Fig. 15 and those parts are omitted for simplicity. Note that the encircled symbols A, B, C, and D in the figure represent reference frequency signals, as in the case of FIG. These points are the same for the following Figures 17 to 2◦.

In this example, the data collection unit consists of a photodetector 11-1, 1-11, and a phase detector 27-1,

27-2, 27-3, 27-4, A / D converters 14-1, 14-2, 14-3, 14-14, and arithmetic unit 30.

The configuration up to the phase detector 27-1, 27-2, 27-3, 27-4 is the same as that in Fig. 15. The force here is the phase detector 27-1, 27-2, Output signals (transmitted light intensity signals) from 27-3 and 27-4 were converted to digital signals by A / D converters 14-1, 14-14, 1-3 and 14-14, respectively. Later, arithmetic unit

Entered in 30. The arithmetic unit 30 first multiplies the input transmitted light intensity signals of all the wavelengths between the transmitted light intensity signals of the same wavelength, and then calculates the natural logarithm of the result of the multiplication, or The natural logarithm operation is performed on all the transmitted light intensity signals thus obtained, and then the result of the natural logarithm operation is added between the same wavelengths. Here, the combination of the transmitted light intensity signals of the same wavelength described above is the combination of the output signals from the AZD converters 14-1 and 14-13 and the A / D converters 14-1 and 14-4 And two sets of output signals from.

FIG. 17 shows a second modified configuration example of the data collection unit.

The data collection unit of this configuration example includes a photodetector 111, a phase detector 27-11, 27-2, 27-3, 27-4, and a multiplier 28-1, 28. —2, AZD converters 14 1, 14 — 2, and an arithmetic unit 30. Up to the multipliers 28-1 and 28-2, the power is the same as that of the configuration shown in FIG. Output signals from 28-1 and 28-2 are converted into digital signals by the AZD converters 14-1 and 14-2, and then input to the arithmetic unit 30. The arithmetic unit 30 performs a natural logarithmic operation on the signals from the AZD converters 141-1 and 14-12, respectively.

FIG. 18 shows a third modification of the data collection unit.

The data acquisition section of this configuration example consists of a photodetector 1 1 1 1 1, 1 1 2, a phase detector 27-1, 27-2, 27-3, 27-4, and a log amp 29-1, 29- 2, 29-3, 29-4, adders 40-1, 40-2, AZD converters 14-1, 14-2, and an arithmetic unit 30. Phase detectors 27-2, 27-3, 27-4 are the same as the configuration shown in FIG. 15. In this configuration example, the phase detectors 27-1, 27-2, Output signals from 27-3, 27-4 are input to log amps 29-1, 29-2, 29-3, and 29-4, respectively, and are subjected to natural logarithmic conversion. The transmitted light intensity signals (the transmitted light intensity signals of wavelength λ1) from the log amplifiers 29-1 and 29-3 are input to the adder 40-1 and added together, and the log amplifiers 29-1 2, 29-4 The transmitted light intensity signal (the intensity signal of the transmitted light of wavelength 2) is input to the adder 40-2 and added together. Output signals from the adders 40-1 and 40-2 are input to the AZD converters 141-1 and 144-2, respectively, converted into digital signals, and then input to the arithmetic unit 30.

FIG. 19 shows a fourth modification of the data collection unit.

The data acquisition unit of this configuration example consists of a photodetector 11 1 1 1 1 1 1 1 2, a phase detector 27 1 1, 27 2, 27-3, 27 4 2, 29-3, 29-4, an AZD converter 14-1, 14-2, 14-3, 14-14, and an arithmetic unit 30. The configuration up to the phase detector 27-1, 27-2, 27-3, 27-4 is the same as that of Fig. 15, but in this example, the phase detector 27-1, 27-2, 27- The output signals from 3, 27_4 are input to log amplifiers 29-11, 29-2, 29-3, and 29_4, respectively, and are first subjected to natural logarithmic conversion. mouth The output signals from amplifiers 29-1, 29-2, 29-3, and 29-4 were converted to digital signals by AZD converters 14-1, 1, 14-2, 14-3, and 14-4, respectively. Later, it is input to the arithmetic unit 30. In the arithmetic unit 30, the input transmitted light intensity signal is added between transmitted light intensity signals of the same wavelength for all wavelengths. In this example, the combination of the transmitted light intensity signals of the same wavelength described above is determined by the combination of the output signals from the AZD converters 14-1 and 14-3, the AZD converters 14-1 and the A / D converter 13-3 This is a total of two sets including the set of output signals from 4.

FIG. 20 shows a fifth modified configuration example of the data collection unit.

In this example, the data collection unit consists of a photodetector 1 1 1 1, 1 1 1 1 2 and an AZD converter 14 1

1, 14—2, 14—3, 14—4, 14—5, 14—6, and the arithmetic unit 30. The configuration up to the photodetectors 1 1 1 1 and 1 1 1 1 2 is the same as that shown in Fig. 15. In this example, the power from the photo detectors 1 1 1 1 1 1 1 1 1 2 The output signals are input to the AZD converters 14-11 and 144-2, respectively, and are first subjected to AZD conversion. The output signals from the AZD converters 141-1 and 14-12 are directly input to the arithmetic unit 30. A / D converters 14 1-3, 14-4, 14-5, 14-

In 6, reference frequency signals (modulation frequency signals of each irradiation light) Λ, B, C, and D are respectively input and converted into digital signals, and then input to the arithmetic unit 30. The arithmetic unit 30 Fourier-transforms the input signals from the AZD converters 14-1, 1, -2, 14-3, 14-1, 4, 1-5, 14-16, respectively. Then, the input signals from the AZD converters 14-13, 1-4, 14-5, and 14-16 are subjected to Fourier transform, respectively, and the highest-intensity frequencies obtained are fI, f2, f, respectively. 3 and f4, the signal strengths corresponding to the frequencies fl and f2 from the signal obtained by Fourier transforming the input signal from the A / D converter 14-1 are I (f1) and I (f 2), and the signal strengths corresponding to the frequencies f 3 and f 4 from the signals obtained by Fourier transforming the input signal from the AZD converters 14 and 1 are defined as I (f 3) and I (f 4) . here,

I (f 1) and I (f 3) are irradiation lights of the same wavelength. Since the signal is a transmitted light intensity signal corresponding to the wavelength of 1), a natural logarithm operation is performed after multiplying the two, and I (f 2) and I (f 4) also have the same wavelength. Irradiation light

Since the transmitted light intensity signal corresponds to (the light of wavelength 2 from the light sources 1-2 and 1-4 in FIG. 15), natural logarithm calculation is performed after multiplying the two.

In the above, the case where two irradiation optical fibers and two condensing optical fibers are arranged on the circumference of a single circle has been described, but the irradiation optical fiber and the condensing optical fiber are further described below. An example of optical fiber arrangement when a large number of optical fibers are arranged will be described. FIG. 21 shows a first arrangement example in which a large number of irradiation optical fibers and light collecting optical fibers are arranged. In this arrangement example, three irradiating optical fibers and three concentrating optical fibers are arranged on each circumference of the double concentric circle, but the irradiating optical fiber and the concentrating optical fiber are arranged. By arranging more on each circumference, the measurement sensitivity for the deep part inside the subject (living body) can be increased. Furthermore, concentric circles in which the irradiation optical fiber and the condensing optical fiber are arranged are further multiplexed. It is needless to say that the measurement sensitivity at various depth positions in the subject (living body) can be enhanced by providing the information.

In Fig. 21, the irradiation optical fibers 8-1, 8-2, and 8-3 are arranged at regular intervals of 120 degrees on the circumference of the circle 50-1 outside the double concentric circle. The converging optical fins 10-1, 10-2, and 10-3 are located at positions opposite to the irradiation optical fibers 8-1, 8-2, and 8-3 on the same circumference. Each is arranged S. The irradiating optical fibers 8-4, 8-5, and 8-6 are arranged at regular intervals of 120 degrees on the circumference of the circle 50-2 inside the double concentric circle. The condensing optical fiber 10- is located at a position facing the irradiation optical fibers 8-4, 8-5, and 8-6 on the same circumference.

4, 10-5 and 10-6 are arranged respectively. All (six) optical fibers are kept in the above-mentioned arrangement, and the same optical fiber holder as shown in Fig. 15

2 Fixed to 1 By adopting such an optical fiber arrangement, the transmitted light intensity detected on the circumference of the outer circle 50-1 is assigned as in-vivo deep part information. To calculate the change in hemoglobin concentration in the deep part of the living body, and assign the transmitted light intensity detected on the circumference of the inner circle 50-2 as shallow part information in the living body to perform the processing. This makes it possible to determine the change in hemoglobin concentration in the shallow part of the body.

Also, the hemoglobin concentration change obtained by multiplying the hemoglobin concentration change calculated from the transmitted light intensity detected on the circumference of the inner circle 50-2 by a predetermined weighting factor estimated from the sensitivity distribution. Is subtracted from the hemoglobin concentration change calculated from the transmitted light intensity detected on the circumference of the outer circle 50-1 to further improve the relative sensitivity of the deep part of the body to the shallow part of the body. It is also possible.

FIG. 22 shows a second arrangement example in which a large number of irradiation optical fibers and light collecting optical fibers are arranged. Here, an optical fiber arrangement that is more efficient when measuring at various measurement positions in a subject (living body) based on the present invention will be described. In this example, two pairs of one converging optical fiber for irradiation are arranged on the circumference of one circle as a basic fiber unit, and the basic fiber unit is set according to the desired measurement area size. Is provided in multiple units.

When the measurement area is extended with two pairs of irradiation-condensing optical fiber pairs arranged on the circumference of one circle as the basic fiber unit, as shown in Fig. 22, a square lattice An irradiation optical fiber and a condensing optical fiber are arranged on each of the lattice points, and the irradiation optical fiber and the condensing optical fiber are arranged alternately in the diagonal direction of the square lattice. Here, nine measurement positions are set, and nine circles 60-1 to 60-9 are set around each measurement position, and the irradiation optical fiber 8-1 to 8-8 and the condensing optical fiber 10-1 to 10-8 are arranged on the circumference of the circle and on the lattice points of the square lattice. With such an optical fiber arrangement, the irradiation optical fiber and the condensing optical fiber arranged on the intersection of the adjacent circles each have the number of circles intersecting at the lattice point where they are arranged (the number of circles intersecting at the lattice point where they are arranged). (4 at grid points) Since it functions with respect to the measurement position, measurement with a smaller number of optical fibers is possible. In this case, the force at nine measurement positions; ', it is easy to further increase the number of measurement positions (= number of circles, = number of grids) in order to perform measurement over a wider measurement area. From the measurement results obtained by widening the measurement region, an image of hemodynamics in a deep part in a living body can be obtained.

FIG. 23 shows a third arrangement configuration example in which a large number of irradiation optical fibers and condensing optical fibers are arranged. In this example, three pairs of irradiating and condensing optical fiber pairs are arranged on the circumference of one circle as the basic fiber unit, and the basic fiber unit is divided into multiple units according to the desired measurement area. Attached.

When the measurement area is extended using three optical fiber pairs for irradiation as one basic fiber unit on the circumference of one circle, as shown in Fig. 23, The irradiating optical fiber and the converging optical fiber are alternately arranged on each grid point of the rectangular lattice, and the irradiating optical fiber and the converging optical fiber are alternately positioned in the diagonal direction of each lattice. To Here, there are four measurement positions, and four circles 70-1 to 70-4 are set around each measurement position, and the irradiation optical fibers 8-1 to 8-8 and the condensing optical fiber 10-1 to 10-8 are arranged on the circumference of the circle and on the lattice points of the regular hexagonal lattice. With such an optical fiber arrangement, the irradiation optical fiber and the condensing optical fiber arranged on the intersection of the mutually adjacent circles have the number of intersecting circles (the lattice points inside the lattice) at the lattice points where they are arranged. In this case, it works for the same number of measurement positions as 3), so measurement with fewer optical fibers is possible. Although four measurement positions were used here, it is easy to further increase the number of measurement positions (= number of circles, = number of grids) in order to perform measurement over a wider measurement area. From the measurement results obtained by widening the measurement area, an image of hemodynamics in a deep part in a living body can be obtained.

Example 4>

FIG. 24 shows a fourth embodiment of the present invention suitable for measuring in-vivo deep information. A biological light measurement device will be described.

In this example, in order to measure changes in the concentration of oxidized and reduced hemoglobin in the subject (living body), light in an appropriate wavelength range is selected from white light, and the subject is irradiated with the light, and transmitted from the subject. A method of detecting transmitted light of two different wavelengths required for measurement by spectroscopy of light with a spectroscope is adopted.In addition, the light irradiation position and the light detection position on the subject are set at two cylinders each. However, it is easy to further increase the number (the number of wavelengths) of these irradiation lights, light irradiation positions, and light detection positions. In addition, by increasing the number of irradiation light (number of wavelengths), it is possible to measure the change in the concentration of light absorbing substances in other living bodies such as cytochrome and myoglobin in addition to the change in the concentration of oxidized and reduced hemoglobin. it can.

In Fig. 24, white light (light having a continuous wavelength spectrum) output from white light sources 80-1 and 80-2 passes through glass filters 84-1 and 84-2, respectively, for measurement. After being converted to light in the required wavelength range, they are introduced into the irradiation optical fibers 8-1 and 8-2 via the lenses 85-1 and 85-2, respectively, and transmitted to the subject (living body). 9 is irradiated. Here, the wavelength of the light irradiating the subject (living body) 9 is set within a range of 400 to 2400 nm. In particular, when measuring hemodynamics during vacation, the wavelength of the irradiated light is 7 ° ◦ππ! It is desirable to select the glass filters 84-1, 84-2 so as to be within the range of 1 to 100 nm. Also, output light from the light sources 80-1 and 80-2 are modulated by the light source driving circuits 4-1 and 4-2, respectively, so that the modulation frequencies f 1 and f 2 different from 100 Hz to 10 MHz are different from each other. Are intensity-modulated. On the other hand, the modulating frequency signals A and B from the light source driving circuits 4-1 and 4-2 are applied to the phase detectors 27-I and 27--2, 27--3 and 27--4 as reference frequency signals, respectively. Has been entered. The irradiation optical fibers 8-1 and 8-2 are fixed to the optical fiber holder 21 together with the condensing optical fibers 10-1 and 10-2 and are in contact with the surface of the subject 9.

The subject 9 is irradiated with light from the irradiation optical fibers 8-1 and 8-2, and the converging optical fiber is irradiated. The light transmitted through the subject 9 (transmitted light) at the optical fibers 10-1 and 10-2 is collected. Here, the irradiation optical fibers 8-1 and 8-2 and the condensing optical fibers 10-1 and 10-2 are arranged on the circumference of one circle set on the optical fiber holder 21. The optical fibers 10-1 and 10-2 are located alternately at intervals and are opposite to the optical fibers 8-1 and 8-2 for irradiation with the center of the circle interposed therebetween. Are set to be located respectively.

The light transmitted through the subject (living body) condensed by the condensing optical fibers 10-1 and 10-2 is guided to the spectrometers 86-1 and 86-2, respectively, and separated (wavelength separated). You. In the spectrometers 86-1 and 86-2, only component light having the wavelengths λ 1 and λ 2 required for measurement are selected from the component light of various wavelengths that have been separated. The transmitted light components at wavelengths λ 1 and λ 2 from the spectrometer 86-1 are transmitted by the photodetectors 11-1 and 11-12, respectively, and transmitted at wavelengths 1 and λ 2 from the spectrometer 86-1 and 2. The light components are detected (photoelectric conversion and amplification) by the photodetectors 11-3 and 11-4, respectively. A photomultiplier tube or an avalanche photodiode is used as the photodetector 11-1 to 11-14. Output signals (transmitted light intensity signals) from the photodetectors 11 1 to 11 to 11 are input to the phase detectors 27-1 to 27-4, respectively.

The signals input to each phase detector are mixed with transmitted light intensity signals having the same wavelength but different modulation frequencies, but the phase detectors 27-1 and 2-7-2, 2 Since the reference frequency signals A and B having the frequencies fl and f2 from the light source drive circuits 4-1 and 4-2 are input to 7-3 and 27-4, respectively, the phase detector 2 7 1 1 In the phase detector 271-2, only the transmitted light intensity component corresponding to the irradiating light of wavelength 1 from the irradiating optical fiber 8-1 is applied to the irradiating light of wavelength λ2 from the irradiating optical fiber 8-1. In the phase detector 27-3, only the corresponding transmitted light intensity component is transmitted. Only the transmitted light intensity component corresponding to the irradiation light of wavelength 1 from the irradiation optical fiber 8-2 is output to the phase detector 27-3. In Fig. 4, only the transmitted light intensity component corresponding to the irradiation light of wavelength 2 from the irradiation optical fiber 8-2 is selectively separated. It is output Te. Both output signals from the phase detectors 27-1 and 27-3 (wavelengths from the irradiation optical fibers 8-1 and 8-2; intensity signals transmitted through the living body based on L 1 irradiation light) are multipliers. 2 8—1 is input and multiplied by each other, and both output signals from the phase detectors 2 7—2 and 2 7—4 (to the irradiation light of wavelength λ 2 from the irradiation optical fibers 8—1 and 8—2) Is transmitted to the multiplier 28-2 and multiplied by each other. The output signals from the multipliers 28-1 and 28-2 are input to log amplifiers 29-1 and 29-12, respectively, and are naturally logarithmically amplified. Further, the log amplifiers 29-1 and 29-2 Are input to the AZD converters 14-11 and 14-12, respectively, are converted into digital signals, and then are taken into the arithmetic unit 30.

In the arithmetic unit 30, the change in oxyhemoglobin concentration, the change in reduced hemoglobin concentration, and the change in oxidized hemoglobin concentration and the change in reduced hemoglobin concentration, which indicate blood volume, are obtained from the time-series signals of the transmitted light intensities of the two wavelengths taken in. (Total hemoglobin concentration change) is calculated, and the calculation result is displayed on the display device 17 as a time-series change graph.

In Embodiment 3 (FIG. 15) and Embodiment 4 (FIG. 24) described above, an example is shown in which the optical fiber holder 1 is provided with two pairs of light-collecting optical fibers for irradiation. By increasing the number of irradiating and condensing optical fiber pairs provided in the fiber holder 21 to a greater number, the measurement sensitivity in the deep part inside the subject (living body) can be dramatically increased. For example, in the device configuration shown in Fig. 24, the measurement results obtained when four pairs of irradiating optical fibers were provided in the outgoing fiber holder 21 are shown in Figs. 25, 26, and 27. Show. Assuming that the surface of the subject (living body) is a plane, a plane parallel to the living body surface is defined as an X-— plane, and the center is x = 32.5 mm and y = 32.5 on the living body surface. A circle with a diameter of 30 mm at the position of mm is set, and four irradiation optical fibers and four focusing optical fibers are alternately set on the circumference of the circle, and the center of each circle is set. The results of measurement using four pairs of one light-collecting optical fiber pair consisting of an irradiation optical fiber and a condensing optical fiber that are point-symmetrical to each other as the center of point symmetry The relative sensitivity distribution at a depth of 2.5 mm (Fig. 25), the relative sensitivity distribution at a depth of 7.5 mm in the living body (Fig. 26), and a depth of 12.5 mm in the living body This is shown as the relative sensitivity distribution at the position (Fig. 27). As is clear from the comparison between the measurement results of the conventional example (FIGS. 12 to 14) and the measurement results of the present invention (FIGS. 25 to 27), according to the present invention, in vivo The measurement sensitivity in the deep part can be remarkably improved.

In the present embodiment, the transmitted light in the subject of a plurality of wavelengths emitted from a plurality of light irradiation positions on a predetermined circle interposes the center of the circle with each of the plurality of light irradiation positions on the circle. In the above, a configuration example was shown in which detection was performed at a plurality of light collection positions set at point-symmetric relational positions, and the intensity of transmitted light detected at these plurality of light collection positions was all multiplied for each same wavelength. Similarly, a device configuration in which all additions are performed for each of the same wavelengths has a reduced physical meaning, but it is possible to improve the relative sensitivity of a deep part in a subject (living body). Further, the measurement sensitivity of the target measurement area may be improved by using an apparatus configuration that performs four arithmetic operations on the transmitted light intensity in the subject (living body) detected at a plurality of light condensing positions.

ADVANTAGE OF THE INVENTION According to this invention, the light absorption substance density | concentration in the area | region of predetermined depth in a test object (living body) can be measured with high precision. An example of a measurement that requires sufficient measurement sensitivity deep inside the subject (living body) is, for example, measurement of changes in hemodynamics due to cerebral function activity. Force according to the present invention ^ According to the present invention, Hemodynamic changes can be measured from above the scalp.

《Biometric input device and biological control device》

Further, according to the present invention, as described above, a living body light measuring device capable of measuring biological information with respect to a wide spatial region within a subject (living body) with high efficiency, high accuracy, and high spatial resolution can be realized. Therefore, by using the measurement signal from the biological optical measurement device directly as an input signal of various external devices, a highly practical biological input device and a biological device capable of controlling these various external devices quickly and with high accuracy. A control device can be realized. Various input devices such as a keyboard, a mouse, and a steering wheel are used to operate devices such as a computer and a game machine. However, such input devices operated by humans with limbs reduce the sense of presence in game machines, for example, or make it difficult for persons with physical disabilities to operate. Therefore, a device for performing direct input from the brain using brain waves has been proposed, for example, in Japanese Patent Application Laid-Open No. 7-124331. This device attempts to control a computer, especially a game machine, by inputting brain waves directly to the computer, such as when measuring an electrocardiogram.

Such a direct input device from the brain facilitates the control of external devices even for persons with impaired motor function, and is expected to contribute to the social participation of physically handicapped persons. .

By the way, as shown by the Broadman brain map, the human brain is divided into regions with different cell structures, and each region has a different function. For example, when the brain is viewed from the side, the area involved in spontaneous movements (hands, fingers, feet, etc.) is at the top, the area involved in sensation and vision is the occipital area, and the area involved in language is the left half. It is located in the designated part.

As described above, in order to extract information from a specific region in the brain with high accuracy, it is necessary to use a measuring device with high spatial resolution. However, since the electroencephalogram used in the above-described conventional technology has an inhomogeneous dielectric constant in a living body, the location where a signal (electroencephalogram) is generated is unclear, so that measurement with high spatial resolution is difficult. In addition, there is also a constraint that the movement of the subject must be constrained during the measurement because the myoelectric potential generated when the subject moves greatly reflects on the electroencephalogram measurement signal and adversely affects the measurement result. Therefore, there is a problem in accuracy and practicability in the method of using brain waves directly as a direct input signal from the brain.

According to the present invention, as described above, a living body optical measurement device capable of measuring biological information in a wide spatial region within a subject (living body) with high efficiency, high accuracy, and high spatial resolution can be realized. Directly input measurement signals from optical measurement devices to various external devices By using the signal as a signal, it is possible to provide a highly practical biological input device and a biological control device capable of controlling these various external devices quickly and with high accuracy. The living body input device using the living body light measurement method according to the present invention comprises: a light irradiating means for irradiating light from outside the scalp of the human head into the brain; and irradiating the light into the brain by the light irradiating means. Light collecting means for collecting the light passing through the brain by the light collecting means; light measuring means for measuring the intensity of the light passing through the brain collected by the light collecting means; and the light measuring means From the intensity of the light passing through the brain measured by the above, the oxyhemoglobin concentration change value, the reduced hemoglobin concentration change value, or the total hemoglobin concentration change value in a predetermined region in the brain is calculated and further calculated. Calculating means for calculating a desired characteristic parameter value from the hemoglobin concentration change value obtained as described above, and determining and outputting the type of output signal based on the calculated characteristic parameter value; and Equipped with It becomes Te.

The biological input device may further include, as reference data for the characteristic parameter value, a change rate of the hemoglobin concentration at an arbitrary time interval, an intensity of the time change of the hemoglobin concentration at an arbitrary frequency, which is to be calculated by the arithmetic means, and the like. It may include storage means for setting and storing in advance. In this case, the calculating means determines the type of the output signal from the characteristic parameter value obtained by the above calculation and the reference data stored in the storage means and outputs it.

In addition, the biological control device using the optical biological measurement method according to the present invention includes the biological input device, and an output signal determined by the biological input device as an input signal, and a predetermined functional operation according to the type of the input signal. And an external device for performing the following.

The light condensed by the above-mentioned condensing means is a force classified into reflected light and transmitted light in a living body (brain). In the present invention, both of these are transmitted light (transmitted light). . In the present invention, brain function activity localized in a living body (brain) is measured using light, and this measurement signal is used as an input signal to an external device such as a computer. That is, the irradiation optical fiber and the condensing optical fiber are connected to a desired measurement area in the brain (for example, (Right finger motor area, left finger motor area, language area, etc.) at the position on the head surface, irradiate light into the brain, collect and measure the light passing through the brain, and measure this signal. Is input to the arithmetic unit. In the arithmetic unit, the cursor is moved to the left for signals from the right finger motor area, for example, the cursor is moved to the right for signals from the left finger motor area, On the other hand, the type of output signal for performing a click operation or the like is determined, and the output signal is input to an external device such as a computer, a word processor, or a game machine. The external device performs an operation according to the type of the input signal.

In another calculation example of the arithmetic unit E, a change in the oxidized hemoglobin concentration, a change in the reduced hemoglobin concentration, or a change in the total hemoglobin concentration in the brain is calculated from the measured intensity of the light passing through the brain. The type of the output signal is determined by comparing the calculated characteristic parameter value with the calculated characteristic parameter value and the characteristic parameter value (reference data) previously stored in the storage device. Input the output signal to the external device.

Furthermore, in other calculation examples, the operation content such as “cursor right”, “force cursor left”, “click”, etc., does not correspond to the specific measurement area for each input signal to the external device. The operator remembers the standard deviation value and average value for each feature parameter in each measurement area at that time as learning data in the storage device, and compares the actual measurement value with those learning data. Then, if they match within the allowable range, a signal instructing execution of the operation content corresponding to the learning data is output. In this way, the Mahalanobis distance can be used to determine the type of output signal using the feature parameters, and a neural network can also be used. Here, the Mahalanobis distance is an index for determining whether an actual measurement value belongs to the distribution when the measurement value or the like is represented by a normal distribution having a variance.

With these methods, it is possible to directly control computers, processors, game machines, etc. without using a keyboard or mouse. Also available.

Furthermore, by arranging light irradiating means and condensing means at a number of points on the surface of the subject (living body), the driver's dozing alarm device, environmental control device, learning degree determination device, sick person, infant, animal, etc. It can also be applied to an intention display device, an information transmission device, or a lie detector.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Example 5>

FIG. 28 shows a schematic configuration of a brain function activity measuring device used in the biological input device according to the fifth embodiment of the present invention.

In the present embodiment, the localized brain function activity is measured using light, and the resulting signal is used as an input signal to a computer or an external device.

The purpose of this study was to measure changes in oxidized hemoglobin concentration and reduced hemoglobin concentration in the brain.Using two different wavelengths of irradiation light, the changes in oxidized hemoglobin concentration and reduced hemoglobin concentration were independent. To measure. That is, using the difference in color (difference in light absorption wavelength) between oxyhemoglobin and reduced hemoglobin, the oxyhemoglobin concentration and the reduced hemoglobin concentration are measured separately. If the number of wavelengths of the irradiation light is further increased, the measurement accuracy will be further improved, and the concentration of substances other than oxidized and reduced hemoglobin can be measured. Here, the case where the light irradiation position and the light detection position are each set to one position will be described. However, it is easy to expand the measurement area by increasing the number of each.

In Fig. 28, light beams with specific wavelengths 1 and 2 are output from light sources 1-1 and 1-2, respectively, and introduced into optical fibers 2-1 and 2-2, respectively. Here, the wavelengths 1 and λ 2 of the output light from the light sources 1-1 and 1-2 are respectively selected from the wavelength range of 400 nm to 240 nm. In particular, when measuring hemodynamics in a living body, the measurement accuracy is selected from within the wavelength range of 700 nm to 110 nm so that the wavelength difference between them is within 50 nm. Desirable to raise. In other words, this wavelength In the region, light transmission in the living body is high. At longer wavelengths, light absorption by moisture increases, and at shorter wavelengths, hemoglobin itself also increases light absorption, which is not convenient. The output lights from the light sources 111 and 112 are intensity-modulated by the drive circuits 411 and 4-2 at different modulation frequencies f1 and f2, respectively. In addition, the modulation frequency signals A and B from the drive circuits 4-1 and 4-2 are input to the phase detectors 27-1 and 27-2, respectively, as reference frequency signals. This is to separate and extract each signal component from the detection signal in which the signal component corresponding to the oxidized hemoglobin concentration value and the signal component corresponding to the reduced hemoglobin concentration value are mixed.

The optical fibers 2-1 and 2-2 are connected to the optical directional coupler 3-1. The light of wavelengths 1 and 2 from the light sources 111 and 〖-2 are mixed here for irradiation. Is introduced into the optical fiber 8-1, and transmitted to the surface of the subject (living body) 9.

Light is emitted from the irradiation optical fiber 8-1 into the subject (living body) 9, and the light passing through the living body is collected and detected by the collecting optical fiber 10-1. As a result, changes in the oxidized and reduced hemoglobin concentrations in blood can be measured as changes in the respective colors (changes in the light absorption wavelength). Oxygen saturation is high in arteries (the proportion of oxyhemoglobin occupied in total hemoglobin), but oxygen saturation is lower in veins than in arteries. Here, the distance between the irradiation optical fiber 8-1 and the light condensing optical fin 10-1 is in the range of 10 to 50 mm depending on the desired depth of the measurement area in the living body and the like. Is set to 30 mm in this embodiment.

The light passing through the living body condensed by the condensing optical fiber 10-1 is sent to the photodetector 11-1 where it is photoelectrically converted and amplified. Photomultipliers and avalanche photodiodes are used for the photodetectors. The output signal from the photodetector 11 is divided into two and then input to the phase detectors 27-1, 27-2. The signals input to the phase detectors 27-1 and 27-2 include the two wavelengths irradiated into the living body 9 from the irradiation optical fiber 8-1; corresponding to the light of I 1 and E 2, respectively. Living body The phase detector 27-2 27-2 receives the reference frequency signal from the drive circuits 41-1 and 42-2, respectively. In the detector 27-1, the intensity signal of the light passing through the living body corresponding to the irradiation light having the wavelength λ1 (modulation frequency f1) from the light source 1_i is obtained. In the phase detector 27-2, the light source 1 2, the intensity signal of the light passing through the living body corresponding to the irradiation light having the wavelength λ 2 (modulation frequency f 2) is separated and selected and output.

The in-vivo transmitted light intensity signals separated and selected by the phase detectors 27-1 and 27-2 are then input to the Λ / D converters 14 1 and 14-2, respectively. After being converted into a digital signal, it is taken into the arithmetic unit [130].

The arithmetic unit 3◦ calculates the oxyhemoglobin concentration, the reduced hemoglobin concentration, and the sum of the oxidized hemoglobin concentration and the reduced hemoglobin concentration representing the blood volume from the time-series signals of the transmitted light intensities at the two wavelengths. The calculation result is displayed on the display device 17 as a time-series change graph. The total amount (volume) of hemoglobin in the blood is constant, so simply adding the amount of oxidized hemoglobin and the amount of reduced hemoglobin gives the total blood *.

In the device configuration of the present embodiment, a method of calculating changes in oxyhemoglobin, reduced hemoglobin, and total hemoglobin concentration accompanying brain activity is described in, for example, a patent application by the present applicant (Japanese Patent Application No. Hei 7-309). 72 application) in the specification and drawings (arithmetic processing method). Although only the amount of change in hemoglobin concentration is calculated here, the absolute amount of hemoglobin concentration can be measured by performing calculation excluding the influence of light scattering in a living body.

FIG. 29 is a graph illustrating an example of a change in hemoglobin concentration during right finger movement measured using the brain function activity measurement device of this example. Here, the region in the brain (the right finger motor area) related to the movement of the right finger is used as the measurement region, and the changes in the oxyhemoglobin concentration (a), the reduced hemoglobin concentration (b), and The time series change of the total hemoglobin concentration change (c) is shown. Note that the time indicated by diagonal lines in the figure The area (T:) is the period during which the right finger exercises.

FIG. 30 is a graph showing an example of a change in hemoglobin concentration during left finger movement measured using the brain function activity measurement device of the present example. Here, the region in the brain related to the movement of the left finger (the left finger speed field) is used as the measurement region, and the change in oxyhemoglobin concentration (d), the change in reduced hemoglobin concentration (e), And changes in total hemoglobin concentration). The hatched time region (T ₂ ) in the figure is the exercise period of the left finger.

As is clear from a comparison between FIG. 29 and FIG. 30, the change in oxyhemoglobin concentration (a) and the change in total hemoglobin concentration (c) in the right finger motor area during the right finger movement period (Τ,) The change in oxygenated hemoglobin concentration (d) and the change in total hemoglobin concentration (f) in the left finger motor area during the finger movement period () are approximately three times as large. The motor area on the left side of the brain is the area involved in the movement of the right body, and the motor area on the right side of the brain is the area involved in the movement of the left body. The body parts involved are cross-related to each other. It should be noted from FIGS. 29 and 30 that the changes in reduced hemoglobin concentration (b) and (e) do not change so significantly. FIG. 31 is a contour graph showing an example of a change in total hemoglobin concentration during right finger movement measured by the brain function activity measuring device of the present embodiment. Here, measurement is performed at multiple points in the brain so as to encompass the right finger motor area, and the amount of change in the total hemoglobin concentration during right finger movement is shown as a contour graph. In Fig. 31, the vertical direction corresponds to the vertical direction of the brain, the left side corresponds to the front side of the brain, and the right side corresponds to the back side of the brain. From this figure, it can be seen that the brain function activity measuring device of the present embodiment can measure brain function activity at a local site in the brain showing such a remarkable change.

FIG. 32 is a contour graph showing an example of a change in the total hemoglobin concentration at the time of recalling a language measured by the brain function activity measuring device of the present embodiment. Here, measurements are made at multiple points in the brain so as to encompass the brain area (language area) involved in language activity, and the amount of change in oxidized hemoglobin concentration when words are recalled is shown in a contour graph. . The language field is It is located in the brain near the temple on the left side of the head. Also in this case, the brain function activity measuring apparatus of this embodiment measures the brain function activity at a local site in the brain showing a remarkable change. According to the brain function activity measuring device of the present embodiment, it is possible to measure such a language recall activity in the brain.

Therefore, in the present invention, a highly accurate and practical direct input method from the brain is realized by using a highly accurate measurement signal measured by the brain function activity measuring device as an input signal to an external device. Can be.

The outline of the basic configuration of the brain function activity measuring device used in the biological input device according to the present invention has been described above. Hereinafter, specific configuration examples of the biological input device and the biological control device of the present invention will be described.

FIG. 33 is a schematic configuration diagram of a biological control device according to a fifth embodiment of the present invention. In FIG. 33, the biological control device according to the present embodiment includes a biological input device 100 and an external device 200.

In the biological input device 100, the brain function activity measuring device 110 having the configuration shown in FIG. 28 is used to receive light through the irradiation optical fibers 8-1, 8-2, and 8-3. The specimen (human head) 9 is irradiated with light, and the transmitted light from the subject 9 is condensed by the condensing optical fibers 10-1, 10-2 and 10-3 to reduce the transmitted light intensity. measure. The irradiation and collection optical fibers are composed of a pair of irradiation optical fiber 8-1 and collection optical fiber 10-1 in the first measurement area, and a pair of irradiation optical fiber 8-2 and collection optical fiber 8-1. The pair of optical fibers 10 and 12 correspond to the second measurement region, and the pair of the irradiation optical fiber 8-3 and the collection optical fiber 10 and 13 correspond to the third measurement region, respectively. It is fixed to the helmet 21 for fixing the optical fiber. In addition, it is easy to further increase the number of measurement areas by increasing the number of pairs of optical fibers for one irradiation and condensing, and to improve the measurement accuracy (spatial resolution), each measurement area must have a plurality of measurement areas. It is also easy to arrange optical fiber pairs.

Passing light intensity for each measurement area measured by the brain function activity measurement device 110 Is input to the arithmetic unit 120. The arithmetic unit 120 receives the input transmitted light intensity for each measurement area, the light absorption coefficient of the oxidation and reduction hemo-mouth bottles stored in the storage device 130 in advance, and other arithmetic data. Then, an arithmetic operation according to an arithmetic method described later is performed, and a desired signal is specified and input to the external device 200. The storage device 130 stores in advance the results of the learning (light absorption coefficient and various calculation data) in order to determine the meaning of each signal. Is stored.

The external concealment 200 operates according to the type of the signal manually input from the arithmetic unit 120. Examples of the external device 200 include a computer, a word processor, a game machine, and a communication device.

Next, a calculation method in the calculation device 120 will be described.

FIG. 34 is a flowchart illustrating an example of a first calculation procedure in the calculation device 120. For example, a pair of the irradiation optical fiber 8-1 and the condensing optical fiber 10-1 is placed in the left finger motor area (measurement area 1), and the irradiation optical fiber 8-2 and the condensing optical fiber 10 0 — The pair of 2 and 3 correspond to the right finger motor area (measurement area 2), and the pair of irradiation optical fiber 8-3 and condensing optical fiber 10-3 correspond to the language area (measurement area 3). And the in-vivo light intensity in each measurement area is measured, and the measurement result is input to the arithmetic unit 120.

(s t e p 1-1)

Calculate the concentration value of oxidation, reduction, or total hemoglobin from the transmitted light intensity of each wavelength from the measurement area 1.

(s t e 1-2)

Calculate the characteristic parameter values from each or any of the hemoglobin concentration values calculated in step 1-1, ie, the oxidation, reduction and total hemoglobin concentration values or any one of them. . The characteristic parameters include, for example, the integrated value of each or any hemoglobin concentration at an arbitrary time interval, The rate of change of the hemoglobin concentration and the intensity of the arbitrary frequency of the time change of each or any hemoglobin concentration are used, and these can be variously determined.

I s t e p 1— 3)

The feature parameter value calculated in step 1-2 is compared with the learning value stored in the storage device 130 to determine whether or not the feature parameter value is within a predetermined threshold range. Is determined, and if it is within the range (yes), the output is Nobuy · 1 ₍ , and if it is outside the range (η 0), the process proceeds to ste ρ 14.

(s t e p 1— 4)

Calculate the concentration value of oxidation, reduction, or total hemoglobin from the transmitted light intensity of each wavelength from measurement area 2.

(s t e p 1-5)

s 1 e p Calculates the characteristic parameter value from each or any hemoglobin concentration value calculated in 1-4 and obtains it. The characteristic parameters include, for example, an integrated value of each or any hemoglobin concentration at an arbitrary time interval, a change rate of each or any hemoglobin concentration at an arbitrary time, and a time of each or any hemoglobin concentration. The intensity at any frequency of change is used and these can be determined variously.

(s t e p 1-6)

It is determined whether or not the characteristic parameter value calculated by st e p 1-5 is within a predetermined threshold range. If the value is within the range (yes), signal 2 is output. If the value is out of the range (n 0), the process proceeds to st e p 1-7.

(s t e p 1— 7)

Calculate the concentration value of oxidation, reduction, or total hemoglobin from the transmitted light intensity of each wavelength from the measurement area 3.

(s t e p 1-8)

A characteristic parameter value is calculated from each or any hemoglobin concentration value calculated in step 1-7 to obtain a value. As the feature parameters, for example, arbitrary time intervals Of each or any hemoglobin concentration, the rate of change of each or any hemoglobin concentration at any time, and the intensity of the time change of each or any hemoglobin concentration at any frequency. Used, and these can be determined in various ways.

(st e 1 1 9)

Step 1 Feature parameter value calculated by 1-8 Determine whether it is within a predetermined threshold range, and if it is within the range (yes), output signal 3 _c If out of range (no), return to step 1-1.

Here, assuming that the external device 200 is a computer, the external device 200 is always kept in an input waiting state. In addition, move the cursor to the left for signal 1 input, move the cursor right for signal 2 input, and click for signal 3 input. It is also possible to make the response function of the device 200 correspond.

As an extended example of the above calculation method, in step 1-3, step 1-6 and step 1-19, a “0” signal is output when the signal is within the threshold range, and a “1” signal is output when the signal is outside the threshold value If it is output, eight combinations (0 00 to 11 1) can be made as signals output from the arithmetic unit 120. In this case, the arithmetic unit 120 may output signals 1 to 8, and the response function of the external device 200 corresponding to each output signal may be determined in advance.

In the above-described first example of the calculation procedure, the measurement areas are determined in advance as the right finger motor area, the left finger motor area, and the language area, and the measurement signal from each measurement area and the response function of the external device are one-to-one. I described the case where it was made to correspond to.

FIG. 35 is a flowchart showing a second example of the calculation procedure in the arithmetic unit 120. _c This second example of the calculation procedure is a measurement of the oxidation, reduction, or change in the concentration of total hemoglobin in each measurement region. This is the case where the value and the signal input to the external device 200 do not have a one-to-one correspondence. In the first example of the first calculation procedure, the predetermined measurement area (specific Signals from specific brain regions involved in functional movements) are selectively extracted, and this signal is associated one-to-one with the specific functional movements described above. If you have a willingness to move it, you must remind yourself to move your left hand accordingly, and the actual function of the external device and the intention of the operator may be far apart. . The second operation procedure example described below takes into consideration the above-mentioned problems in the first operation procedure example.

First, the measurement area is set at a plurality of arbitrary locations (i locations), an irradiation optical fiber and a condensing optical fiber are arranged in each measurement area, and the in-vivo light intensity in each measurement area is measured. The result is input to the arithmetic unit 120. In other words, in this example, the purpose is to target a predetermined specific measurement area (a specific brain area involved in a specific functional operation) and selectively measure signals from only these specific measurement areas. Instead, the measurement optical fiber pair is placed at arbitrary positions K on the surface of the subject (human head) without specifying the measurement area, and the operator connects to an external device (for example, a computer). Since the learning is performed by repeatedly measuring the change in the concentration of hemoglobin at these multiple positions accompanying the brain function activity when recalling the input operation, and the learning result is stored in the storage device 130 in advance. is there. Then, hemoglobin concentration and characteristic parameters are calculated and obtained from the actually measured signals, and it is searched whether or not there is a similar characteristic parameter in the data stored in the storage device 130. The signal to be input to the device is determined.

Hereinafter, this second calculation procedure example will be described in detail along the flow shown in FIG. 35.

(s t e p 2-1)

From the transmitted light intensity of each wavelength from each measurement area i, calculate the concentration of oxidation, reduction, or total hemoglobin by calculation.

(s t e p 2-2)

From each or any hemoglobin concentration calculated by step 2-1 _, The value P i, j (matrix value) of each feature parameter j for each measurement area i is calculated and obtained. Here, the characteristic parameter j is, for example, an integrated value of each or any hemoglobin concentration at any time interval, a change rate of each or any hemoglobin concentration at any time, or a time change of each or any hemoglobin concentration. The intensity at an arbitrary frequency is used, which can be determined variously.

(s t e p 2— 3)

Here, the types of signals output from the arithmetic unit 120 are set to k types. The storage device 130 stores learning data about general or individual operators in advance.

The learning data structure is a standard deviation value and an average value for each feature parameter j for each measurement area i having the same structure for each output signal k. That is, it is assumed that the probability variance of the feature parameters is a Gaussian distribution. The Gaussian function can be described by the standard deviation and the mean.

For example, assuming that the external device 200 is a computer, the cursor is set to move to the right when the signal k from the arithmetic device 12 ° is input to the computer in advance. In addition, the operator wears the brain function activity measuring device 110 and repeatedly remembers “moving the force sol right” a plurality of times in advance. At this time, a standard deviation value and an average value are calculated for each feature parameter j for each measurement area i to be measured. The obtained standard deviation value and average value for each feature parameter j for each measurement area i are stored in the storage device 130 as learning data of the signal k. In this step 23, the stored learning data Di, j, k are read into the arithmetic unit 120.

Figure 36 shows the data structure of the learning data Di, j, k. In Fig. 36, S represents the standard deviation value, A represents the average value, and the dotted line (·····) means omission. The measurement area i is set to n places, and the number of types of the characteristic parameter j is set to m. The Mahalanobis is used for each signal k using all stored learning data D i, j, k and the value P i, j of each characteristic parameter j for each measurement area i calculated by ste ρ 2-2. The distance MD k is calculated and found. This Mahalanobis distance is represented by a well-known simple equation.

(s t e p 2-5)

Search for the minimum Mahalanobis distance M D k (min) from the Mahalanobis distance M D k for each signal k calculated by s t e p 2 — 4. If the signal with the minimum value is selected from 1 to k signals, it will be the minimum Mahalanobis distance M D k (min). (s t e p 2-6)

It is determined whether the minimum Mahalanobis distance M D k (min) is within an arbitrary threshold range. If so, go to st e p 2—7. If the value is out of the range, the process returns to step 2-1.

(s t e p 2-7)

The signal k obtained as described above is output and sent to an external device (computer) 200.

The above-mentioned second example of the operation procedure is an application of the Mahalanobis estimation method, but there is also a method of applying a neural network as a third operation method in order to perform a similar estimation. In this case, each characteristic parameter j for each measurement area i is input to each input terminal of the neural network, and each signal k (k = l to l) is assigned to each output terminal. The neural network learns in advance by each operator or a plurality of operations by a general operator so as to output an arbitrary signal k according to the value of each feature parameter j for each measurement area i. By using the learned neural network, the same function as that obtained by the Mahalanobis estimation shown in Fig. 35 can be obtained, and a signal corresponding to the user's recall can be output.

In FIG. 33, a neural network is connected to the subsequent stage of the arithmetic unit 120, characteristic parameters are input to input terminals of the network, and output terminals of the network are connected to the external device 200. In addition to the first, second, and third arithmetic methods described above, the arithmetic device determines the type of output signal by directly using the signal measured by the detector for measuring brain function activity. It is of course possible to do so.

Example 6>

FIG. 37 shows a schematic configuration of a biological control device according to a sixth embodiment of the present invention. This embodiment is an example in which a signal from the brain function activity measuring device according to the present invention is used to give a drowsiness warning to a car driver.

In Figure 37, 9 is the driver (subject), 102 is the steering wheel, 103 is the seat, 104 is the car, 105 is the driving circuit, 106 is the speaker, and 107 is the light. Fiber fixing device or helmet for fixing optical fiber, 108 is optical fino for light irradiation, ', 109 is optical fiber for condensing light, 111 is input device, and 112 is biological light measurement Unit (brain function measurement device), 113 is an input signal judgment unit, 114 is a signal line, 115 is a microcomputer, and 116 is a storage device. In the present embodiment, a drowsiness warning is issued to the driver 9 using the living body measurement signal from the living body light measuring unit 112. That is, the input device 1 1 1 (biological light measuring unit 1 1 2, input signal judging unit 1 1 3, light irradiating optical fiber 108, light condensing optical fiber 109, and light (Including a fiber fixing device or an optical fiber fixing helmet 107) Force A living body input device according to the present invention is constituted, and a microcomputer 115 is used as an external device. FIG. 37 shows a state in which the driver 9 is driving the automobile 104 by operating the steering wheel 102 while sitting in the seat 103. Driver 9 wears an optical fiber fixing device (Hellmet) 107. One or more pairs of light irradiation optical fibers 108 and light condensing optical fibers 109 are fixed to this optical fiber fixing device (helmet) 107. Light is constantly radiated to the head of the driver 9 from the optical fiber for light irradiation 108, and the light is fixed to a condensing position at an arbitrary distance (for example, about 30 mm) from the light irradiation position. The light passing through the living body is collected by the light collecting optical fiber 109. The light source of the light emitted from the optical fiber for light irradiation 108 is installed in the biological light measurement unit 112. Also, a photodetector for detecting the light condensed by the light condensing optical fiber 109 is provided in the biological light measurement unit 112 similarly.

Here, as shown in the embodiment of FIG. 33, modulation at different modulation frequencies is given to each irradiation light intensity for each different light irradiation position and each different irradiation light wavelength, and the light detectors use If the detected in-vivo transmitted light intensity signal is phase-detected and the transmitted light intensity components for each modulation frequency are separated and measured, the effect of stray light from other than the desired measurement position can be removed, It is possible to separate and measure the in-vivo light intensity components for each wavelength at each measurement position. The measurement position defined by a pair of optical fins for irradiating light, '108, and optical fins for condensing light 109, can be set to any arbitrary number of positions for each driver 9. If characteristic regions such as the frontal region with high permeability and the region where hemodynamics are significantly changed by drowsiness are known in advance, the measurement position is selectively set to these characteristic regions. Is good.

A drowsiness signal is extracted in the input signal determination unit 113 based on the measurement signal indicating the blood circulation of the head measured by the living body light measurement unit 112. Here, the input signal determination unit 112 includes a storage device that stores constant data necessary for hemodynamic calculation such as optical parameters such as hemoglobin and learning data on the driver 9, and calculates hemodynamics. And an arithmetic unit for determining the input signal. Further, as shown in the third example of the operation procedure, it is also possible to use a neural network to determine the input signal.

Here, if the drowsiness of the driver 9 is detected by the input signal determination unit 113, this sleepiness detection output signal is input to the microcomputer 115 via the signal line 114, and the microcomputer 1 From 15, a signal is sent to the drowsy alarm system consisting of the drive circuit 105 and the speaker 106 to issue an alarm. When this alarm command signal is input, the drowsiness alarm system sends an alarm sound signal from the drive circuit 105 to the speaker 106 to generate an alarm sound. Here, as the alarm means of the drowsiness alarm system, in addition to the above-mentioned sound stimulating means for the driver, a light stimulating means or a seat stimulating means Various means, such as one that vibrates 103, can be considered. Also, from the microcomputer 115, the voice signal data stored in the storage device 116 is selected according to the alarm level, and for example, “Danger! , Danger! , · · ·] Can be output as an audio alert indicating the content of the alert. Further, it is also possible to install the input device 111 in the optical fiber fixing device 107 and send a signal to the dozing alarm system by electromagnetic waves without using the signal line 114. In addition, if the microcomputer 115 determines that the alarm level has risen, the microcomputer 115, for example, applies a brake or stops the engine as indicated by a downward arrow. Can be directly output.

The alarm generation method using such a biological measurement signal can be applied not only to the driving of a car shown in Fig. 37 but also to the driving of all means of transportation such as an airplane and a train. The system can be applied as a device that automatically determines the drowsiness, fatigue, annoyance, redout, blackout, and other sensational conditions that may interfere with driving while the vehicle is operating. Note that redout and blackout are symptoms in which blood flow in the brain concentrates locally due to large acceleration during operation of an airplane or the like, causing visual abnormalities and loss of consciousness.

Thus, by using the biological input device according to the present invention as an input device to a microcomputer, it can be applied, for example, as an environment control device. In other words, it is used as a device that can judge the subjective sensation state of the environment such as cold, hot, relaxed, etc., and control the environmental conditions such as environmental temperature, environmental music, brightness, and image state. be able to.

It can also be applied as a learning degree determination device. That is, it can be used as a device that determines the degree of learning in learning, exercise (including rehabilitation), etc., and displays the proficiency. Further, based on the displayed proficiency, the trainee can be used as a training device for performing repetitive training.

It can also be applied as a diagnostic and alarm device in medical treatment. That is, epilepsy It can be applied to diagnostic devices for determining epileptic focus in patients, brain function testing devices for brain disease patients, and alarm devices for epileptic seizures.

In addition, the present invention can be applied as a device for displaying sensations and thoughts of those who cannot communicate their intentions to the outside such as patients, infants, animals, etc. with muscular diseases or vegetative states, or who originally cannot communicate. More specifically, an infant captures what he or she thinks, converts it into a digital electric signal, inputs it to a microcomputer, and registers meaningful words in memory beforehand. Select it and output it by voice. In addition, the information in the brain of the infant is captured by a biological input device, and changes in brain activity are detected every moment, and the changes are input to the speech synthesis circuit as phonemes, and the intention of the infant is conveyed as speech. Furthermore, by attaching the living body input device according to the present invention to animals, pets, and the like, it is possible to know what these animals want.

Also, the present invention can be applied to a device that determines emotions such as emotions and emotions and transmits emotion information by videophone or the like. An expression can be added to the computer graphics image of the sender's face displayed on the receiver side from the sender's emotion information transmitted by this device.

Also, the present invention can be applied to a device that determines the concentration and displays the same. Furthermore, it can also be applied to a lie detector.

As described above, according to the present invention, localized brain function information is measured by a brain function measurement device, and this measurement signal is used as an input signal to an external device. In addition to being able to control external devices without using a steering wheel, a vehicle alarm device, an environmental control device, a learning level determination device, a medical diagnostic and alarm device, a willingness display device, an information transmission device, It can also be applied to force judgment devices and lie detectors. Therefore, communication between persons who do not have the information transmission means, which has not been possible in the past, becomes possible. Industrial applicability

As described in detail above, the biological optical measurement device according to the present invention can be directly used as a device for measuring in-vivo information for medical use or the like, and indirectly, based on the measured in-vivo information. It can be used as a control device to activate an alarm device, a braking device, etc. of an automobile.

Claims

The scope of the claims

1. Light irradiating means for simultaneously irradiating a plurality of irradiation positions on the surface of the object with irradiation light having a wavelength in the visible to infrared region, and transmitting the light obtained by passing the irradiation light through the object to the object. A biological optical measurement device comprising: light detection means for simultaneously detecting at a plurality of detection positions on a surface; and imaging means for imaging information in a subject using detection signals from the light detection means. The light irradiation means includes light modulation means for intensity-modulating irradiation light to the plurality of irradiation positions at different modulation frequencies for each irradiation position, and the light detection means includes a plurality of detection positions. A biological light measurement device comprising selection detection means for selecting and detecting a passing light component having a different modulation frequency for each detection position from the passing light passing through the sensor.

2. Light irradiation means for simultaneously irradiating a plurality of irradiation positions on the surface of the object with irradiation light of a plurality of wavelengths in the visible to infrared region for each irradiation position, and the irradiation light is obtained by passing through the inside of the object. Light detecting means for simultaneously detecting the transmitted light at a plurality of detection positions on the surface of the object, and imaging means for imaging information in the object using the detection signal from the light detecting means. A biological light measuring device, wherein the light irradiation means includes light modulation means for intensity-modulating the irradiation light to the plurality of irradiation positions at different modulation frequencies for each irradiation position, and Means for selecting and detecting a passing light component having a different modulation frequency for each of the detection positions from the passing light to the plurality of detection positions. apparatus.

3. Light irradiating means for simultaneously irradiating a plurality of irradiation positions on the surface of the object with irradiation light of a plurality of wavelengths in the visible to infrared region for each irradiation position, and obtaining the irradiation light passing through the inside of the object. Light detecting means for simultaneously detecting the transmitted light at a plurality of detection positions on the surface of the object, and imaging means for imaging information in the object using the detection signal from the light detecting means. The light irradiation means includes a light modulation means for intensity-modulating the irradiation light to the plurality of irradiation positions at a different modulation frequency for each irradiation position and for each wavelength. The light detection means is adapted to detect the plurality of detection positions. A biological light measurement device comprising selection detection means for selecting and detecting a passing light component having a different modulation frequency for each detection position from the passing light.

4. The light irradiation means transmits and irradiates the irradiation light to the plurality of irradiation positions via light irradiation optical fibers provided correspondingly to each of the irradiation positions. Wherein the light detecting means transmits and detects the light passing through the plurality of detection positions via light detection optical fibers provided corresponding to each of the detection positions. The biological optical measurement device according to any one of claims 1 to 3.

5. The light irradiation unit includes a plurality of light sources that output irradiation light to the plurality of irradiation positions, and the light modulation unit converts output light from the plurality of light sources to different modulation frequencies. The method according to any one of claims 1 to 4, wherein the intensity of the irradiation light is modulated at different modulation frequencies. Biological light measurement device.

6. The biological optical measurement device according to claim 5, wherein the plurality of light sources are a plurality of semiconductor lasers.

7. The light modulating means modulates and drives the plurality of semiconductor lasers at different modulation frequencies to thereby intensity-modulate the irradiation light to the plurality of irradiation positions at different modulation frequencies. 7. The biological light measurement device according to claim 6, wherein:

8. The light irradiating means includes: a single light source that outputs irradiation light to the plurality of irradiation positions; and a light source for distributing and transmitting output light from the single light source to the plurality of irradiation positions. A plurality of light transmission paths, wherein the light modulating means modulates the intensity of the irradiation light distributed to the plurality of light transmission paths at different modulation frequencies, so that the plurality of light transmission paths are transmitted to the plurality of irradiation positions. The biological light measurement according to any one of claims 1 to 4, wherein the irradiation light is intensity-modulated at different modulation frequencies.

9. The light modulating means for modulating the intensity of the irradiation light distributed to the plurality of light transmission paths by using a liquid crystal filter or a light bulb. The biological light measurement device according to claim 1.

10. When a square grid is virtually set on the surface of the subject, the plurality of irradiation positions and the plurality of positions are set so that the irradiation of the irradiation light and the detection of the passing light are performed on the grid points of the square lattice. 10. The biological optical measurement device according to claim 1, wherein the detection positions are set and arranged.

11. The plurality of irradiation positions and the plurality of detection positions are alternately arranged on four grid points of each unit cell of the square grid, according to claim 10, wherein: Biological light measurement device.

12. When a regular hexagonal lattice is virtually set on the surface of the subject, the plurality of irradiation positions and the plurality of irradiation positions are set so that the irradiation of the irradiation light and the detection of the transmitted light are performed on the lattice points of the regular hexagonal lattice. 10. The biological optical measurement device according to claim 1, wherein a plurality of detection positions are arranged and set.

13. The plurality of irradiation positions and the plurality of detection positions are alternately arranged on six lattice points of each unit lattice of the regular hexagonal lattice. The biological light measurement device according to item [1].

14. An optical fiber for light irradiation for transmitting irradiation light to the plurality of irradiation positions on the subject surface and an optical fiber for light detection for transmitting the passing light to the plurality of detection positions are provided. The biophotometric device according to any one of claims 1 to 13, further comprising a measurement probe fixedly arranged in a predetermined positional relationship.

15. Light irradiating means for irradiating irradiation light having a wavelength in the visible to infrared region from the plurality of irradiation positions on the object surface to the inside of the object, and the object surface corresponding to each of the plurality of irradiation positions Light detecting means for selectively detecting the intensity of light transmitted through the subject from the irradiation position corresponding to each of the plurality of detection positions above; Means for calculating the transmitted light intensity in the subject of the irradiation light from the plurality of irradiation positions detected by the means, and from the plurality of irradiation positions to the corresponding detection positions, respectively. A biological light measurement device, wherein the plurality of irradiation positions and the plurality of detection positions are set such that the optical paths of transmitted light in the subject overlap with each other in a predetermined measurement region in the subject.

16. Irradiation light from each of the plurality of irradiation positions includes a plurality of wavelength components different from each other, and the light detection unit determines the intensity of the plurality of wavelength components transmitted through the subject for each wavelength. Claims characterized in that they are detected separately.

15. The biological light measurement device according to item 5.

17. The arithmetic processing means sets the measurement sensitivity of the biological information in the predetermined measurement area to be relatively higher than the measurement sensitivity of the biological information outside the predetermined measurement area. The biological light measurement device according to claim 15 or 16, wherein the internal transmitted light intensity is arithmetically processed.

18. The light irradiation means includes light modulation means for intensity-modulating the irradiation light, which irradiates the inside of the subject from the plurality of irradiation positions, with a different modulation frequency for each irradiation position. At each of the plurality of detection positions, selection detection means for selectively detecting the intensity of transmitted light in the subject having the same modulation frequency as the modulation frequency of the irradiation light from the irradiation position corresponding to the detection position. The biological optical measurement device according to claim 15, wherein:

19. Irradiation light from each of the plurality of irradiation positions includes a plurality of wavelength components different from each other, and the light irradiation means includes a plurality of wavelengths for irradiating the subject from the plurality of irradiation positions. Light modulating means for intensity-modulating the irradiation light containing the component at a different modulation frequency for each irradiation position and for each wavelength component, wherein the light detection means detects the light at each of the plurality of detection positions. The in-subject transmitted light intensity of a plurality of wavelength components having the same modulation frequency as the modulation frequency of each wavelength component of the irradiation light including the plurality of wavelength components from the irradiation position corresponding to the position is detected separately for each wavelength. Do 16. The living body light measuring device according to claim 15, wherein the living body light measuring device is a device.

20. first light irradiation means for irradiating the first irradiation light having a wavelength in the visible to infrared region from the first irradiation position on the surface of the object to the inside of the object, and the first irradiation light First light detection means for detecting light passing through the object at a first detection position on the surface of the object; and Second light irradiating means for irradiating the second irradiation light, and second light detecting means for detecting the light passing through the subject of the second irradiation light at a second detection position on the surface of the subject A biological light measurement device comprising: an arithmetic processing means for arithmetically processing the detection signals from the first and the first light detection means, wherein the biological light measurement apparatus moves from the first irradiation position to the first detection position. And the optical path of the first irradiation light passing through the subject and the second irradiation light from the second irradiation position to the second detection position. The first and second irradiation positions and the first and second detection positions are set so that the optical paths of the body-passing light overlap with each other in a predetermined region of the subject. Biological light measurement device.

2 1. Light irradiation means for irradiating the object with irradiation light containing a plurality of wavelength components from each of a plurality of irradiation positions on the subject surface, and a plurality of light irradiation means on the subject surface corresponding to the plurality of irradiation positions, respectively. Light detection means for selectively detecting the intensity of the transmitted light in the subject of the irradiation light from the irradiation position corresponding to the detection position at each of the detection positions, and detecting the intensity from the plurality of irradiation positions detected by the light detection means. Arithmetic processing means for arithmetically processing the intensity of the illuminating light transmitted through the subject; and calculating the intensity of the transmitted light within the subject from each of the plurality of irradiation positions to the detection position corresponding to the irradiation position. The plurality of irradiation positions, the plurality of detection positions, and the force position are set so that the optical paths overlap with each other in a predetermined measurement region in the subject. The arithmetic processing means is configured to detect the measurement sensitivity for the biological information in the predetermined measurement area with respect to the measurement sensitivity for the biological information outside the predetermined measurement area. Biological light measurement characterized by calculating the light intensity in the subject so as to increase relatively. apparatus.

22. The light irradiating means is configured to intensity-modulate the irradiating light including a plurality of wavelength components to irradiate the subject from the plurality of irradiating positions with a different modulation frequency for each irradiating position and each wavelength component. Light modulating means, wherein the light detecting means has, in each of the plurality of detection positions, an object having the same modulation frequency as the modulation frequency of the irradiation light from the irradiation position corresponding to the detection position. 22. The living body light measuring device according to claim 21, further comprising selection detecting means for selectively detecting the intensity of the transmitted light.

23. The biological optical measurement device according to claim 22, wherein the selection detection means includes a phase detection means.

24. The light detecting means according to claim 2, wherein the light detecting means includes spectroscopic means for separating the transmitted light in the subject to each of the plurality of detection positions for each of the plurality of wavelength components. 2. The biological light measurement device according to item 1.

25. When a square grid is virtually set on the surface of the subject, the plurality of irradiation positions and the plurality of the plurality of irradiation positions are set so that the irradiation of the irradiation light and the detection of the passing light are performed on the grid points of the square lattice. 26. The biological optical measurement device according to claim 21, wherein the detection positions are set.

26. When a regular hexagonal lattice is virtually set on the surface of the subject, the plurality of irradiation positions and the plurality of irradiation positions are set so that the irradiation of the irradiation light and the detection of the transmitted light are performed on the lattice points of the regular hexagonal lattice. The biological light measurement device according to any one of claims 21 to 24, wherein a plurality of detection positions are arranged and set.

27. The living body according to any one of claims 21 to 26, wherein the irradiation light is light in a wavelength range of 700 nm to 110 nm. Optical measuring device.

28. The biological light measurement device according to any one of claims 21 to 26, wherein the irradiation light is light having a wavelength near 805 nm.

2 9. The arithmetic processing means is provided in the subject detected by the light detecting means. 21. The method according to claim 21, wherein a change in the concentration of oxidized hemoglobin, a change in the concentration of reduced hemoglobin, and a change in the total hemoglobin concentration in the subject are calculated by calculating the transmitted light intensity. Biological light measurement device.

30. A display device for displaying a change in oxyhemoglobin concentration, a change in reduced hemoglobin concentration, and a change in total hemoglobin concentration over time obtained by the arithmetic processing means. Item 29. The biological photometric device according to item 29.

31. A plurality of irradiators for irradiating irradiation light of a plurality of wavelengths to a plurality of irradiation positions of the subject are provided, and the irradiation light irradiated for each of the irradiation positions is subjected to intensity modulation of a different modulation frequency for each wavelength A light irradiating unit having a modulating unit; and a plurality of condensing units for condensing transmitted light transmitted through the subject at a plurality of detection positions of the subject, the irradiating light emitted from each of the irradiating units. Condensing means having a plurality of condensing portions for condensing the transmitted light so that the respective optical paths of the transmitted light overlap each other; and a light converging section for each of the plurality of light irradiation positions and the plurality of wavelengths from the transmitted light. Light detecting means for detecting the light intensity of the transmitted light; detecting light having a predetermined intensity modulation frequency from the transmitted light, or detecting calculating the intensity of light having a predetermined intensity modulation frequency from the transmitted light Computing means, wherein the first predetermined Computing means for improving the sensitivity for detecting the optical parameters of the region or decreasing the sensitivity for detecting the optical parameters of the second predetermined region of the subject to calculate the intensity of the transmitted light. Biological light measurement characterized by having

32. Light irradiation means having a plurality of irradiation units for irradiating irradiation light of a plurality of wavelengths to a plurality of irradiation positions of the subject, and transmitting light transmitted through the subject at a plurality of detection positions of the subject. Focusing means having a plurality of focusing portions for focusing, detecting means for detecting the light intensity of the transmitted light, and improving sensitivity for detecting an optical parameter of a first predetermined region of the subject, Alternatively, there is provided an arithmetic processing means for arithmetically processing the intensity of the transmitted light by lowering the sensitivity for detecting an optical parameter in a second predetermined area of the subject. A biological light measurement device characterized by the above-mentioned.

33. The biological light measurement device according to claim 31 or 32, wherein the optical parameter is a light absorption coefficient.

34. Light irradiation means for irradiating the inside of the living body with light from at least one light irradiation position on the surface of the living body, and irradiation light from the light irradiation position at at least one light detection position on the surface of the living body. Light collecting means for collecting the light passing through the living body, light detecting means for detecting the intensity of the light passing through the living body collected by the light collecting means, and the light detected by the light detecting means. Computing means for determining and outputting the type of output signal based on the intensity of light passing through the body and reference data stored in advance, and storage means for storing the reference data A biological input device using a biological light measurement method characterized by the following.

35. Light irradiation means for irradiating the inside of the living body with light from at least one light irradiation position on the surface of the living body, and irradiation light from the light irradiation position at at least one light detection position on the surface of the living body. Light condensing means for condensing light passing through the living body, light detecting means for detecting the intensity of the light passing through the living body condensed by the light condensing means, and light condensing by the light detecting means. It has arithmetic means for determining and outputting the type of output signal based on the intensity of light passing through the body and reference data stored in advance, and storage means for storing the reference data. A living body control using a living body light measurement method, comprising: a living body input device; and an external device for executing a functional operation according to a type of the input signal using an output signal from the living body input device as an input signal. apparatus.

36. Light irradiation means for irradiating the inside of the living body with light from at least one light irradiation position on the surface of the living body, and irradiation light from the light irradiation position at at least one light detection position on the surface of the living body. Light condensing means for condensing light passing through the living body, light detecting means for detecting the intensity of the light passing through the living body condensed by the light condensing means, and light condensing by the light detecting means. Between light intensity passing through the body and reference data stored in advance Computing means for determining and outputting the type of output signal based on the input signal; storage means for storing the reference data; and an output signal from the computing means as an input signal corresponding to the type of the input signal. An external device for executing a functional operation, wherein the calculating means calculates the oxidized hemoglobin concentration at a desired measurement position in the living body based on the light passing through the living body measured by the light detecting means. Change value, reduction hemoglobin concentration change value or total hemoglobin concentration change value is calculated and obtained, and a desired characteristic parameter value is further calculated and calculated from the change value. The characteristic parameter value is stored in advance in the storage means. A biological control apparatus using a biological light measurement method, wherein the type of the output signal is determined and output based on the reference data.

37. The above characteristic parameter value is the integrated value of the oxidized hemoglobin concentration change value, the reduced hemoglobin concentration change value or the total hemoglobin concentration change value within the arbitrary measurement time, or the oxyhemoglobin within the arbitrary measurement time. Concentration change value, reduction hemoglobin concentration change value or average value of total hemoglobin concentration change value, or change value of oxidized hemoglobin concentration change value, reduction hemoglobin concentration change value or total hemoglobin concentration change value within the arbitrary measurement time The change rate of the oxidized hemoglobin concentration change value, the reduction hemog concentration concentration change value or the total hemoglobin concentration change value within an arbitrary frequency component or an arbitrary measurement time. 36. A biological control device using the biological optical measurement method according to item 6.

3 8. A light irradiation means for irradiating light into the brain of the vehicle driver from at least one light irradiation position on the head skin of the vehicle driver, and at least one light detection position on the head skin. A light collecting means for collecting the light passing through the brain of the irradiation light from the light irradiation position; a light detecting means for detecting the intensity of the light passing through the brain collected by the light collecting means; Calculating means for determining and outputting the type of output signal based on the intensity of light passing through the brain detected by the light detecting means and reference data stored in advance, and storing the reference data And a control signal for instructing execution of a functional operation according to the type of the input signal using the output signal from the arithmetic unit as an input signal. A microcomputer for generating the light, wherein the calculating means determines whether the driver is dozing from the intensity of light passing through the brain detected by the light detecting means and reference data stored in advance. If it is determined that the vehicle is in a dozing state, the microcomputer outputs a dozing state detection signal, and the microcomputer receives the dozing state detection signal from the arithmetic unit and prepares for the vehicle. A biological control apparatus for assisting a vehicle driver using a biological light measurement method, which generates a control signal for instructing operation of the obtained alarm generating device or brake device.