CA2045599C - Non-invasive measurement of blood glucose - Google Patents
Non-invasive measurement of blood glucoseInfo
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- CA2045599C CA2045599C CA002045599A CA2045599A CA2045599C CA 2045599 C CA2045599 C CA 2045599C CA 002045599 A CA002045599 A CA 002045599A CA 2045599 A CA2045599 A CA 2045599A CA 2045599 C CA2045599 C CA 2045599C
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Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
- A61B5/1455—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/359—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using near infrared light
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/0002—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network
- A61B5/0004—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network characterised by the type of physiological signal transmitted
- A61B5/0008—Temperature signals
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/14—Devices for taking samples of blood ; Measuring characteristics of blood in vivo, e.g. gas concentration within the blood, pH-value of blood
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
- A61B5/14532—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue for measuring glucose, e.g. by tissue impedance measurement
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/314—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry with comparison of measurements at specific and non-specific wavelengths
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3577—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing liquids, e.g. polluted water
Abstract
Near-infrared quantitative analysis instruments (100) and methods non-invasively measure blood glucose by analyzing near-infrared energy following interactance with venous or arterial blood, or transmission through a blood containing body part (F). The instruments and methods are accurate and readily lend themselves to at-home testing by diabetics.
Description
- - - 204~S99 NON-INVASIVE MEASUREMENT OF BLOOD GLUC~SE
Field of the Invention This invention relates to instruments and methods for the non-invasive quantitative measurement of blood glucose. More particularly, the invention relates to ~uch quantitative measurement via near-infrared interactance and transmittance.
Backqround of the Invention Information concerning the chemical composition of blood is widely used to assess the health characteri6tics of both people and animals. Blood analysi~ provides an indication of the current 6tatus of metabolism (e.g. glucose content) as well as level of ri~k a6sociated with certain ma~or illnesses (e.g.
risk of cardio-vascular disease as a function of cholesterol level). Blood analysis, by the detection of above or below normal levels of various substance~
also provides direct indication of the presence of many types of diseases and dysfunctions.
The normal method of determining blood chemi~try is by removing a sample of blood (e.g. 5-10 ml) and performing one or more standard chemical tests. These types of test~ are moderately expenslve, require one class of trained technicians to remove the blood and 2S another cla~s of trained technicians to perform the chemical tests. Moreover, the results of the blood - 204~99 "_ tests often are not available for several hours, and sometimes even several days.
Recently, an alternative type of technology (i.e.
~elf-contained in~truments) has been introduced for S relatively rapid blood ~creening of a large number of sub~ects. The~e instrument~, in general, use a much smaller blood sample (approximately .25 ml) from a "finger poke." This small blood sample is placed on a chemically-treated carrier and entered into the instrument. These instruments normally provide either an individual analyses (e.g. glucose level) or multiple analysis in a few moment~. These type~ of instrument~
unfortunately are quite co~tly, e.g., in the range of several thousand dollars.
A third clas~ of blood instrumentation i8 available for the specific purpose of determining glucose level in people with diabetes. This technology also uses a small sample from a finger poke and the sample is placed on a chemically treated carrier which is inserted into a portable battery operated instrument. In general, these instruments provide a single function; i.e. measurement of glucose. Although these specialized in~truments are relatively low cost ($300 or less iB typical), the cost of the di~posable carrier ~stick" must be considered. Since somQ
diabetic patients may require glucose analysis four or more time8 a day, the cost over a period of a year can become significant.
Current glucose analytical systems require blood to be extracted from the body prior to performing the analysis. Thi~ blood withdrawal requirement limits the application of such te~ting; many people who may be interested in knowing their glucose level are reluctant to have either their finger poked or blood samples - - 20g5~99 removed by hypodermic needle. This reluctance or anxiety in allowing blood sample removal i8 due to concern over the possibility of infection, discomfort (pain) and generalized patient fear.
Thus, there ifi a great need for non-invasive analytical instruments and methods that would provide essQntially the same accuracy as conventional blood glucose te~ts. Moreover, there is a need for a non-inva~ive low-cost method for measurement of glucose in diabetic patients.
Near-infrared ~sometimes referred to herein as simply "near-IR~) quantitative analysi~ is widely used in the field of agriculture for determining chemical compositions within grain, oilseeds, and other agricultural products. As an example, near-IR energy reflected from the surface of finely ground seeds and grain provides information concerning protein and moisturQ content. For a general introduction to near infrared quantitative analysis, see ~An Introduction to Near-Infrared Quantitative AnalysisU presented by Robert D. Rosenthal at the 1977 Annual Meeting of American Association of Cereal Chemlsts. Near-infrared technology has been extended to allow totally non-destructive measurements by using light transmission 2S through a sample as discussed in "Characteristics of Non-Destructive Near-Infrared Instruments for Grain and Food Products n by Robert D. Rosenthal, presented at the 1986 Meeting at the Japan Food Science InstitutQ.
Although this transmission approach avoids the need to finely grind the sample, it is not suited for use where access to two opposite surfaces is not available.
One example of this transmission approach is provided in V. S. Patent No. 4,621,643 (New, Jr. et al., 1986) relates to an optlcal oximeter apparatus for `~ - 20~599 determining pulse rate and degree of arterial oxygen saturation. Light energy iB passed through an appendage of the body, e.g. a finger, and strikes a detector positioned on a side of the appendàge opposite from the light source. Pulse rate and ~aturated oxygen are calculated from coefficients of extinction of light at the selected wavelengths.
Another approach to near-infrared quantitative analysis, using near-infrared interactance, was developed for non-invasively measuring body fat content. This approach i8 described in ~A New Approach for the Estimation of Body Composition2 Infrared Interactance", Joan M. Conway et al., The American Journal of Clinical Nutrition, 40~ Dec. 1984, pages 1123-1230. In thi~ non-invasive technique, a small optical probe that allows optical energy to enter the arm is placed on the biceps. The percent body fat of the entire body is dete~mined by measuring the spectrum change of the energy returned from an area ad~acent the light entry point.
SummarY of the Invention In accordance wlth the prQsent invention, a near-infrared quantitatiVQ analysis instrumQnt for measuring blood glucose compri~es means for introducing near-IR
energy into blood present in a body part of a sub~ect, means for detecting near-IR energy emerging from the sub~ect, means for converting an electrical signal corresponding to the detected energy into a readout indicative of the quantity of glucose present in the blood of the sub~ect, and mean~ for positioning the introducing means and detecting means ad~acent to the body part of the sub~ect.
20~ssss The pre~ent invention al~o provides methods for the near-infrared quantitative analysis of blood glucose, these methods including the steps of introducing near-IR energy into the blood within a body part of a sub~ect, detecting near-IR energy emerging from the sub~ect, the detector providing an electrical signal upon detecting said emerged energy, and processing the electricAl signal to provide a second signal indicative of the amount of glucose present in the blood. Some of thQse inventivQ methods utilize the principal of near-IR transmission while others utilize the principal of near-IR interaCtancQ.
In accordance with one aspect of the present invention, a near-infrared quantitative analysis in~trument for mea~uring blood gluco~e comprises means for introducing near-IR energy into blood present in a blood vessel, means for detecting near-IR energy following interactance of the same with thn blood, and means for position~ng the introducing means and detecting means over a blood vessel of the sub~ect.
This àspect of the invention further relates to methods wherein near-IR ener~y is introduced into a vein or artery of a sub~ect and interacts with blood glucose, the near-IR energy emerging from the sub~ect 25 i8 detected by a detector which provides an electrical signal, and the signal i~ processed to provide a readout indicative of the amount of glucose in the blood.
This aspect of the invention also relates to means and methodfi for marking a po~ition over a vein or artery of a sub~ect and then aligning a near-IR
analysis instrument with the markings to accurately position the instrument.
20~5~9 ~nother a~pect of the invention relates to an apparatus for measuring blood gluco~e via near-IR
transmission through a blood-containing body part, the apparatus including means for introducing near-IR
energy into one side of a body part, means for detecting near-IR energy emerging from an opposite side of the body part and means for positioning the near-IR
introducing and detecting means on opposite sides of the body part.
This a~pect of the invention also relates to methods for measuring blood glucose via near-IR
transmission including the steps of introducing near-IR
energy into one side of a blood-containing body part, detecting near-IR energy emerging from an opposite side of the body part and calculating blood glucose content.
~rief De3criPtion of the Drawinq~
FIG. 1 is a partially schematic elevational view of a near-infrared quantitative blood analysis instrument to which the present invention pertains.
FIGS. 2A and 2B are partially schematic elevational views of alternate embodiments of near-infrared quantitative analysis instruments.
FIG. 3 is an elevational view of a location device for use with the in6trument shown in FIG. 1.
2S FIG. 4 illustrates one embodiment for practicing the inventive method.
FIGS. SA and 5B illustrate two known configurations for interposing filters in a light path.
FIG. 6 i8 a plot of log (l/I) versus wavelength.
FIG. 7 illustrates a wavelength search study via a plot of correlation coefficient versus wavelength.
FIGS. 8 and 9 show plots of midpoint wavelength versu~ correlation coefficient for first derivative equations.
204~sg9 FIGS. 10 and 11 illustrate plots of correlation coefficient versu~ wavelength for second derivative equations.
Detailed DescriPtion of the Preferred Embodiments This invention uses the principle of light interactance to measure blood glucose level non-invasively by locating an optical transmitter snd a detector on the skin surface near either an artery or vein. Alternatively, the invention uses the principal of light transmi6sion through a portion of the body that has relatively uniform profusion of blood in order to measure non-inva~ively blood glucose.
In general, the arteries and veins of the human body are buried deep in the body to protect them from possible harm. However, in certain location~ of the body, the~e blood carrying vessels are close to the skin surface. This is particularly true for veins.
Some examples of such locations are at the crea~e of the elbow, the wrist, the back of the hand, and the bridge of the nose. Since the concentration of glucose is relatively constant in both the veins and arterie~, valid measurements can be obtained in either. However, because veins are generally closer to the skin's ~urface, they u~ually are the better candidate for non-invasive measurements.
The finger tip is another site particularly well suited for performing blood measurement~ with near-IR
light. The blood supply is distributed within the finger tip and, thus, ~mall variation~ in the placement _ 2~4S599 of a near-IR emitter or detector will not have a profound effect on the measurement re~ults.
According to one embodiment of the invention utilizing near-IR interactance analysis techniques, S near-IR light energy at bandwidths centering on one or more wavelengths of interest is passed through the skin and connective tissues and into a blood vessel of a sub~ect. A portion of the energy re-emerges from the blood vessel of the test sub~ect and is detected by a detQctor. Following amplification of the detector-genQratQd signal, the amplified output is processed into an output signal indicatinq the amount of glucose in the sub~ect's blood. The output signal drivQs a display device for providing a visual display of blood glucose content.
According to another embodiment of the invention utilizing near-IR transmission analysis techniques, near-IR light energy at bandwidths cent~ring on one or more wavelengths of interest is transmitted through a blood-containing portion of the body of a test sub~ect.
The near-IR energy emerges from the test sub~ect, opposite from the near-IR source, and is detected by a detector. Following amplification of the detector-generated signal, the amplified output is processed into an output fiignal indicating the amount of glucose in the sub~ect's blood.
In one embodiment utilizing near-IR interactance, the entire analytical instrument, including near-infrared source, transmitter, detector, amplifier, data processing circuitry and readout is contained within a lightweight hand-held unit. Infrared emitting diodes (IREDs) disposed in one chamber of the unit are focu~ed to transmit near-IR energy of preselected wavelength(s) to, e.g., a prominent vein of the wrist. The near-IR
23~599 energy interacts with the confitituents of the venous blood and is re-emitted from the vein. A detector housed within a second chamber of the unit is disposed along the vein a distance (1) from the emitter and S collects this energy. The detected signal is amplified and data proce~sed into a signal indicative of the amount of glucose in the blood. This signal is then fed to a readout device (preferably a digital readout) for recordation by a technician or direct analysis by a physician or the sub~ect himself.
Other near-IR apparatus, ~uch as the optical probe and associated instrumentation described in U.S. Patent No. 4,633,087 (Rosenthal), are useful in the practice of the present methods in which near-IR interactance is used to quantitatively measure blood glucose levels.
The present invention also includes a location device specially adapted to permit the user to locate the interactance instrument discussed above accurately along a vein. The location device permits the skin to be marked to ensure that repeated mQasurements are taken from the ~ame location, if desired.
A particularly preferred lightweight, hand-held interactance analysis instrument in accordance with the invention iB illustrated in Fig. 1. The instrument 10 includes one or more means for providing at least one point source of near-infrared energy of a predetermined half-power bandwidth centered on a wavelength of interest positioned within a first chamber 30 of the instrument 10. The near-infrared point source means are positioned 80 that near-infrared energy being emitted from the point source means will be focus~ed by lens 12 through window 14 and onto the ~kin of the test sub~ect. The near-infrared point source means may comprise one or a plurality of infrared emitting diodes 20~S~99 (IRED8). Two such IREDs 16 are visible in the embodiment illustrated in Fig. 1. In other embodiment employing a plurality of IREDs, three, four or more IRED~ may be utilized as the point source means.
In lieu of laborious characterization and sorting of each IRED, we prefer to provide narrow bandpass optical filters (as shown schematically in Fig. 1) between the infrared emitting diodes and the lens 12. A filter 23 is positioned between each IRED and lens 12 for filtering near infrared radiation exiting each IRED and thereby allowing a narrow band of near-infrared radiation of predetermined wavelength to pass through the filter and lens 12. Utilization of narrow bandpass optical filters provides for specific wavelength selection independent of the center wavelengths of the particular infrared emitting diodes being used.
Measurements can be taken inside the hslf power bandwidth of the IREDs, or alternatively, outside the half power bandwidth of the IRED~ a~ disclosed in commonly owned U.S. Patent No. 4,286,327. Figs. 5A and 5B illustrate two known configurations for interposing filters in a light path.
An optical detector, illustrated schematically and designated by reference numeral 28, is disposed within a lower end portion 42 of ~ ~econd chnmber 40 in case 20. Inner wall 22 is positioned between detector 28 and lens 12, thereby providing an optically-i~olating ma~k which prevents near infrared radiation from the point source mean~ and/or lens 12 from impinging directly on detector 28. Optical detector 28 generates an electrical signal when near-infrared radiation is detected.
The optical detector 28 i8 connected to the input of an electrical ~ignal amplifier 32 by suitable 1 1 2 a ~ ~ ~
electrical conducting means 33. Amplifier 32 may be an inexpensive integrated circuit (IC) signal amplifier, and amplifies the signals generated when near-IR energy strikes detector 28. The output of amplifier 32 is fed S to a data processor and display driver 34 which provides a signal to readout device 36. The readout dQvice 36 may have a digital display for directly displaying the amount of glucose present in the sub~Qct's blood.
The embodiment of Fig. 1 includes an optical filter 29 for shielding all but the desired near-IR
energy from detector 28. ~ilter 29 and window 14 are posit~oned for direct contact with the skin of the test sub~ect. An optically clear window can be employed in lieu of filter 29, if desired.
As noted earlier, this embodiment of the present invention utilizes the principal of near-IR
interactance for quantitative analysis. In interactance, light from a source is shielded by an opaque member from a detector 80 that only light that has interacted with the sub~ect is detected. Accurate measurements of the concentration of blood glucose can be made using many of the conventional algorithm~ used in near-IR quantitative analysis including those that have only a single variable term such as the following 2 APProximated First Derivative Alqorithm C = ~0 + Rl [log l/Ia - log l/I~]
APproximated Se~ond Derivati ve Alqorithm C = Ko + Rl [log l/I~ - 2~10g l/I~ + log l/Ic]
Normalized First Derivative Alqorithm llog l/Ia - log l~
C ' ~o + Kl [log l/II - log l/I~]
Normalized Second Oerivative Alqorit}un [log l/IA - 2~10g l/I~ + log ~ ]
C = Ro +
[log l/ID - 2~10g l/I~5 ~ log l/I~l where C denotes concentration of glucose present in the blood, Ro is the intercept constant, ~CI is the llne slope of the variable term, and log l/I terms are as defined in ~igure 6. Figure 6 illustrates that a plurality of wavelength pairs, all centered on the same wavelength (approximately 980 nm), can be used in the algorithms. These algorithms are standard in near-IR
analysis techniques and are easily programmed lnto suitablQ microprocessor circuitry by those skilled in the art. The use of these single variable term equations i8 highly desirablQ bQcausQ it allows simplifiQd instrumQnt calibration, thereby allowing the production of low cost instruments.
The intercept constant Ro and the slope constant nre initially determined for a "master unit" (which employs components similar or identical to those of the production units) by simple linear regression analyse~
of known samples, i.e., optical readings are obtained from the instrument beins~ constructed for a representative number of samples which have been previously accurately analyzed via another, well-established technique, and the optical readings and previously measured percentages are utilized to calculate sets of constant values for blood glucose 20~5599 content u~ing a conventional regression algorithm in a digital computer. The respective ~l 810pe and ~0 intercept values are then programmed into each production unit of the analyzing instrument 80 that S each production unit can directly compute values for blood glucose from optical data readings.
Another class of usable near-IR standard algorithms involves the use of multiple regression terms. Such terms can be individual log l/I terms or can be a multiple number of first or second derivative terms with or without a normalizing denomlnator. Such multiple terms may provide additional accuracy, but introduce much higher calibration expense which results - in a more expensive instrument.
Data on a plurality of physical parameters o~ the body can also be utilized in con~unction wlth multiple wavelength measurement of near-infrared interactance, as in prior U.S. Patent No. 4,633,087, to improve the accuracy of the present blood glucose measurements.
In use, the analysis instrument 10 i8 poBitioned 80 that its flat bottom surface rests on the skin directly above the prominent vein of the wrist of a tQst sub~ect. Light at the selected wavelengths emerging from the instrument interacts with venous blood of the sub~ect and iB detected by detector 28.
Detector 28 generates an electrical signal which is processed as described above.
A key to accurate analysis iB the ability of the user to locate the transmltter and detector filter (or window) directly over the prominent vein of the wrist.
The location device illustrated in Figure 3 greatly facilitates this procedure. The device 50 is constructed of, e.g., a plastic material and has an overall length L equal to the length L of the analysis _ 2045~99 instrument 10 of Figure 1. Two holes 51 are present in the device and are located in the same relation as 14 and 19 in Figure 1, on midline 52, a distance l apart corresponding to the distance l of Figure 1. The holes 51 permit observation of the prominent vein. When the device is placed on the wrist and the vein 18 centered in each hole 51, the wrist is marked (e.g. with a felt-tipped pen) at notches 53. The location device i8 then removed and replaced by the analysis instrument lO with assurance that the instrument is accurately disposed directly over the vein.
An alternate procedure for practicing the inventive method i8 accomplished by the use of fiber optic light probes as seen in Figure 4. These probes are connected with a known near-IR analysis instrument such as the TREBOR-70 scanning spectrophotometer. A
probe 60 is placed over the prominent vein and transmits near-IR energy of the desired wavelength(s).
The near-IR energy interacts with the blood constituents and is collected by a second probe 62 placed over the vein a short distance l from first probe 60. A detector associated with the analytical instrument provides an electrical signal which 1B
processed, as de~cribed above, to xeveal quantitative information concerning blood glucosQ.
WQ have found that accurate quantitative analysis of blood glucose levels can be mnde at a variety of wavelengths with both interactance and tran~mittance technologies. In the embodiment illustrated in Figures 2A and 2B near-IR light energy i8 transmitted through the finger of the test sub~ect and then detected by an optical detector. AB in all near-IR quantitative analysis instruments, a combination of measurement wavelengths is selected which emphasizes the glucose 20~5599 `~.
absorption and removes the affect of interfering absorption, for example, due to water, fat and protein.
Such selection i~ normally performed by computer search studies. Figure 7 illustrates such a search study.
Figure 7 presents correlation coefficient versus wavelength for an approximated first derivative algorithm and illustrates that the use of the wavelength pair of 980 ~ (plus and minus) 35 nm provides a high correlation between blood glucose and absorption of near-IR energy at those two wavelengths.
An example of one embodiment of the invention uses IREDs which provide near-IR energy at two frequencies which are, respectively, equidistant above and below approximately 980 nm, i.e., they can be represented by the formula 980 + x nm. The value of x is not critical 80 long as the two frequencies are centered on approximately 980 nm. For example x can be a number from 10 to 40.
Figure 8 shows that an optimum wavelength for a numerator in the first derivative division equation is approximately 1013 nm (i.e., 980 + 35 nm). Figure 9 shows that there are many wavelength regions that can provide midpoint wavelengths for use in the denominator of the first derivative division equation when the numerator utilizes g80 ~ 35 nm wavelengths. Examples of such regions are seen to be from 610 to 660 nm, from 910 to 980 nm and from 990 to 1080 nm.
204~99 Figure~ 10 and 11 illustrate optimum center wavelengths for use in second derivative division equations. Figure 10 6hows via a plot of correlation coefficient versus wavelength that the optimum numerator center frequency is approximately 1020 nm. Figure 11 ~hows that a denominator center frequency of about 850 nm is optimum.
As seen in Figure 2A, a near-IR probe 100 is adapted to be placed over the finger F of a test sub~ect and in this particular embodiment include~ a point source means of near-IR light energy comprised of two IRED~ 116 di~posed within of an upper flange 110. Each IRED is paired with a narrow bandpass optical filter 123 and i~
optically isolated via opaque light baffle 119. The inwardly-facing surface of flange 110 is provided with an optional optically clear window 114 for placement against the sub~ect~s finger.
Vpper flange 110 i~ hinged about shaft 111 to lower flange 120, and a spring 112 serves to maintain the flanges in a closed position. An optical detector 128 is disposed in lower flange 120 opposite the near-IR
source 116. The detector is disposed behind an optional window 129 which can be constructed of a material which is either optically clear or which excludes visible light yet permits near-IR light to pass. ~ finger stop 103 helps place and maintain the sub~ect's finger in it~
proper position within the probe 100. Each of the flanges is provided with light-shielding barriers 113 (shown in phantom in Figure 2A) to block ambient light from entering the probe.
In this embodiment the IREDs are pulsed, i.e.
energized in sequence, so that the detector 128 receive~
light transmitted from only one of the IRE~s at any one time. This pulsed IRED technolo~y is `- - 204~59g described in commonly owned U.S. Patent No. 4,286,327 which is incorporated by reference herein. In other similar embodiments a group of IREDs (and optional ~ narrow bandpa6s filterfi) with identical wavelength output can be pulsed.
- Probe 100 is in electrical connection with a proce~sor unit which is schematically illustrated in Figure 2A. The processor unit hou~es a power source, signal amplifying, data processing and display circuitry as described in connection with the embodiment of Figure 1 and standard in near-IR analy~is instrumentation.
An alternate embodiment is seen in Figure 2B. Here, probe 110 includes a single constant output IRED 116 installed behind an optional window 114. Light transmitted through the finger is gathered by optical funnel 112, which i~ constructed of a transparent material, and detected by multiple detectors 128. The detectors are optically isolated from one another by opaque light baffle 119. Each detector is paired with a narrow bandpass optical filter 123 and thu~ is set up to detect only light within the narrow wavelength range of its filter.
Near-IR point source means 116 can consist of one or more IREDs of known bandwidth and center frequency output or, as described above, can include a narrow bandpass optical filter within the light path to provide for the detection of only those wavelengths which are of interest. Multiple wavelengths can be utilized in transmission analysis and can be generated via multiple IREDs provided they are consecutively illuminated.
Another approach is to use a single IRED with multiple bandpass filters which are mechanically moved through the light path as seen in Figure 5B. A
20~S9~
third approach uses a single or group of IREDs capable of emittlng a plurality of desired wavelengths with the use of multiple optical filtQrs, each filter being married to a re~pective detector. Single IRED~ which emit two, three or four narrow bandwidths are commercially available.
In use, the finger of the test sub~ect i8 inserted between the flanges 110 of the probe 100. Near-IR
light energy i~ emitted by the point Bource meanB ~ i8 transmltted through the finger and is detected by optical detector 128. The electrical 6ignals produced by the detectors are transmitted via line 130 to a processor unit where the signal is amplified and data - processed (using the above algorithm) ns described in connection with the apparatus of Figure 1. Blood glucose level i~ displayed on a readout device which preferably includes a digital display.
The accuracy of this preferred near-IR
transmission embodiment can be further improved by altering the algorithm to include finger thickness as a parameter. According to Lambert's law, energy absorption is approximately proportional to the square of the thickness of the ob~ect. The thickness of the test sub~ect's finger can be quantified by installing a potentiometer 140 between the flanges of the probe 100 as sQen in Figures 2A and 2B. The output of the potentiometer, which is in electrical connection with the data processing circuitry, is indicative of finger thickness. A non-linear potentiometer can approximate the T2 value via its output alone 80 thst a separAte squaring calculation step is not required.
Although the invention has been described in connection with certain preferred embodiments, it is not limited to them. Modifications within the scope of - - 2a45s9~
the following claims will be apparent to those skilled in the art. For example, accurate measurements can be obtained from parts of the body besides the wrist and the finger. The algorithm used to calculate blood constituent concentration( 6 ) can be altered in accordance with known near-infrared analytical techniques.
Field of the Invention This invention relates to instruments and methods for the non-invasive quantitative measurement of blood glucose. More particularly, the invention relates to ~uch quantitative measurement via near-infrared interactance and transmittance.
Backqround of the Invention Information concerning the chemical composition of blood is widely used to assess the health characteri6tics of both people and animals. Blood analysi~ provides an indication of the current 6tatus of metabolism (e.g. glucose content) as well as level of ri~k a6sociated with certain ma~or illnesses (e.g.
risk of cardio-vascular disease as a function of cholesterol level). Blood analysis, by the detection of above or below normal levels of various substance~
also provides direct indication of the presence of many types of diseases and dysfunctions.
The normal method of determining blood chemi~try is by removing a sample of blood (e.g. 5-10 ml) and performing one or more standard chemical tests. These types of test~ are moderately expenslve, require one class of trained technicians to remove the blood and 2S another cla~s of trained technicians to perform the chemical tests. Moreover, the results of the blood - 204~99 "_ tests often are not available for several hours, and sometimes even several days.
Recently, an alternative type of technology (i.e.
~elf-contained in~truments) has been introduced for S relatively rapid blood ~creening of a large number of sub~ects. The~e instrument~, in general, use a much smaller blood sample (approximately .25 ml) from a "finger poke." This small blood sample is placed on a chemically-treated carrier and entered into the instrument. These instruments normally provide either an individual analyses (e.g. glucose level) or multiple analysis in a few moment~. These type~ of instrument~
unfortunately are quite co~tly, e.g., in the range of several thousand dollars.
A third clas~ of blood instrumentation i8 available for the specific purpose of determining glucose level in people with diabetes. This technology also uses a small sample from a finger poke and the sample is placed on a chemically treated carrier which is inserted into a portable battery operated instrument. In general, these instruments provide a single function; i.e. measurement of glucose. Although these specialized in~truments are relatively low cost ($300 or less iB typical), the cost of the di~posable carrier ~stick" must be considered. Since somQ
diabetic patients may require glucose analysis four or more time8 a day, the cost over a period of a year can become significant.
Current glucose analytical systems require blood to be extracted from the body prior to performing the analysis. Thi~ blood withdrawal requirement limits the application of such te~ting; many people who may be interested in knowing their glucose level are reluctant to have either their finger poked or blood samples - - 20g5~99 removed by hypodermic needle. This reluctance or anxiety in allowing blood sample removal i8 due to concern over the possibility of infection, discomfort (pain) and generalized patient fear.
Thus, there ifi a great need for non-invasive analytical instruments and methods that would provide essQntially the same accuracy as conventional blood glucose te~ts. Moreover, there is a need for a non-inva~ive low-cost method for measurement of glucose in diabetic patients.
Near-infrared ~sometimes referred to herein as simply "near-IR~) quantitative analysi~ is widely used in the field of agriculture for determining chemical compositions within grain, oilseeds, and other agricultural products. As an example, near-IR energy reflected from the surface of finely ground seeds and grain provides information concerning protein and moisturQ content. For a general introduction to near infrared quantitative analysis, see ~An Introduction to Near-Infrared Quantitative AnalysisU presented by Robert D. Rosenthal at the 1977 Annual Meeting of American Association of Cereal Chemlsts. Near-infrared technology has been extended to allow totally non-destructive measurements by using light transmission 2S through a sample as discussed in "Characteristics of Non-Destructive Near-Infrared Instruments for Grain and Food Products n by Robert D. Rosenthal, presented at the 1986 Meeting at the Japan Food Science InstitutQ.
Although this transmission approach avoids the need to finely grind the sample, it is not suited for use where access to two opposite surfaces is not available.
One example of this transmission approach is provided in V. S. Patent No. 4,621,643 (New, Jr. et al., 1986) relates to an optlcal oximeter apparatus for `~ - 20~599 determining pulse rate and degree of arterial oxygen saturation. Light energy iB passed through an appendage of the body, e.g. a finger, and strikes a detector positioned on a side of the appendàge opposite from the light source. Pulse rate and ~aturated oxygen are calculated from coefficients of extinction of light at the selected wavelengths.
Another approach to near-infrared quantitative analysis, using near-infrared interactance, was developed for non-invasively measuring body fat content. This approach i8 described in ~A New Approach for the Estimation of Body Composition2 Infrared Interactance", Joan M. Conway et al., The American Journal of Clinical Nutrition, 40~ Dec. 1984, pages 1123-1230. In thi~ non-invasive technique, a small optical probe that allows optical energy to enter the arm is placed on the biceps. The percent body fat of the entire body is dete~mined by measuring the spectrum change of the energy returned from an area ad~acent the light entry point.
SummarY of the Invention In accordance wlth the prQsent invention, a near-infrared quantitatiVQ analysis instrumQnt for measuring blood glucose compri~es means for introducing near-IR
energy into blood present in a body part of a sub~ect, means for detecting near-IR energy emerging from the sub~ect, means for converting an electrical signal corresponding to the detected energy into a readout indicative of the quantity of glucose present in the blood of the sub~ect, and mean~ for positioning the introducing means and detecting means ad~acent to the body part of the sub~ect.
20~ssss The pre~ent invention al~o provides methods for the near-infrared quantitative analysis of blood glucose, these methods including the steps of introducing near-IR energy into the blood within a body part of a sub~ect, detecting near-IR energy emerging from the sub~ect, the detector providing an electrical signal upon detecting said emerged energy, and processing the electricAl signal to provide a second signal indicative of the amount of glucose present in the blood. Some of thQse inventivQ methods utilize the principal of near-IR transmission while others utilize the principal of near-IR interaCtancQ.
In accordance with one aspect of the present invention, a near-infrared quantitative analysis in~trument for mea~uring blood gluco~e comprises means for introducing near-IR energy into blood present in a blood vessel, means for detecting near-IR energy following interactance of the same with thn blood, and means for position~ng the introducing means and detecting means over a blood vessel of the sub~ect.
This àspect of the invention further relates to methods wherein near-IR ener~y is introduced into a vein or artery of a sub~ect and interacts with blood glucose, the near-IR energy emerging from the sub~ect 25 i8 detected by a detector which provides an electrical signal, and the signal i~ processed to provide a readout indicative of the amount of glucose in the blood.
This aspect of the invention also relates to means and methodfi for marking a po~ition over a vein or artery of a sub~ect and then aligning a near-IR
analysis instrument with the markings to accurately position the instrument.
20~5~9 ~nother a~pect of the invention relates to an apparatus for measuring blood gluco~e via near-IR
transmission through a blood-containing body part, the apparatus including means for introducing near-IR
energy into one side of a body part, means for detecting near-IR energy emerging from an opposite side of the body part and means for positioning the near-IR
introducing and detecting means on opposite sides of the body part.
This a~pect of the invention also relates to methods for measuring blood glucose via near-IR
transmission including the steps of introducing near-IR
energy into one side of a blood-containing body part, detecting near-IR energy emerging from an opposite side of the body part and calculating blood glucose content.
~rief De3criPtion of the Drawinq~
FIG. 1 is a partially schematic elevational view of a near-infrared quantitative blood analysis instrument to which the present invention pertains.
FIGS. 2A and 2B are partially schematic elevational views of alternate embodiments of near-infrared quantitative analysis instruments.
FIG. 3 is an elevational view of a location device for use with the in6trument shown in FIG. 1.
2S FIG. 4 illustrates one embodiment for practicing the inventive method.
FIGS. SA and 5B illustrate two known configurations for interposing filters in a light path.
FIG. 6 i8 a plot of log (l/I) versus wavelength.
FIG. 7 illustrates a wavelength search study via a plot of correlation coefficient versus wavelength.
FIGS. 8 and 9 show plots of midpoint wavelength versu~ correlation coefficient for first derivative equations.
204~sg9 FIGS. 10 and 11 illustrate plots of correlation coefficient versu~ wavelength for second derivative equations.
Detailed DescriPtion of the Preferred Embodiments This invention uses the principle of light interactance to measure blood glucose level non-invasively by locating an optical transmitter snd a detector on the skin surface near either an artery or vein. Alternatively, the invention uses the principal of light transmi6sion through a portion of the body that has relatively uniform profusion of blood in order to measure non-inva~ively blood glucose.
In general, the arteries and veins of the human body are buried deep in the body to protect them from possible harm. However, in certain location~ of the body, the~e blood carrying vessels are close to the skin surface. This is particularly true for veins.
Some examples of such locations are at the crea~e of the elbow, the wrist, the back of the hand, and the bridge of the nose. Since the concentration of glucose is relatively constant in both the veins and arterie~, valid measurements can be obtained in either. However, because veins are generally closer to the skin's ~urface, they u~ually are the better candidate for non-invasive measurements.
The finger tip is another site particularly well suited for performing blood measurement~ with near-IR
light. The blood supply is distributed within the finger tip and, thus, ~mall variation~ in the placement _ 2~4S599 of a near-IR emitter or detector will not have a profound effect on the measurement re~ults.
According to one embodiment of the invention utilizing near-IR interactance analysis techniques, S near-IR light energy at bandwidths centering on one or more wavelengths of interest is passed through the skin and connective tissues and into a blood vessel of a sub~ect. A portion of the energy re-emerges from the blood vessel of the test sub~ect and is detected by a detQctor. Following amplification of the detector-genQratQd signal, the amplified output is processed into an output signal indicatinq the amount of glucose in the sub~ect's blood. The output signal drivQs a display device for providing a visual display of blood glucose content.
According to another embodiment of the invention utilizing near-IR transmission analysis techniques, near-IR light energy at bandwidths cent~ring on one or more wavelengths of interest is transmitted through a blood-containing portion of the body of a test sub~ect.
The near-IR energy emerges from the test sub~ect, opposite from the near-IR source, and is detected by a detector. Following amplification of the detector-generated signal, the amplified output is processed into an output fiignal indicating the amount of glucose in the sub~ect's blood.
In one embodiment utilizing near-IR interactance, the entire analytical instrument, including near-infrared source, transmitter, detector, amplifier, data processing circuitry and readout is contained within a lightweight hand-held unit. Infrared emitting diodes (IREDs) disposed in one chamber of the unit are focu~ed to transmit near-IR energy of preselected wavelength(s) to, e.g., a prominent vein of the wrist. The near-IR
23~599 energy interacts with the confitituents of the venous blood and is re-emitted from the vein. A detector housed within a second chamber of the unit is disposed along the vein a distance (1) from the emitter and S collects this energy. The detected signal is amplified and data proce~sed into a signal indicative of the amount of glucose in the blood. This signal is then fed to a readout device (preferably a digital readout) for recordation by a technician or direct analysis by a physician or the sub~ect himself.
Other near-IR apparatus, ~uch as the optical probe and associated instrumentation described in U.S. Patent No. 4,633,087 (Rosenthal), are useful in the practice of the present methods in which near-IR interactance is used to quantitatively measure blood glucose levels.
The present invention also includes a location device specially adapted to permit the user to locate the interactance instrument discussed above accurately along a vein. The location device permits the skin to be marked to ensure that repeated mQasurements are taken from the ~ame location, if desired.
A particularly preferred lightweight, hand-held interactance analysis instrument in accordance with the invention iB illustrated in Fig. 1. The instrument 10 includes one or more means for providing at least one point source of near-infrared energy of a predetermined half-power bandwidth centered on a wavelength of interest positioned within a first chamber 30 of the instrument 10. The near-infrared point source means are positioned 80 that near-infrared energy being emitted from the point source means will be focus~ed by lens 12 through window 14 and onto the ~kin of the test sub~ect. The near-infrared point source means may comprise one or a plurality of infrared emitting diodes 20~S~99 (IRED8). Two such IREDs 16 are visible in the embodiment illustrated in Fig. 1. In other embodiment employing a plurality of IREDs, three, four or more IRED~ may be utilized as the point source means.
In lieu of laborious characterization and sorting of each IRED, we prefer to provide narrow bandpass optical filters (as shown schematically in Fig. 1) between the infrared emitting diodes and the lens 12. A filter 23 is positioned between each IRED and lens 12 for filtering near infrared radiation exiting each IRED and thereby allowing a narrow band of near-infrared radiation of predetermined wavelength to pass through the filter and lens 12. Utilization of narrow bandpass optical filters provides for specific wavelength selection independent of the center wavelengths of the particular infrared emitting diodes being used.
Measurements can be taken inside the hslf power bandwidth of the IREDs, or alternatively, outside the half power bandwidth of the IRED~ a~ disclosed in commonly owned U.S. Patent No. 4,286,327. Figs. 5A and 5B illustrate two known configurations for interposing filters in a light path.
An optical detector, illustrated schematically and designated by reference numeral 28, is disposed within a lower end portion 42 of ~ ~econd chnmber 40 in case 20. Inner wall 22 is positioned between detector 28 and lens 12, thereby providing an optically-i~olating ma~k which prevents near infrared radiation from the point source mean~ and/or lens 12 from impinging directly on detector 28. Optical detector 28 generates an electrical signal when near-infrared radiation is detected.
The optical detector 28 i8 connected to the input of an electrical ~ignal amplifier 32 by suitable 1 1 2 a ~ ~ ~
electrical conducting means 33. Amplifier 32 may be an inexpensive integrated circuit (IC) signal amplifier, and amplifies the signals generated when near-IR energy strikes detector 28. The output of amplifier 32 is fed S to a data processor and display driver 34 which provides a signal to readout device 36. The readout dQvice 36 may have a digital display for directly displaying the amount of glucose present in the sub~Qct's blood.
The embodiment of Fig. 1 includes an optical filter 29 for shielding all but the desired near-IR
energy from detector 28. ~ilter 29 and window 14 are posit~oned for direct contact with the skin of the test sub~ect. An optically clear window can be employed in lieu of filter 29, if desired.
As noted earlier, this embodiment of the present invention utilizes the principal of near-IR
interactance for quantitative analysis. In interactance, light from a source is shielded by an opaque member from a detector 80 that only light that has interacted with the sub~ect is detected. Accurate measurements of the concentration of blood glucose can be made using many of the conventional algorithm~ used in near-IR quantitative analysis including those that have only a single variable term such as the following 2 APProximated First Derivative Alqorithm C = ~0 + Rl [log l/Ia - log l/I~]
APproximated Se~ond Derivati ve Alqorithm C = Ko + Rl [log l/I~ - 2~10g l/I~ + log l/Ic]
Normalized First Derivative Alqorithm llog l/Ia - log l~
C ' ~o + Kl [log l/II - log l/I~]
Normalized Second Oerivative Alqorit}un [log l/IA - 2~10g l/I~ + log ~ ]
C = Ro +
[log l/ID - 2~10g l/I~5 ~ log l/I~l where C denotes concentration of glucose present in the blood, Ro is the intercept constant, ~CI is the llne slope of the variable term, and log l/I terms are as defined in ~igure 6. Figure 6 illustrates that a plurality of wavelength pairs, all centered on the same wavelength (approximately 980 nm), can be used in the algorithms. These algorithms are standard in near-IR
analysis techniques and are easily programmed lnto suitablQ microprocessor circuitry by those skilled in the art. The use of these single variable term equations i8 highly desirablQ bQcausQ it allows simplifiQd instrumQnt calibration, thereby allowing the production of low cost instruments.
The intercept constant Ro and the slope constant nre initially determined for a "master unit" (which employs components similar or identical to those of the production units) by simple linear regression analyse~
of known samples, i.e., optical readings are obtained from the instrument beins~ constructed for a representative number of samples which have been previously accurately analyzed via another, well-established technique, and the optical readings and previously measured percentages are utilized to calculate sets of constant values for blood glucose 20~5599 content u~ing a conventional regression algorithm in a digital computer. The respective ~l 810pe and ~0 intercept values are then programmed into each production unit of the analyzing instrument 80 that S each production unit can directly compute values for blood glucose from optical data readings.
Another class of usable near-IR standard algorithms involves the use of multiple regression terms. Such terms can be individual log l/I terms or can be a multiple number of first or second derivative terms with or without a normalizing denomlnator. Such multiple terms may provide additional accuracy, but introduce much higher calibration expense which results - in a more expensive instrument.
Data on a plurality of physical parameters o~ the body can also be utilized in con~unction wlth multiple wavelength measurement of near-infrared interactance, as in prior U.S. Patent No. 4,633,087, to improve the accuracy of the present blood glucose measurements.
In use, the analysis instrument 10 i8 poBitioned 80 that its flat bottom surface rests on the skin directly above the prominent vein of the wrist of a tQst sub~ect. Light at the selected wavelengths emerging from the instrument interacts with venous blood of the sub~ect and iB detected by detector 28.
Detector 28 generates an electrical signal which is processed as described above.
A key to accurate analysis iB the ability of the user to locate the transmltter and detector filter (or window) directly over the prominent vein of the wrist.
The location device illustrated in Figure 3 greatly facilitates this procedure. The device 50 is constructed of, e.g., a plastic material and has an overall length L equal to the length L of the analysis _ 2045~99 instrument 10 of Figure 1. Two holes 51 are present in the device and are located in the same relation as 14 and 19 in Figure 1, on midline 52, a distance l apart corresponding to the distance l of Figure 1. The holes 51 permit observation of the prominent vein. When the device is placed on the wrist and the vein 18 centered in each hole 51, the wrist is marked (e.g. with a felt-tipped pen) at notches 53. The location device i8 then removed and replaced by the analysis instrument lO with assurance that the instrument is accurately disposed directly over the vein.
An alternate procedure for practicing the inventive method i8 accomplished by the use of fiber optic light probes as seen in Figure 4. These probes are connected with a known near-IR analysis instrument such as the TREBOR-70 scanning spectrophotometer. A
probe 60 is placed over the prominent vein and transmits near-IR energy of the desired wavelength(s).
The near-IR energy interacts with the blood constituents and is collected by a second probe 62 placed over the vein a short distance l from first probe 60. A detector associated with the analytical instrument provides an electrical signal which 1B
processed, as de~cribed above, to xeveal quantitative information concerning blood glucosQ.
WQ have found that accurate quantitative analysis of blood glucose levels can be mnde at a variety of wavelengths with both interactance and tran~mittance technologies. In the embodiment illustrated in Figures 2A and 2B near-IR light energy i8 transmitted through the finger of the test sub~ect and then detected by an optical detector. AB in all near-IR quantitative analysis instruments, a combination of measurement wavelengths is selected which emphasizes the glucose 20~5599 `~.
absorption and removes the affect of interfering absorption, for example, due to water, fat and protein.
Such selection i~ normally performed by computer search studies. Figure 7 illustrates such a search study.
Figure 7 presents correlation coefficient versus wavelength for an approximated first derivative algorithm and illustrates that the use of the wavelength pair of 980 ~ (plus and minus) 35 nm provides a high correlation between blood glucose and absorption of near-IR energy at those two wavelengths.
An example of one embodiment of the invention uses IREDs which provide near-IR energy at two frequencies which are, respectively, equidistant above and below approximately 980 nm, i.e., they can be represented by the formula 980 + x nm. The value of x is not critical 80 long as the two frequencies are centered on approximately 980 nm. For example x can be a number from 10 to 40.
Figure 8 shows that an optimum wavelength for a numerator in the first derivative division equation is approximately 1013 nm (i.e., 980 + 35 nm). Figure 9 shows that there are many wavelength regions that can provide midpoint wavelengths for use in the denominator of the first derivative division equation when the numerator utilizes g80 ~ 35 nm wavelengths. Examples of such regions are seen to be from 610 to 660 nm, from 910 to 980 nm and from 990 to 1080 nm.
204~99 Figure~ 10 and 11 illustrate optimum center wavelengths for use in second derivative division equations. Figure 10 6hows via a plot of correlation coefficient versus wavelength that the optimum numerator center frequency is approximately 1020 nm. Figure 11 ~hows that a denominator center frequency of about 850 nm is optimum.
As seen in Figure 2A, a near-IR probe 100 is adapted to be placed over the finger F of a test sub~ect and in this particular embodiment include~ a point source means of near-IR light energy comprised of two IRED~ 116 di~posed within of an upper flange 110. Each IRED is paired with a narrow bandpass optical filter 123 and i~
optically isolated via opaque light baffle 119. The inwardly-facing surface of flange 110 is provided with an optional optically clear window 114 for placement against the sub~ect~s finger.
Vpper flange 110 i~ hinged about shaft 111 to lower flange 120, and a spring 112 serves to maintain the flanges in a closed position. An optical detector 128 is disposed in lower flange 120 opposite the near-IR
source 116. The detector is disposed behind an optional window 129 which can be constructed of a material which is either optically clear or which excludes visible light yet permits near-IR light to pass. ~ finger stop 103 helps place and maintain the sub~ect's finger in it~
proper position within the probe 100. Each of the flanges is provided with light-shielding barriers 113 (shown in phantom in Figure 2A) to block ambient light from entering the probe.
In this embodiment the IREDs are pulsed, i.e.
energized in sequence, so that the detector 128 receive~
light transmitted from only one of the IRE~s at any one time. This pulsed IRED technolo~y is `- - 204~59g described in commonly owned U.S. Patent No. 4,286,327 which is incorporated by reference herein. In other similar embodiments a group of IREDs (and optional ~ narrow bandpa6s filterfi) with identical wavelength output can be pulsed.
- Probe 100 is in electrical connection with a proce~sor unit which is schematically illustrated in Figure 2A. The processor unit hou~es a power source, signal amplifying, data processing and display circuitry as described in connection with the embodiment of Figure 1 and standard in near-IR analy~is instrumentation.
An alternate embodiment is seen in Figure 2B. Here, probe 110 includes a single constant output IRED 116 installed behind an optional window 114. Light transmitted through the finger is gathered by optical funnel 112, which i~ constructed of a transparent material, and detected by multiple detectors 128. The detectors are optically isolated from one another by opaque light baffle 119. Each detector is paired with a narrow bandpass optical filter 123 and thu~ is set up to detect only light within the narrow wavelength range of its filter.
Near-IR point source means 116 can consist of one or more IREDs of known bandwidth and center frequency output or, as described above, can include a narrow bandpass optical filter within the light path to provide for the detection of only those wavelengths which are of interest. Multiple wavelengths can be utilized in transmission analysis and can be generated via multiple IREDs provided they are consecutively illuminated.
Another approach is to use a single IRED with multiple bandpass filters which are mechanically moved through the light path as seen in Figure 5B. A
20~S9~
third approach uses a single or group of IREDs capable of emittlng a plurality of desired wavelengths with the use of multiple optical filtQrs, each filter being married to a re~pective detector. Single IRED~ which emit two, three or four narrow bandwidths are commercially available.
In use, the finger of the test sub~ect i8 inserted between the flanges 110 of the probe 100. Near-IR
light energy i~ emitted by the point Bource meanB ~ i8 transmltted through the finger and is detected by optical detector 128. The electrical 6ignals produced by the detectors are transmitted via line 130 to a processor unit where the signal is amplified and data - processed (using the above algorithm) ns described in connection with the apparatus of Figure 1. Blood glucose level i~ displayed on a readout device which preferably includes a digital display.
The accuracy of this preferred near-IR
transmission embodiment can be further improved by altering the algorithm to include finger thickness as a parameter. According to Lambert's law, energy absorption is approximately proportional to the square of the thickness of the ob~ect. The thickness of the test sub~ect's finger can be quantified by installing a potentiometer 140 between the flanges of the probe 100 as sQen in Figures 2A and 2B. The output of the potentiometer, which is in electrical connection with the data processing circuitry, is indicative of finger thickness. A non-linear potentiometer can approximate the T2 value via its output alone 80 thst a separAte squaring calculation step is not required.
Although the invention has been described in connection with certain preferred embodiments, it is not limited to them. Modifications within the scope of - - 2a45s9~
the following claims will be apparent to those skilled in the art. For example, accurate measurements can be obtained from parts of the body besides the wrist and the finger. The algorithm used to calculate blood constituent concentration( 6 ) can be altered in accordance with known near-infrared analytical techniques.
Claims (32)
1. A near-infrared quantitative analysis instrument for non-invasive measurement of blood glucose in blood present in a body part of a subject, comprising:
(a) means for introducing near-infrared energy into blood present in a body part of a subject;
(b) a near-infrared detector for detecting near-infrared energy within the range of about 600 to 1110 nanometers emerging from the body part and for providing a signal upon detection of near-infrared energy within said range emerging from the body part;
(c) means for positioning both the near-infrared introducing means and the near-infrared detector closely adjacent to the body part so that near-infrared energy detected by the detector corresponds to blood glucose level in said body part; and (d) means for processing the signal produced by the detector into a second signal indicative of the quantity of glucose present in the blood of the subject.
(a) means for introducing near-infrared energy into blood present in a body part of a subject;
(b) a near-infrared detector for detecting near-infrared energy within the range of about 600 to 1110 nanometers emerging from the body part and for providing a signal upon detection of near-infrared energy within said range emerging from the body part;
(c) means for positioning both the near-infrared introducing means and the near-infrared detector closely adjacent to the body part so that near-infrared energy detected by the detector corresponds to blood glucose level in said body part; and (d) means for processing the signal produced by the detector into a second signal indicative of the quantity of glucose present in the blood of the subject.
2. An analysis instrument of claim 1 further including means for preventing near-infrared energy from the introducing means from impinging directly on the detector.
3. An analysis instrument of claim 2 wherein said introducing means includes a near-infrared energy source and transmitting means for transmitting said energy into the body part.
4. An analysis instrument of claim 3 wherein said source comprises at least one infrared emitting diode.
5. An analysis instrument of claim 3 wherein said transmitting means comprises a lens for focusing said energy onto the body part.
6. An analysis instrument of claim 2 wherein said processing means comprises amplifier means for amplifying the signal provided by said detector, and data processing means for converting the signal from the detector into said second signal.
7. An analysis instrument of claim 1 wherein said introducing means includes a near infrared source and a filter for selectively transmitting near-infrared energy which filter is disposed between said source and said body part.
8. An analysis instrument of claim 7 for blood glucose measurement wherein said filter selectively transmits near-infrared energy of between about 600 and about 1100 nanometers.
9. An analysis instrument of claim 1 wherein said introducing means provides a bandwidth centered on about 980 nanometers.
10. An analysis instrument of claim 1 wherein said positioning means comprises means for marking a position for said instrument over a blood vessel of a subject.
11. An analysis instrument of claim 1 wherein said positioning means comprises means for positioning said introducing means closely adjacent to one side of the body part and for positioning said detector closely adjacent to an opposite side of the body part whereby near-IR energy emitted by said introducing means is transmitted through said body part and detected by said detector.
12. An analysis instrument of claim 11 wherein the positioning means positions the introducing means and the detector on opposite sides of a finger.
13. An analysis instrument of claim 12 further including means for measuring the thickness of the body part and for providing a signal indicative of the thickness of the body part.
14. An analysis instrument of claim 13 wherein said means for providing an electrical signal comprises a variable resistor.
15. An analysis instrument of claim 11 wherein said introducing means comprises an infrared emitting diode.
16. An analysis instrument of claim 15 wherein said infrared emitting diode produces a bandwidth centered on about 980 nanometers.
17. An analysis instrument of claim 11 wherein said introducing means includes a near infrared source and a filter for selectively transmitting near-infrared energy which filter is disposed between said source and said body part.
18. An analysis instrument of claim 17 for blood glucose measurement wherein said filter selectively transmits near-infrared energy of between about 600 and about 1100 nanometers.
19. The analysis instrument of claim 11 further including at least one filter for selectively transmitting near-infrared energy, which filter is disposed between the detector and said body part.
20. An analysis instrument of claim 19 for blood glucose measurement wherein said filter selectively transmits near-infrared energy of between about 600 and about 1100 nanometers.
21. A non-invasive method for quantitatively analyzing blood glucose in blood of a subject, comprising:
(a) introducing at least one pair of wavelengths of near infrared energy into blood within a body part of the subject, said pair being centered on a wavelength within the range of about 600 to 1100 nanometers;
b) detecting near-infrared energy emerging from the subject with a detector which provides a signal upon detecting said energy emerging from the subject, and (c) processing the signal to provide a second signal indicative of the amount of glucose present in the blood of the subject.
(a) introducing at least one pair of wavelengths of near infrared energy into blood within a body part of the subject, said pair being centered on a wavelength within the range of about 600 to 1100 nanometers;
b) detecting near-infrared energy emerging from the subject with a detector which provides a signal upon detecting said energy emerging from the subject, and (c) processing the signal to provide a second signal indicative of the amount of glucose present in the blood of the subject.
22. The method of claim 21 wherein near infrared energy centered on about 980 nanometers is introduced into the blood within said body part.
23. The analysis instrument of claim 1 wherein said introducing means provides at least one wavelength pair centered on about 980 nanometers.
24. The method of claim 21 wherein at least one pair of wavelengths of near infrared energy centered on about 980 nanometers is introduced into the blood within said body part.
25. The analysis instrument of claim 1 wherein the signal processing means processes the signal according to the formula C = K0 + K1 [log 1/Ic - log 1/IH]
wherein C is concentration of glucose present in the blood, K0 is an intercept constant, K1 is line slope of [log 1/Ic - log 1/IH]
and log 1/Ic and log 1/IH each represent an optical density value at corresponding wavelengths G and H.
wherein C is concentration of glucose present in the blood, K0 is an intercept constant, K1 is line slope of [log 1/Ic - log 1/IH]
and log 1/Ic and log 1/IH each represent an optical density value at corresponding wavelengths G and H.
26. The analysis instrument of claim 1 wherein the signal processing means processes the signal according to the formula C = K0 + K1 [log 1/IA - 2*log 1/IB + log 1/IC]
wherein C is concentration of glucose present in the blood, K0 is an intercept constant, K1 is line scope of [log 1/IA - 2*log 1/IB + log 1/IC]
and log 1/IA, log 1/IB, and log 1/IC each represent an optical density value at corresponding wavelengths A, B and C.
wherein C is concentration of glucose present in the blood, K0 is an intercept constant, K1 is line scope of [log 1/IA - 2*log 1/IB + log 1/IC]
and log 1/IA, log 1/IB, and log 1/IC each represent an optical density value at corresponding wavelengths A, B and C.
27. The analysis instrument of claim 1 wherein the signal process means processes the signal according to the formula C = K0 + K1 wherein C is concentration of glucose present in the blood, K0 is an intercept constant, K1 is line slope of and log 1/IC, log 1/IB, log 1/II and log 1/IJ each represent an optical density value at corresponding wavelengths G, H, I and J.
28 The analysis instrument of claim 1 wherein the signal processing means processes the signal according to the formula C = K0 + K1 wherein C is concentration of glucose present in the blood, K0 is an intercept constant, K1 is the line slope of and log 1/IA, log 1/IB, log 1/IC, log 1/ID, log 1/IE, and log 1/IP each represent an optical density value at corresponding wavelengths A, B, C, D, E and F.
29. The method of claim 21 wherein the signal is processed according to the formula C = K0 + K1 [log 1/IG - log 1/IR]
wherein C is concentration of glucose present in the blood, K0 is an intercept constant, K1 is line slope of [log 1/IG - log 1/IH]
and log 1/IG and log 1/IH each represent an optical density value at corresponding wavelengths G and H
wherein C is concentration of glucose present in the blood, K0 is an intercept constant, K1 is line slope of [log 1/IG - log 1/IH]
and log 1/IG and log 1/IH each represent an optical density value at corresponding wavelengths G and H
30. The method of claim 21 wherein the signal processing means processes the signal according to the formula C = K0 + K1 [log 1/IA - 2*log 1/IH + log 1/IC]
wherein C is concentration of glucose present in the blood, K0 is an intercept constant, K1 is line slope of [log 1/IA -2*log 1/IB + log 1/IC]
and log 1/IA, log 1/IB + log 1/IC]
and log 1/IA, log 1/I?B, and log 1/IC each represent an optical density value at corresponding wavelengths A, B and C.
wherein C is concentration of glucose present in the blood, K0 is an intercept constant, K1 is line slope of [log 1/IA -2*log 1/IB + log 1/IC]
and log 1/IA, log 1/IB + log 1/IC]
and log 1/IA, log 1/I?B, and log 1/IC each represent an optical density value at corresponding wavelengths A, B and C.
31. The method of claim 21 wherein the signal processing means processes the signal according to the formula C = K0 + K1 wherein C is concentration of glucose present in the blood, K0 is an intercept constant, K1 is line slope of and log 1/IC, log 1/IH, log 1/II and log 1/IJ each represent ar-optical density value at corresponding wavelengths G, H, I and J.
32. The method of claim 21 wherein the signal processing means processes the signal according to the formula C = K0 + K1 wherein C is concentration of glucose present in the blood, K0 is an intercept constant, K1 is the line slope of and log 1/IA, log 1/IB, log 1/IC, log 1/ID, log 1/IE, and log 1/IF each represent an optical density value at corresponding wavelengths A, B, C, D, E and F.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/298,904 US5028787A (en) | 1989-01-19 | 1989-01-19 | Non-invasive measurement of blood glucose |
| US298,904 | 1989-01-19 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2045599A1 CA2045599A1 (en) | 1990-07-20 |
| CA2045599C true CA2045599C (en) | 1996-10-01 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002045599A Expired - Fee Related CA2045599C (en) | 1989-01-19 | 1990-01-17 | Non-invasive measurement of blood glucose |
Country Status (10)
| Country | Link |
|---|---|
| US (1) | US5028787A (en) |
| EP (1) | EP0456716B1 (en) |
| JP (1) | JPH02191434A (en) |
| KR (1) | KR0145695B1 (en) |
| AT (1) | ATE163844T1 (en) |
| AU (1) | AU5042190A (en) |
| CA (1) | CA2045599C (en) |
| DE (1) | DE69032126T2 (en) |
| ES (1) | ES2114860T3 (en) |
| WO (1) | WO1990007905A1 (en) |
Families Citing this family (389)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5218207A (en) * | 1989-01-19 | 1993-06-08 | Futrex, Inc. | Using led harmonic wavelengths for near-infrared quantitative |
| US5204532A (en) * | 1989-01-19 | 1993-04-20 | Futrex, Inc. | Method for providing general calibration for near infrared instruments for measurement of blood glucose |
| US6066847A (en) * | 1989-01-19 | 2000-05-23 | Futrex Inc. | Procedure for verifying the accuracy of non-invasive blood glucose measurement instruments |
| GB2228314B (en) * | 1989-02-16 | 1992-11-18 | Hamamatsu Photonics Kk | Examination apparatus |
| US5178142A (en) * | 1989-05-23 | 1993-01-12 | Vivascan Corporation | Electromagnetic method and apparatus to measure constituents of human or animal tissue |
| DE68902738T2 (en) * | 1989-05-23 | 1993-01-28 | Biosensors Technology Inc | METHOD FOR DETERMINING BY MEANS OF RADIATION ABSORPTION OF SUBSTANCES IN ABSORBENT AND SCATTERING MATRIX MATERIALS. |
| US5137023A (en) * | 1990-04-19 | 1992-08-11 | Worcester Polytechnic Institute | Method and apparatus for monitoring blood analytes noninvasively by pulsatile photoplethysmography |
| US5183042A (en) * | 1989-05-23 | 1993-02-02 | Vivascan Corporation | Electromagnetic method and apparatus to measure constituents of human or animal tissue |
| US5112124A (en) * | 1990-04-19 | 1992-05-12 | Worcester Polytechnic Institute | Method and apparatus for measuring the concentration of absorbing substances |
| CA2028261C (en) * | 1989-10-28 | 1995-01-17 | Won Suck Yang | Non-invasive method and apparatus for measuring blood glucose concentration |
| US5342789A (en) * | 1989-12-14 | 1994-08-30 | Sensor Technologies, Inc. | Method and device for detecting and quantifying glucose in body fluids |
| US6040194A (en) * | 1989-12-14 | 2000-03-21 | Sensor Technologies, Inc. | Methods and device for detecting and quantifying substances in body fluids |
| US5070874A (en) * | 1990-01-30 | 1991-12-10 | Biocontrol Technology, Inc. | Non-invasive determination of glucose concentration in body of patients |
| US5222495A (en) * | 1990-02-02 | 1993-06-29 | Angiomedics Ii, Inc. | Non-invasive blood analysis by near infrared absorption measurements using two closely spaced wavelengths |
| AU7302991A (en) * | 1990-02-02 | 1991-08-21 | Boston Advanced Technologies, Inc. | Systems for material analysis based on reflectance ratio detection |
| US5246004A (en) * | 1990-02-02 | 1993-09-21 | Angiomedics Ii, Inc. | Infrared cholesterol sensor |
| US5239180A (en) * | 1990-02-02 | 1993-08-24 | Boston Advnaced Technologies, Inc. | Laser systems for food analysis based on reflectance ratio detection |
| US5222496A (en) * | 1990-02-02 | 1993-06-29 | Angiomedics Ii, Inc. | Infrared glucose sensor |
| NZ238717A (en) * | 1990-06-27 | 1994-08-26 | Futrex Inc | Blood glucose level measured by transmitting near-infrared energy through body part |
| US6246894B1 (en) | 1993-02-01 | 2001-06-12 | In-Line Diagnostics Corporation | System and method for measuring blood urea nitrogen, blood osmolarity, plasma free hemoglobin and tissue water content |
| US6266546B1 (en) | 1990-10-06 | 2001-07-24 | In-Line Diagnostics Corporation | System for noninvasive hematocrit monitoring |
| US6681128B2 (en) | 1990-10-06 | 2004-01-20 | Hema Metrics, Inc. | System for noninvasive hematocrit monitoring |
| US6725072B2 (en) | 1990-10-06 | 2004-04-20 | Hema Metrics, Inc. | Sensor for transcutaneous measurement of vascular access blood flow |
| US6580086B1 (en) * | 1999-08-26 | 2003-06-17 | Masimo Corporation | Shielded optical probe and method |
| GB9106672D0 (en) * | 1991-03-28 | 1991-05-15 | Abbey Biosystems Ltd | Method and apparatus for glucose concentration monitoring |
| US6987994B1 (en) | 1991-09-03 | 2006-01-17 | Datex-Ohmeda, Inc. | Pulse oximetry SpO2 determination |
| US5934277A (en) | 1991-09-03 | 1999-08-10 | Datex-Ohmeda, Inc. | System for pulse oximetry SpO2 determination |
| US6714803B1 (en) | 1991-09-03 | 2004-03-30 | Datex-Ohmeda, Inc. | Pulse oximetry SpO2 determination |
| US5282466A (en) * | 1991-10-03 | 1994-02-01 | Medtronic, Inc. | System for disabling oximeter in presence of ambient light |
| WO1993006774A1 (en) * | 1991-10-03 | 1993-04-15 | Medtronic, Inc. | Method and apparatus for determining hematocrit in blood |
| AU2800892A (en) * | 1991-10-03 | 1993-05-03 | Medtronic, Inc. | Method and apparatus for determining oxygen saturation |
| US5277181A (en) * | 1991-12-12 | 1994-01-11 | Vivascan Corporation | Noninvasive measurement of hematocrit and hemoglobin content by differential optical analysis |
| AU2245092A (en) * | 1991-12-31 | 1993-07-28 | Vivascan Corporation | Blood constituent determination based on differential spectral analysis |
| US5370114A (en) * | 1992-03-12 | 1994-12-06 | Wong; Jacob Y. | Non-invasive blood chemistry measurement by stimulated infrared relaxation emission |
| US5348002A (en) * | 1992-04-23 | 1994-09-20 | Sirraya, Inc. | Method and apparatus for material analysis |
| US5672875A (en) * | 1992-07-15 | 1997-09-30 | Optix Lp | Methods of minimizing scattering and improving tissue sampling in non-invasive testing and imaging |
| US6420709B1 (en) | 1992-07-15 | 2002-07-16 | Optix Lp | Methods of minimizing scattering and improving tissue sampling in non-invasive testing and imaging |
| US5321265A (en) * | 1992-07-15 | 1994-06-14 | Block Myron J | Non-invasive testing |
| US5818048A (en) * | 1992-07-15 | 1998-10-06 | Optix Lp | Rapid non-invasive optical analysis using broad bandpass spectral processing |
| US5434412A (en) * | 1992-07-15 | 1995-07-18 | Myron J. Block | Non-spectrophotometric measurement of analyte concentrations and optical properties of objects |
| US5424545A (en) * | 1992-07-15 | 1995-06-13 | Myron J. Block | Non-invasive non-spectrophotometric infrared measurement of blood analyte concentrations |
| US5348003A (en) * | 1992-09-03 | 1994-09-20 | Sirraya, Inc. | Method and apparatus for chemical analysis |
| US5433197A (en) * | 1992-09-04 | 1995-07-18 | Stark; Edward W. | Non-invasive glucose measurement method and apparatus |
| US6172743B1 (en) | 1992-10-07 | 2001-01-09 | Chemtrix, Inc. | Technique for measuring a blood analyte by non-invasive spectrometry in living tissue |
| IL107396A (en) * | 1992-11-09 | 1997-02-18 | Boehringer Mannheim Gmbh | Method and apparatus for analytical determination of glucose in a biological matrix |
| DE4314835A1 (en) * | 1993-05-05 | 1994-11-10 | Boehringer Mannheim Gmbh | Method and device for analysing glucose in a biological matrix |
| US5379764A (en) * | 1992-12-09 | 1995-01-10 | Diasense, Inc. | Non-invasive determination of analyte concentration in body of mammals |
| US5448992A (en) * | 1992-12-10 | 1995-09-12 | Sunshine Medical Instruments, Inc. | Method and apparatus for non-invasive phase sensitive measurement of blood glucose concentration |
| US5398681A (en) * | 1992-12-10 | 1995-03-21 | Sunshine Medical Instruments, Inc. | Pocket-type instrument for non-invasive measurement of blood glucose concentration |
| DE4242232C2 (en) * | 1992-12-15 | 1998-12-10 | Burkhard Kuhls | Device and method for the non-invasive determination of the concentration of polarizing substances in the human body |
| US5515847A (en) * | 1993-01-28 | 1996-05-14 | Optiscan, Inc. | Self-emission noninvasive infrared spectrophotometer |
| US5615672A (en) * | 1993-01-28 | 1997-04-01 | Optiscan, Inc. | Self-emission noninvasive infrared spectrophotometer with body temperature compensation |
| US5313941A (en) * | 1993-01-28 | 1994-05-24 | Braig James R | Noninvasive pulsed infrared spectrophotometer |
| WO1995006431A2 (en) | 1993-08-24 | 1995-03-09 | Robinson Mark R | A robust accurate non-invasive analyte monitor |
| DE4337570A1 (en) * | 1993-11-04 | 1995-05-11 | Boehringer Mannheim Gmbh | Method for the analysis of glucose in a biological matrix |
| DE4339067A1 (en) * | 1993-11-16 | 1995-05-18 | Jenoptik Jena Gmbh | Method and arrangement for the non-invasive, transcutaneous determination of substance concentrations in body fluid or human tissue |
| US5459317A (en) * | 1994-02-14 | 1995-10-17 | Ohio University | Method and apparatus for non-invasive detection of physiological chemicals, particularly glucose |
| DE9404312U1 (en) * | 1994-03-09 | 1994-06-23 | Mira Gmbh | Medical diagnostic tool |
| JPH07250826A (en) * | 1994-03-14 | 1995-10-03 | Sony Corp | Blood sugar value measuring apparatus |
| JP3364819B2 (en) * | 1994-04-28 | 2003-01-08 | 日本光電工業株式会社 | Blood absorption substance concentration measurement device |
| TW275570B (en) * | 1994-05-05 | 1996-05-11 | Boehringer Mannheim Gmbh | |
| US5774213A (en) * | 1995-04-21 | 1998-06-30 | Trebino; Rick P. | Techniques for measuring difference of an optical property at two wavelengths by modulating two sources to have opposite-phase components at a common frequency |
| HU216847B (en) * | 1995-05-23 | 1999-12-28 | Gyula Domján | Method and arrangement for prompt non-invasive determination of blood parameters |
| US5743262A (en) * | 1995-06-07 | 1998-04-28 | Masimo Corporation | Blood glucose monitoring system |
| AU6256196A (en) * | 1995-06-07 | 1996-12-30 | Blackbox, Inc. | Method for noninvasive intermittent and/or continuous hemogl obin, arterial oxygen content, and hematocrit determination |
| US5625449A (en) * | 1995-07-31 | 1997-04-29 | Lucent Technologies Inc. | Apparatus for simultaneously measuring the thickness of, and the optical intensity transmitted through, a sample body |
| US6240306B1 (en) | 1995-08-09 | 2001-05-29 | Rio Grande Medical Technologies, Inc. | Method and apparatus for non-invasive blood analyte measurement with fluid compartment equilibration |
| US6152876A (en) | 1997-04-18 | 2000-11-28 | Rio Grande Medical Technologies, Inc. | Method for non-invasive blood analyte measurement with improved optical interface |
| US5655530A (en) * | 1995-08-09 | 1997-08-12 | Rio Grande Medical Technologies, Inc. | Method for non-invasive blood analyte measurement with improved optical interface |
| US6212424B1 (en) | 1998-10-29 | 2001-04-03 | Rio Grande Medical Technologies, Inc. | Apparatus and method for determination of the adequacy of dialysis by non-invasive near-infrared spectroscopy |
| US6025597A (en) * | 1995-10-17 | 2000-02-15 | Optiscan Biomedical Corporation | Non-invasive infrared absorption spectrometer for measuring glucose or other constituents in a human or other body |
| US6072180A (en) * | 1995-10-17 | 2000-06-06 | Optiscan Biomedical Corporation | Non-invasive infrared absorption spectrometer for the generation and capture of thermal gradient spectra from living tissue |
| US6002954A (en) * | 1995-11-22 | 1999-12-14 | The Regents Of The University Of California | Detection of biological molecules using boronate-based chemical amplification and optical sensors |
| US6766183B2 (en) | 1995-11-22 | 2004-07-20 | Medtronic Minimed, Inc. | Long wave fluorophore sensor compounds and other fluorescent sensor compounds in polymers |
| WO1997019188A1 (en) | 1995-11-22 | 1997-05-29 | Minimed, Inc. | Detection of biological molecules using chemical amplification and optical sensors |
| US6041247A (en) * | 1995-11-29 | 2000-03-21 | Instrumentarium Corp | Non-invasive optical measuring sensor and measuring method |
| WO1997030629A1 (en) * | 1996-02-23 | 1997-08-28 | Diasense, Inc. | Method and apparatus for non-invasive blood glucose sensing |
| JP3599878B2 (en) * | 1996-03-01 | 2004-12-08 | テルモ株式会社 | Blood glucose meter |
| DE19609368A1 (en) * | 1996-03-04 | 1997-09-11 | Biotronik Mess & Therapieg | Device for controlling a cardiac stimulator based on blood oxygen saturation |
| US5666956A (en) * | 1996-05-20 | 1997-09-16 | Buchert; Janusz Michal | Instrument and method for non-invasive monitoring of human tissue analyte by measuring the body's infrared radiation |
| DE19629342C2 (en) * | 1996-07-20 | 1999-09-02 | Epsa Elektronik Und Praezision | Method and arrangement for the non-invasive, transcutaneous determination of substance concentrations in body tissues |
| DE19780856D2 (en) * | 1996-08-16 | 1999-09-23 | Roche Diagnostics Gmbh | Control system for monitoring the regular intake of a drug |
| US5871442A (en) * | 1996-09-10 | 1999-02-16 | International Diagnostics Technologies, Inc. | Photonic molecular probe |
| US6594510B2 (en) | 1996-09-10 | 2003-07-15 | Xoetronics Llc | Photonic molecular probe |
| US6018673A (en) | 1996-10-10 | 2000-01-25 | Nellcor Puritan Bennett Incorporated | Motion compatible sensor for non-invasive optical blood analysis |
| US5800349A (en) * | 1996-10-15 | 1998-09-01 | Nonin Medical, Inc. | Offset pulse oximeter sensor |
| US6117099A (en) | 1996-10-23 | 2000-09-12 | In-Line Diagnostics Corporation | System and method for noninvasive hemodynamic measurements in hemodialysis shunts |
| WO1998022820A1 (en) | 1996-11-21 | 1998-05-28 | Lawrence Livermore National Laboratory | Detection of biological molecules using boronate-based chemical amplification and optical sensors |
| US8932227B2 (en) | 2000-07-28 | 2015-01-13 | Lawrence A. Lynn | System and method for CO2 and oximetry integration |
| US9042952B2 (en) | 1997-01-27 | 2015-05-26 | Lawrence A. Lynn | System and method for automatic detection of a plurality of SPO2 time series pattern types |
| US9468378B2 (en) | 1997-01-27 | 2016-10-18 | Lawrence A. Lynn | Airway instability detection system and method |
| US5910109A (en) | 1997-02-20 | 1999-06-08 | Emerging Technology Systems, Llc | Non-invasive glucose measuring device and method for measuring blood glucose |
| US6309884B1 (en) * | 1997-02-26 | 2001-10-30 | Diasense, Inc. | Individual calibration of blood glucose for supporting noninvasive self-monitoring blood glucose |
| US5961451A (en) * | 1997-04-07 | 1999-10-05 | Motorola, Inc. | Noninvasive apparatus having a retaining member to retain a removable biosensor |
| US6560352B2 (en) | 1999-10-08 | 2003-05-06 | Lumidigm, Inc. | Apparatus and method of biometric identification or verification of individuals using optical spectroscopy |
| US7890158B2 (en) | 2001-06-05 | 2011-02-15 | Lumidigm, Inc. | Apparatus and method of biometric determination using specialized optical spectroscopy systems |
| US6628809B1 (en) | 1999-10-08 | 2003-09-30 | Lumidigm, Inc. | Apparatus and method for identification of individuals by near-infrared spectrum |
| US20070191697A1 (en) | 2006-02-10 | 2007-08-16 | Lynn Lawrence A | System and method for SPO2 instability detection and quantification |
| US9521971B2 (en) | 1997-07-14 | 2016-12-20 | Lawrence A. Lynn | System and method for automatic detection of a plurality of SPO2 time series pattern types |
| US6343223B1 (en) * | 1997-07-30 | 2002-01-29 | Mallinckrodt Inc. | Oximeter sensor with offset emitters and detector and heating device |
| US6115621A (en) * | 1997-07-30 | 2000-09-05 | Nellcor Puritan Bennett Incorporated | Oximetry sensor with offset emitters and detector |
| GB2328279B (en) | 1997-08-12 | 2001-10-10 | Abbott Lab | Optical glucose detector |
| GB2329015B (en) * | 1997-09-05 | 2002-02-13 | Samsung Electronics Co Ltd | Method and device for noninvasive measurement of concentrations of blood components |
| US6804543B2 (en) | 1998-02-05 | 2004-10-12 | Hema Metrics, Inc. | Sensor for transcutaneous measurement of vascular access blood flow |
| DE19807939C1 (en) * | 1998-02-25 | 1999-09-30 | Siemens Ag | Non-invasive blood glucose concentration determination in vivo |
| WO1999044493A1 (en) | 1998-03-06 | 1999-09-10 | Dittel Rudolf H | Determination system for the direct qualitative and quantitative, almost immediate, highly specific, non-invasive detection of substances contained in the blood through measurement of spectral signatures |
| US6002953A (en) * | 1998-05-06 | 1999-12-14 | Optix Lp | Non-invasive IR transmission measurement of analyte in the tympanic membrane |
| US6097975A (en) * | 1998-05-13 | 2000-08-01 | Biosensor, Inc. | Apparatus and method for noninvasive glucose measurement |
| US6844166B1 (en) | 1998-09-11 | 2005-01-18 | Sensor Technologies Inc. | Recombinant reduced valency carbohydrate binding ligands |
| AU6153699A (en) * | 1998-09-18 | 2000-04-10 | Walter K. Proniewicz | Noninvasive measurement of blood sugar based on optoelectronic observations of the eye |
| US6064898A (en) * | 1998-09-21 | 2000-05-16 | Essential Medical Devices | Non-invasive blood component analyzer |
| US6441388B1 (en) | 1998-10-13 | 2002-08-27 | Rio Grande Medical Technologies, Inc. | Methods and apparatus for spectroscopic calibration model transfer |
| US6424851B1 (en) | 1998-10-13 | 2002-07-23 | Medoptix, Inc. | Infrared ATR glucose measurement system (II) |
| US6157041A (en) * | 1998-10-13 | 2000-12-05 | Rio Grande Medical Technologies, Inc. | Methods and apparatus for tailoring spectroscopic calibration models |
| US7098037B2 (en) | 1998-10-13 | 2006-08-29 | Inlight Solutions, Inc. | Accommodating subject and instrument variations in spectroscopic determinations |
| WO2000029206A1 (en) * | 1998-11-13 | 2000-05-25 | Sensor Technologies Inc. | Monodisperse preparations useful with implanted devices |
| US6067463A (en) * | 1999-01-05 | 2000-05-23 | Abbott Laboratories | Method and apparatus for non-invasively measuring the amount of glucose in blood |
| KR100382817B1 (en) * | 1999-01-20 | 2003-05-09 | 엘지.필립스 엘시디 주식회사 | A pattern for detecting the living things and thin film transistor optical sensor with the same |
| US6151517A (en) * | 1999-01-22 | 2000-11-21 | Futrex Inc. | Method and apparatus for noninvasive quantitative measurement of blood analytes |
| US6959211B2 (en) | 1999-03-10 | 2005-10-25 | Optiscan Biomedical Corp. | Device for capturing thermal spectra from tissue |
| US6675031B1 (en) | 1999-04-14 | 2004-01-06 | Mallinckrodt Inc. | Method and circuit for indicating quality and accuracy of physiological measurements |
| US6475800B1 (en) | 1999-07-22 | 2002-11-05 | Instrumentation Metrics, Inc. | Intra-serum and intra-gel for modeling human skin tissue |
| DE60031427T2 (en) * | 1999-08-31 | 2007-09-20 | NIR Diagnostics Inc., Campbellville | METHOD FOR CALIBRATING A SPECTROSCOPY DEVICE |
| US6682938B1 (en) | 1999-09-15 | 2004-01-27 | The Regents Of The University Of California | Glucose sensing molecules having selected fluorescent properties |
| US6673625B2 (en) | 1999-09-15 | 2004-01-06 | The Regents Of The University Of California | Saccharide sensing molecules having enhanced fluorescent properties |
| US6816605B2 (en) | 1999-10-08 | 2004-11-09 | Lumidigm, Inc. | Methods and systems for biometric identification of individuals using linear optical spectroscopy |
| EP2322085B1 (en) | 2000-04-17 | 2014-03-12 | Covidien LP | Pulse oximeter sensor with piece-wise function |
| US8224412B2 (en) | 2000-04-17 | 2012-07-17 | Nellcor Puritan Bennett Llc | Pulse oximeter sensor with piece-wise function |
| US6477392B1 (en) | 2000-07-14 | 2002-11-05 | Futrex Inc. | Calibration of near infrared quantitative measurement device using optical measurement cross-products |
| US6549861B1 (en) | 2000-08-10 | 2003-04-15 | Euro-Celtique, S.A. | Automated system and method for spectroscopic analysis |
| US6675030B2 (en) | 2000-08-21 | 2004-01-06 | Euro-Celtique, S.A. | Near infrared blood glucose monitoring system |
| US6741876B1 (en) | 2000-08-31 | 2004-05-25 | Cme Telemetrix Inc. | Method for determination of analytes using NIR, adjacent visible spectrum and discrete NIR wavelenths |
| US8384885B2 (en) | 2000-09-20 | 2013-02-26 | Hitachi, Ltd. | Personal identification system |
| JP2002092616A (en) * | 2000-09-20 | 2002-03-29 | Hitachi Ltd | Individual authentication device |
| US6522903B1 (en) * | 2000-10-19 | 2003-02-18 | Medoptix, Inc. | Glucose measurement utilizing non-invasive assessment methods |
| US6746407B2 (en) * | 2000-12-29 | 2004-06-08 | Hema Metrics, Inc. | Method of measuring transcutaneous access blood flow |
| US20060195041A1 (en) | 2002-05-17 | 2006-08-31 | Lynn Lawrence A | Centralized hospital monitoring system for automatically detecting upper airway instability and for preventing and aborting adverse drug reactions |
| US20090281838A1 (en) | 2008-05-07 | 2009-11-12 | Lawrence A. Lynn | Medical failure pattern search engine |
| US9053222B2 (en) | 2002-05-17 | 2015-06-09 | Lawrence A. Lynn | Patient safety processor |
| US6927246B2 (en) * | 2001-02-15 | 2005-08-09 | Medtronic Minimed, Inc. | Polymers functionalized with fluorescent boronate motifs and methods for making them |
| US6862091B2 (en) | 2001-04-11 | 2005-03-01 | Inlight Solutions, Inc. | Illumination device and method for spectroscopic analysis |
| US6865408B1 (en) | 2001-04-11 | 2005-03-08 | Inlight Solutions, Inc. | System for non-invasive measurement of glucose in humans |
| US7043288B2 (en) | 2002-04-04 | 2006-05-09 | Inlight Solutions, Inc. | Apparatus and method for spectroscopic analysis of tissue to detect diabetes in an individual |
| US6574490B2 (en) | 2001-04-11 | 2003-06-03 | Rio Grande Medical Technologies, Inc. | System for non-invasive measurement of glucose in humans |
| US7126682B2 (en) * | 2001-04-11 | 2006-10-24 | Rio Grande Medical Technologies, Inc. | Encoded variable filter spectrometer |
| US6983176B2 (en) | 2001-04-11 | 2006-01-03 | Rio Grande Medical Technologies, Inc. | Optically similar reference samples and related methods for multivariate calibration models used in optical spectroscopy |
| US7167734B2 (en) * | 2001-04-13 | 2007-01-23 | Abbott Laboratories | Method for optical measurements of tissue to determine disease state or concentration of an analyte |
| US6559655B1 (en) | 2001-04-30 | 2003-05-06 | Zeltex, Inc. | System and method for analyzing agricultural products on harvesting equipment |
| US6704588B2 (en) | 2001-06-16 | 2004-03-09 | Rafat R. Ansari | Method and apparatus for the non-invasive measurement of blood glucose levels in humans |
| US20030040683A1 (en) * | 2001-07-06 | 2003-02-27 | Peter Rule | Site selection for determining analyte concentration in living tissue |
| US6754516B2 (en) | 2001-07-19 | 2004-06-22 | Nellcor Puritan Bennett Incorporated | Nuisance alarm reductions in a physiological monitor |
| US6631282B2 (en) * | 2001-08-09 | 2003-10-07 | Optiscan Biomedical Corporation | Device for isolating regions of living tissue |
| US6678542B2 (en) * | 2001-08-16 | 2004-01-13 | Optiscan Biomedical Corp. | Calibrator configured for use with noninvasive analyte-concentration monitor and employing traditional measurements |
| US7045361B2 (en) | 2001-09-12 | 2006-05-16 | Medtronic Minimed, Inc. | Analyte sensing via acridine-based boronate biosensors |
| US6748254B2 (en) | 2001-10-12 | 2004-06-08 | Nellcor Puritan Bennett Incorporated | Stacked adhesive optical sensor |
| WO2003045233A1 (en) * | 2001-11-21 | 2003-06-05 | Optiscan Biomedical Corporation | Method and apparatus for improving the accuracy of alternative site analyte concentration measurements |
| US7355512B1 (en) * | 2002-01-24 | 2008-04-08 | Masimo Corporation | Parallel alarm processor |
| US7050847B2 (en) * | 2002-03-26 | 2006-05-23 | Stig Ollmar | Non-invasive in vivo determination of body fluid parameter |
| US7027848B2 (en) | 2002-04-04 | 2006-04-11 | Inlight Solutions, Inc. | Apparatus and method for non-invasive spectroscopic measurement of analytes in tissue using a matched reference analyte |
| US6654125B2 (en) | 2002-04-04 | 2003-11-25 | Inlight Solutions, Inc | Method and apparatus for optical spectroscopy incorporating a vertical cavity surface emitting laser (VCSEL) as an interferometer reference |
| US8175666B2 (en) * | 2002-04-26 | 2012-05-08 | Grove Instruments, Inc. | Three diode optical bridge system |
| US7003337B2 (en) * | 2002-04-26 | 2006-02-21 | Vivascan Corporation | Non-invasive substance concentration measurement using and optical bridge |
| US6752846B2 (en) * | 2002-07-18 | 2004-06-22 | Kohler Co. | Panel type air filter element with integral baffle |
| US7620212B1 (en) | 2002-08-13 | 2009-11-17 | Lumidigm, Inc. | Electro-optical sensor |
| CN100483106C (en) * | 2002-09-29 | 2009-04-29 | 天津市先石光学技术有限公司 | Optical method for detecting discerptible medium skin layer and deep layer information |
| US7226414B2 (en) * | 2002-10-09 | 2007-06-05 | Biotex, Inc. | Method and apparatus for analyte sensing |
| US7190986B1 (en) | 2002-10-18 | 2007-03-13 | Nellcor Puritan Bennett Inc. | Non-adhesive oximeter sensor for sensitive skin |
| US7233817B2 (en) * | 2002-11-01 | 2007-06-19 | Brian Yen | Apparatus and method for pattern delivery of radiation and biological characteristic analysis |
| CN100406872C (en) * | 2002-11-04 | 2008-07-30 | 天津市先石光学技术有限公司 | Composite spectral measurement method and its spectral detection instrument |
| US7174198B2 (en) * | 2002-12-27 | 2007-02-06 | Igor Trofimov | Non-invasive detection of analytes in a complex matrix |
| US7166458B2 (en) * | 2003-01-07 | 2007-01-23 | Bio Tex, Inc. | Assay and method for analyte sensing by detecting efficiency of radiation conversion |
| US7006856B2 (en) | 2003-01-10 | 2006-02-28 | Nellcor Puritan Bennett Incorporated | Signal quality metrics design for qualifying data for a physiological monitor |
| US7016715B2 (en) | 2003-01-13 | 2006-03-21 | Nellcorpuritan Bennett Incorporated | Selection of preset filter parameters based on signal quality |
| US20050033127A1 (en) * | 2003-01-30 | 2005-02-10 | Euro-Celtique, S.A. | Wireless blood glucose monitoring system |
| US7627151B2 (en) | 2003-04-04 | 2009-12-01 | Lumidigm, Inc. | Systems and methods for improved biometric feature definition |
| US7539330B2 (en) | 2004-06-01 | 2009-05-26 | Lumidigm, Inc. | Multispectral liveness determination |
| US7460696B2 (en) | 2004-06-01 | 2008-12-02 | Lumidigm, Inc. | Multispectral imaging biometrics |
| US7394919B2 (en) | 2004-06-01 | 2008-07-01 | Lumidigm, Inc. | Multispectral biometric imaging |
| US7147153B2 (en) | 2003-04-04 | 2006-12-12 | Lumidigm, Inc. | Multispectral biometric sensor |
| US7751594B2 (en) | 2003-04-04 | 2010-07-06 | Lumidigm, Inc. | White-light spectral biometric sensors |
| US7347365B2 (en) | 2003-04-04 | 2008-03-25 | Lumidigm, Inc. | Combined total-internal-reflectance and tissue imaging systems and methods |
| US7668350B2 (en) | 2003-04-04 | 2010-02-23 | Lumidigm, Inc. | Comparative texture analysis of tissue for biometric spoof detection |
| US7545963B2 (en) | 2003-04-04 | 2009-06-09 | Lumidigm, Inc. | Texture-biometrics sensor |
| US20040225206A1 (en) * | 2003-05-09 | 2004-11-11 | Kouchnir Mikhail A. | Non-invasive analyte measurement device having increased signal to noise ratios |
| WO2005007215A2 (en) * | 2003-07-09 | 2005-01-27 | Glucolight Corporation | Method and apparatus for tissue oximetry |
| JP4405469B2 (en) | 2003-07-22 | 2010-01-27 | 株式会社東芝 | Biological information measuring device |
| JP4089533B2 (en) * | 2003-07-28 | 2008-05-28 | 株式会社日立製作所 | Personal authentication device and blood vessel pattern extraction method |
| US7236812B1 (en) | 2003-09-02 | 2007-06-26 | Biotex, Inc. | System, device and method for determining the concentration of an analyte |
| US20050073690A1 (en) * | 2003-10-03 | 2005-04-07 | Abbink Russell E. | Optical spectroscopy incorporating a vertical cavity surface emitting laser (VCSEL) |
| US7263213B2 (en) | 2003-12-11 | 2007-08-28 | Lumidigm, Inc. | Methods and systems for estimation of personal characteristics from biometric measurements |
| US20050137469A1 (en) * | 2003-12-17 | 2005-06-23 | Berman Herbert L. | Single detector infrared ATR glucose measurement system |
| US7510849B2 (en) * | 2004-01-29 | 2009-03-31 | Glucolight Corporation | OCT based method for diagnosis and therapy |
| US20050267346A1 (en) * | 2004-01-30 | 2005-12-01 | 3Wave Optics, Llc | Non-invasive blood component measurement system |
| US20050171413A1 (en) * | 2004-02-04 | 2005-08-04 | Medoptix, Inc. | Integrated device for non-invasive analyte measurement |
| US7162288B2 (en) | 2004-02-25 | 2007-01-09 | Nellcor Purtain Bennett Incorporated | Techniques for detecting heart pulses and reducing power consumption in sensors |
| US7120479B2 (en) * | 2004-02-25 | 2006-10-10 | Nellcor Puritan Bennett Inc. | Switch-mode oximeter LED drive with a single inductor |
| US7190985B2 (en) | 2004-02-25 | 2007-03-13 | Nellcor Puritan Bennett Inc. | Oximeter ambient light cancellation |
| US7445600B1 (en) | 2004-03-01 | 2008-11-04 | Futrex, Inc. | Multi-function, self-service health kiosk |
| EA200601463A1 (en) * | 2004-03-06 | 2007-02-27 | Калисто Медикал, Инк. | METHODS AND DEVICES FOR NON-INVASIVE OBTAINING QUANTITATIVE INFORMATION ON SUBSTANCES IN LIVING ORGANISMS |
| US7194293B2 (en) | 2004-03-08 | 2007-03-20 | Nellcor Puritan Bennett Incorporated | Selection of ensemble averaging weights for a pulse oximeter based on signal quality metrics |
| US7534212B2 (en) | 2004-03-08 | 2009-05-19 | Nellcor Puritan Bennett Llc | Pulse oximeter with alternate heart-rate determination |
| US8611977B2 (en) * | 2004-03-08 | 2013-12-17 | Covidien Lp | Method and apparatus for optical detection of mixed venous and arterial blood pulsation in tissue |
| US7508965B2 (en) | 2004-06-01 | 2009-03-24 | Lumidigm, Inc. | System and method for robust fingerprint acquisition |
| US8229185B2 (en) | 2004-06-01 | 2012-07-24 | Lumidigm, Inc. | Hygienic biometric sensors |
| US20110163163A1 (en) * | 2004-06-01 | 2011-07-07 | Lumidigm, Inc. | Multispectral barcode imaging |
| US20060063991A1 (en) * | 2004-08-09 | 2006-03-23 | Dejin Yu | Method and apparatus for non-invasive measurement of blood analytes with dynamic spectral calibration |
| US20060063992A1 (en) * | 2004-08-09 | 2006-03-23 | Dejin Yu | Method and apparatus for non-invasive measurement of blood analytes |
| US20060063993A1 (en) * | 2004-08-09 | 2006-03-23 | Dejin Yu | Method and apparatus for non-invasive measurement of blood analytes |
| US8036727B2 (en) | 2004-08-11 | 2011-10-11 | Glt Acquisition Corp. | Methods for noninvasively measuring analyte levels in a subject |
| US8787630B2 (en) | 2004-08-11 | 2014-07-22 | Lumidigm, Inc. | Multispectral barcode imaging |
| US7254429B2 (en) * | 2004-08-11 | 2007-08-07 | Glucolight Corporation | Method and apparatus for monitoring glucose levels in a biological tissue |
| GB0421793D0 (en) * | 2004-10-01 | 2004-11-03 | Univ Aston | Sensing device |
| CN100522059C (en) * | 2004-10-15 | 2009-08-05 | 日本国长崎县政府 | Non-intruding measurer for value of blood sugar |
| WO2006050602A1 (en) * | 2004-11-09 | 2006-05-18 | Cybiocare Inc. | Method and apparatus for the reduction of spurious effects on physiological measurements |
| US20070207498A1 (en) * | 2005-02-24 | 2007-09-06 | Lifescan, Inc. | Design and construction of dimeric concanavalin a mutants |
| US20060247154A1 (en) * | 2005-02-24 | 2006-11-02 | Lifescan, Inc. | Concanavalin a, methods of expressing, purifying and characterizing concanavalina, and sensors including the same |
| US7761127B2 (en) | 2005-03-01 | 2010-07-20 | Masimo Laboratories, Inc. | Multiple wavelength sensor substrate |
| US7392075B2 (en) | 2005-03-03 | 2008-06-24 | Nellcor Puritan Bennett Incorporated | Method for enhancing pulse oximetry calculations in the presence of correlated artifacts |
| US20060211926A1 (en) * | 2005-03-21 | 2006-09-21 | Dejin Yu | Non-invasive Raman measurement apparatus with broadband spectral correction |
| CA2604653A1 (en) | 2005-04-13 | 2006-10-19 | Glucolight Corporation | Method for data reduction and calibration of an oct-based blood glucose monitor |
| US7801338B2 (en) * | 2005-04-27 | 2010-09-21 | Lumidigm, Inc. | Multispectral biometric sensors |
| EP1897486A1 (en) * | 2006-09-11 | 2008-03-12 | FOSS Analytical AB | Optical blood analyte monitor |
| US7657294B2 (en) | 2005-08-08 | 2010-02-02 | Nellcor Puritan Bennett Llc | Compliant diaphragm medical sensor and technique for using the same |
| US7590439B2 (en) | 2005-08-08 | 2009-09-15 | Nellcor Puritan Bennett Llc | Bi-stable medical sensor and technique for using the same |
| US7657295B2 (en) | 2005-08-08 | 2010-02-02 | Nellcor Puritan Bennett Llc | Medical sensor and technique for using the same |
| US20070060808A1 (en) * | 2005-09-12 | 2007-03-15 | Carine Hoarau | Medical sensor for reducing motion artifacts and technique for using the same |
| US8092379B2 (en) | 2005-09-29 | 2012-01-10 | Nellcor Puritan Bennett Llc | Method and system for determining when to reposition a physiological sensor |
| US7725146B2 (en) | 2005-09-29 | 2010-05-25 | Nellcor Puritan Bennett Llc | System and method for pre-processing waveforms |
| US7869850B2 (en) * | 2005-09-29 | 2011-01-11 | Nellcor Puritan Bennett Llc | Medical sensor for reducing motion artifacts and technique for using the same |
| US7725147B2 (en) | 2005-09-29 | 2010-05-25 | Nellcor Puritan Bennett Llc | System and method for removing artifacts from waveforms |
| US7899510B2 (en) | 2005-09-29 | 2011-03-01 | Nellcor Puritan Bennett Llc | Medical sensor and technique for using the same |
| US7904130B2 (en) | 2005-09-29 | 2011-03-08 | Nellcor Puritan Bennett Llc | Medical sensor and technique for using the same |
| US7486979B2 (en) | 2005-09-30 | 2009-02-03 | Nellcor Puritan Bennett Llc | Optically aligned pulse oximetry sensor and technique for using the same |
| US7555327B2 (en) | 2005-09-30 | 2009-06-30 | Nellcor Puritan Bennett Llc | Folding medical sensor and technique for using the same |
| US8233954B2 (en) | 2005-09-30 | 2012-07-31 | Nellcor Puritan Bennett Llc | Mucosal sensor for the assessment of tissue and blood constituents and technique for using the same |
| US20070106126A1 (en) | 2005-09-30 | 2007-05-10 | Mannheimer Paul D | Patient monitoring alarm escalation system and method |
| US7881762B2 (en) | 2005-09-30 | 2011-02-01 | Nellcor Puritan Bennett Llc | Clip-style medical sensor and technique for using the same |
| US7483731B2 (en) | 2005-09-30 | 2009-01-27 | Nellcor Puritan Bennett Llc | Medical sensor and technique for using the same |
| US8062221B2 (en) | 2005-09-30 | 2011-11-22 | Nellcor Puritan Bennett Llc | Sensor for tissue gas detection and technique for using the same |
| US20070100220A1 (en) | 2005-10-28 | 2007-05-03 | Baker Clark R Jr | Adjusting parameters used in pulse oximetry analysis |
| DE602006019133D1 (en) | 2005-11-30 | 2011-02-03 | Toshiba Medical Sys Corp | METHOD FOR NON-INVASIVE GLUCOSE MEASUREMENT |
| JP2007181602A (en) * | 2006-01-10 | 2007-07-19 | Norikata Taguma | Portable blood sugar level measuring instrument |
| US7668579B2 (en) | 2006-02-10 | 2010-02-23 | Lynn Lawrence A | System and method for the detection of physiologic response to stimulation |
| US20070208259A1 (en) * | 2006-03-06 | 2007-09-06 | Mannheimer Paul D | Patient monitoring alarm escalation system and method |
| US8702606B2 (en) | 2006-03-21 | 2014-04-22 | Covidien Lp | Patient monitoring help video system and method |
| US7966768B2 (en) * | 2006-05-01 | 2011-06-28 | Laminations, Inc. | Staking system for growing container |
| US8073518B2 (en) | 2006-05-02 | 2011-12-06 | Nellcor Puritan Bennett Llc | Clip-style medical sensor and technique for using the same |
| US7522948B2 (en) | 2006-05-02 | 2009-04-21 | Nellcor Puritan Bennett Llc | Medical sensor and technique for using the same |
| US7477924B2 (en) | 2006-05-02 | 2009-01-13 | Nellcor Puritan Bennett Llc | Medical sensor and technique for using the same |
| US10188348B2 (en) | 2006-06-05 | 2019-01-29 | Masimo Corporation | Parameter upgrade system |
| US8380271B2 (en) | 2006-06-15 | 2013-02-19 | Covidien Lp | System and method for generating customizable audible beep tones and alarms |
| US8175346B2 (en) | 2006-07-19 | 2012-05-08 | Lumidigm, Inc. | Whole-hand multispectral biometric imaging |
| US8355545B2 (en) | 2007-04-10 | 2013-01-15 | Lumidigm, Inc. | Biometric detection using spatial, temporal, and/or spectral techniques |
| WO2008100329A2 (en) | 2006-07-19 | 2008-08-21 | Lumidigm, Inc. | Multibiometric multispectral imager |
| US7995808B2 (en) | 2006-07-19 | 2011-08-09 | Lumidigm, Inc. | Contactless multispectral biometric capture |
| US7801339B2 (en) | 2006-07-31 | 2010-09-21 | Lumidigm, Inc. | Biometrics with spatiospectral spoof detection |
| US7804984B2 (en) | 2006-07-31 | 2010-09-28 | Lumidigm, Inc. | Spatial-spectral fingerprint spoof detection |
| US8145288B2 (en) | 2006-08-22 | 2012-03-27 | Nellcor Puritan Bennett Llc | Medical sensor for reducing signal artifacts and technique for using the same |
| US8219170B2 (en) | 2006-09-20 | 2012-07-10 | Nellcor Puritan Bennett Llc | System and method for practicing spectrophotometry using light emitting nanostructure devices |
| US8195264B2 (en) | 2006-09-22 | 2012-06-05 | Nellcor Puritan Bennett Llc | Medical sensor for reducing signal artifacts and technique for using the same |
| US8175671B2 (en) | 2006-09-22 | 2012-05-08 | Nellcor Puritan Bennett Llc | Medical sensor for reducing signal artifacts and technique for using the same |
| US8396527B2 (en) * | 2006-09-22 | 2013-03-12 | Covidien Lp | Medical sensor for reducing signal artifacts and technique for using the same |
| US7869849B2 (en) | 2006-09-26 | 2011-01-11 | Nellcor Puritan Bennett Llc | Opaque, electrically nonconductive region on a medical sensor |
| US7574245B2 (en) | 2006-09-27 | 2009-08-11 | Nellcor Puritan Bennett Llc | Flexible medical sensor enclosure |
| US7890153B2 (en) | 2006-09-28 | 2011-02-15 | Nellcor Puritan Bennett Llc | System and method for mitigating interference in pulse oximetry |
| US7796403B2 (en) | 2006-09-28 | 2010-09-14 | Nellcor Puritan Bennett Llc | Means for mechanical registration and mechanical-electrical coupling of a faraday shield to a photodetector and an electrical circuit |
| US8068891B2 (en) | 2006-09-29 | 2011-11-29 | Nellcor Puritan Bennett Llc | Symmetric LED array for pulse oximetry |
| US8175667B2 (en) | 2006-09-29 | 2012-05-08 | Nellcor Puritan Bennett Llc | Symmetric LED array for pulse oximetry |
| US8728059B2 (en) | 2006-09-29 | 2014-05-20 | Covidien Lp | System and method for assuring validity of monitoring parameter in combination with a therapeutic device |
| US8068890B2 (en) * | 2006-09-29 | 2011-11-29 | Nellcor Puritan Bennett Llc | Pulse oximetry sensor switchover |
| US7680522B2 (en) | 2006-09-29 | 2010-03-16 | Nellcor Puritan Bennett Llc | Method and apparatus for detecting misapplied sensors |
| US7684842B2 (en) * | 2006-09-29 | 2010-03-23 | Nellcor Puritan Bennett Llc | System and method for preventing sensor misuse |
| US7476131B2 (en) | 2006-09-29 | 2009-01-13 | Nellcor Puritan Bennett Llc | Device for reducing crosstalk |
| US7880626B2 (en) | 2006-10-12 | 2011-02-01 | Masimo Corporation | System and method for monitoring the life of a physiological sensor |
| DE102006056867B4 (en) * | 2006-12-01 | 2008-10-16 | Deutsche Institute für Textil- und Faserforschung Denkendorf (DITF) Institut für Textilchemie und Chemiefasern (ITCF) | Method for carrying out wastewater analyzes by means of a sensor |
| KR100859981B1 (en) * | 2007-01-19 | 2008-09-25 | 삼성전자주식회사 | Photoplethysmography sensor |
| US7894869B2 (en) * | 2007-03-09 | 2011-02-22 | Nellcor Puritan Bennett Llc | Multiple configuration medical sensor and technique for using the same |
| US8265724B2 (en) | 2007-03-09 | 2012-09-11 | Nellcor Puritan Bennett Llc | Cancellation of light shunting |
| US8280469B2 (en) | 2007-03-09 | 2012-10-02 | Nellcor Puritan Bennett Llc | Method for detection of aberrant tissue spectra |
| WO2008134135A2 (en) | 2007-03-21 | 2008-11-06 | Lumidigm, Inc. | Biometrics based on locally consistent features |
| EP2139383B1 (en) | 2007-03-27 | 2013-02-13 | Masimo Laboratories, Inc. | Multiple wavelength optical sensor |
| KR100883153B1 (en) * | 2007-04-20 | 2009-02-10 | 나가사끼-켄 | Instrument for noninvasively measuring blood sugar level |
| US8374665B2 (en) | 2007-04-21 | 2013-02-12 | Cercacor Laboratories, Inc. | Tissue profile wellness monitor |
| CN101848672A (en) * | 2007-09-13 | 2010-09-29 | 密苏里大学董事会 | Optical device components |
| EP2198268B1 (en) * | 2007-10-04 | 2022-03-16 | St. Louis Medical Devices, Inc. | Optical apparatus for determining a blood characteristic |
| US7961305B2 (en) | 2007-10-23 | 2011-06-14 | The Curators Of The University Of Missouri | Optical device components |
| US8204567B2 (en) * | 2007-12-13 | 2012-06-19 | Nellcor Puritan Bennett Llc | Signal demodulation |
| US8346328B2 (en) | 2007-12-21 | 2013-01-01 | Covidien Lp | Medical sensor and technique for using the same |
| US8352004B2 (en) | 2007-12-21 | 2013-01-08 | Covidien Lp | Medical sensor and technique for using the same |
| US8366613B2 (en) | 2007-12-26 | 2013-02-05 | Covidien Lp | LED drive circuit for pulse oximetry and method for using same |
| US8577434B2 (en) | 2007-12-27 | 2013-11-05 | Covidien Lp | Coaxial LED light sources |
| US20090171167A1 (en) * | 2007-12-27 | 2009-07-02 | Nellcor Puritan Bennett Llc | System And Method For Monitor Alarm Management |
| US8452364B2 (en) | 2007-12-28 | 2013-05-28 | Covidien LLP | System and method for attaching a sensor to a patient's skin |
| US8442608B2 (en) | 2007-12-28 | 2013-05-14 | Covidien Lp | System and method for estimating physiological parameters by deconvolving artifacts |
| US8897850B2 (en) | 2007-12-31 | 2014-11-25 | Covidien Lp | Sensor with integrated living hinge and spring |
| US8092993B2 (en) | 2007-12-31 | 2012-01-10 | Nellcor Puritan Bennett Llc | Hydrogel thin film for use as a biosensor |
| US8070508B2 (en) | 2007-12-31 | 2011-12-06 | Nellcor Puritan Bennett Llc | Method and apparatus for aligning and securing a cable strain relief |
| US8199007B2 (en) | 2007-12-31 | 2012-06-12 | Nellcor Puritan Bennett Llc | Flex circuit snap track for a biometric sensor |
| US8219169B2 (en) * | 2008-02-11 | 2012-07-10 | Glucovista Inc. | Apparatus and method using light retro-reflected from a retina to non-invasively measure the blood concentration of a substance |
| US8750953B2 (en) | 2008-02-19 | 2014-06-10 | Covidien Lp | Methods and systems for alerting practitioners to physiological conditions |
| US8275553B2 (en) | 2008-02-19 | 2012-09-25 | Nellcor Puritan Bennett Llc | System and method for evaluating physiological parameter data |
| US8768423B2 (en) | 2008-03-04 | 2014-07-01 | Glt Acquisition Corp. | Multispot monitoring for use in optical coherence tomography |
| JP2011516118A (en) * | 2008-03-25 | 2011-05-26 | ザ・キュレイターズ・オブ・ザ・ユニバーシティ・オブ・ミズーリ | Method and system for non-invasively detecting blood glucose using spectral data of one or more components other than glucose |
| US20090247851A1 (en) * | 2008-03-26 | 2009-10-01 | Nellcor Puritan Bennett Llc | Graphical User Interface For Monitor Alarm Management |
| US8140272B2 (en) * | 2008-03-27 | 2012-03-20 | Nellcor Puritan Bennett Llc | System and method for unmixing spectroscopic observations with nonnegative matrix factorization |
| US8437822B2 (en) | 2008-03-28 | 2013-05-07 | Covidien Lp | System and method for estimating blood analyte concentration |
| US8364224B2 (en) | 2008-03-31 | 2013-01-29 | Covidien Lp | System and method for facilitating sensor and monitor communication |
| US8112375B2 (en) | 2008-03-31 | 2012-02-07 | Nellcor Puritan Bennett Llc | Wavelength selection and outlier detection in reduced rank linear models |
| US8292809B2 (en) | 2008-03-31 | 2012-10-23 | Nellcor Puritan Bennett Llc | Detecting chemical components from spectroscopic observations |
| US20110004080A1 (en) * | 2008-04-11 | 2011-01-06 | Glucovista, Llc | Method for non-invasive analysis of a substance concentration within a body |
| JP5676432B2 (en) | 2008-05-22 | 2015-02-25 | ザ・キュレーターズ・オブ・ザ・ユニバーシティ・オブ・ミズーリＴｈｅ Ｃｕｒａｔｏｒｓ Ｏｆ Ｔｈｅ Ｕｎｉｖｅｒｓｉｔｙ Ｏｆ Ｍｉｓｓｏｕｒｉ | Method and system for non-invasive and optical detection of blood glucose using spectral data analysis |
| US20090327515A1 (en) * | 2008-06-30 | 2009-12-31 | Thomas Price | Medical Monitor With Network Connectivity |
| USD626562S1 (en) | 2008-06-30 | 2010-11-02 | Nellcor Puritan Bennett Llc | Triangular saturation pattern detection indicator for a patient monitor display panel |
| US7887345B2 (en) * | 2008-06-30 | 2011-02-15 | Nellcor Puritan Bennett Llc | Single use connector for pulse oximetry sensors |
| US7880884B2 (en) | 2008-06-30 | 2011-02-01 | Nellcor Puritan Bennett Llc | System and method for coating and shielding electronic sensor components |
| USD626561S1 (en) | 2008-06-30 | 2010-11-02 | Nellcor Puritan Bennett Llc | Circular satseconds indicator and triangular saturation pattern detection indicator for a patient monitor display panel |
| US8071935B2 (en) | 2008-06-30 | 2011-12-06 | Nellcor Puritan Bennett Llc | Optical detector with an overmolded faraday shield |
| US9895068B2 (en) * | 2008-06-30 | 2018-02-20 | Covidien Lp | Pulse oximeter with wait-time indication |
| US20100004518A1 (en) | 2008-07-03 | 2010-01-07 | Masimo Laboratories, Inc. | Heat sink for noninvasive medical sensor |
| US8630691B2 (en) | 2008-08-04 | 2014-01-14 | Cercacor Laboratories, Inc. | Multi-stream sensor front ends for noninvasive measurement of blood constituents |
| US8364220B2 (en) | 2008-09-25 | 2013-01-29 | Covidien Lp | Medical sensor and technique for using the same |
| US8433382B2 (en) | 2008-09-30 | 2013-04-30 | Covidien Lp | Transmission mode photon density wave system and method |
| US8417309B2 (en) | 2008-09-30 | 2013-04-09 | Covidien Lp | Medical sensor |
| US8968193B2 (en) | 2008-09-30 | 2015-03-03 | Covidien Lp | System and method for enabling a research mode on physiological monitors |
| US8386000B2 (en) | 2008-09-30 | 2013-02-26 | Covidien Lp | System and method for photon density wave pulse oximetry and pulse hemometry |
| US8914088B2 (en) | 2008-09-30 | 2014-12-16 | Covidien Lp | Medical sensor and technique for using the same |
| US8423112B2 (en) * | 2008-09-30 | 2013-04-16 | Covidien Lp | Medical sensor and technique for using the same |
| EP2365776A2 (en) * | 2008-10-31 | 2011-09-21 | Nellcor Puritan Bennett LLC | System and method for facilitating observation of monitored physiologic data |
| US8622916B2 (en) * | 2008-10-31 | 2014-01-07 | Covidien Lp | System and method for facilitating observation of monitored physiologic data |
| US8452366B2 (en) | 2009-03-16 | 2013-05-28 | Covidien Lp | Medical monitoring device with flexible circuitry |
| US8221319B2 (en) | 2009-03-25 | 2012-07-17 | Nellcor Puritan Bennett Llc | Medical device for assessing intravascular blood volume and technique for using the same |
| RU2595488C2 (en) * | 2009-04-01 | 2016-08-27 | Дзе Кьюрейторз Оф Дзе Юниверсити Оф Миссури | Optical spectroscopic device for non-invasive determination of glucose in blood and corresponding method of application |
| US8509869B2 (en) | 2009-05-15 | 2013-08-13 | Covidien Lp | Method and apparatus for detecting and analyzing variations in a physiologic parameter |
| US8634891B2 (en) | 2009-05-20 | 2014-01-21 | Covidien Lp | Method and system for self regulation of sensor component contact pressure |
| US8571619B2 (en) | 2009-05-20 | 2013-10-29 | Masimo Corporation | Hemoglobin display and patient treatment |
| US20100331640A1 (en) * | 2009-06-26 | 2010-12-30 | Nellcor Puritan Bennett Llc | Use of photodetector array to improve efficiency and accuracy of an optical medical sensor |
| US8505821B2 (en) | 2009-06-30 | 2013-08-13 | Covidien Lp | System and method for providing sensor quality assurance |
| US9010634B2 (en) | 2009-06-30 | 2015-04-21 | Covidien Lp | System and method for linking patient data to a patient and providing sensor quality assurance |
| US8311601B2 (en) | 2009-06-30 | 2012-11-13 | Nellcor Puritan Bennett Llc | Reflectance and/or transmissive pulse oximeter |
| US8391941B2 (en) | 2009-07-17 | 2013-03-05 | Covidien Lp | System and method for memory switching for multiple configuration medical sensor |
| US8494786B2 (en) | 2009-07-30 | 2013-07-23 | Covidien Lp | Exponential sampling of red and infrared signals |
| US20110034783A1 (en) * | 2009-08-10 | 2011-02-10 | Nellcor Puritan Bennett Llc | Systems and methods for balancing power consumption and utility of wireless medical sensors |
| US8417310B2 (en) | 2009-08-10 | 2013-04-09 | Covidien Lp | Digital switching in multi-site sensor |
| US8494606B2 (en) | 2009-08-19 | 2013-07-23 | Covidien Lp | Photoplethysmography with controlled application of sensor pressure |
| US8428675B2 (en) | 2009-08-19 | 2013-04-23 | Covidien Lp | Nanofiber adhesives used in medical devices |
| US8731250B2 (en) | 2009-08-26 | 2014-05-20 | Lumidigm, Inc. | Multiplexed biometric imaging |
| US8688183B2 (en) | 2009-09-03 | 2014-04-01 | Ceracor Laboratories, Inc. | Emitter driver for noninvasive patient monitor |
| US8494604B2 (en) | 2009-09-21 | 2013-07-23 | Covidien Lp | Wavelength-division multiplexing in a multi-wavelength photon density wave system |
| US8788001B2 (en) | 2009-09-21 | 2014-07-22 | Covidien Lp | Time-division multiplexing in a multi-wavelength photon density wave system |
| US8704666B2 (en) | 2009-09-21 | 2014-04-22 | Covidien Lp | Medical device interface customization systems and methods |
| US8798704B2 (en) | 2009-09-24 | 2014-08-05 | Covidien Lp | Photoacoustic spectroscopy method and system to discern sepsis from shock |
| US8923945B2 (en) * | 2009-09-24 | 2014-12-30 | Covidien Lp | Determination of a physiological parameter |
| WO2011037699A2 (en) * | 2009-09-24 | 2011-03-31 | Nellcor Puritan Bennett Llc | Determination of a physiological parameter |
| US8571621B2 (en) * | 2009-09-24 | 2013-10-29 | Covidien Lp | Minimax filtering for pulse oximetry |
| US8376955B2 (en) | 2009-09-29 | 2013-02-19 | Covidien Lp | Spectroscopic method and system for assessing tissue temperature |
| US8515511B2 (en) | 2009-09-29 | 2013-08-20 | Covidien Lp | Sensor with an optical coupling material to improve plethysmographic measurements and method of using the same |
| US9554739B2 (en) | 2009-09-29 | 2017-01-31 | Covidien Lp | Smart cable for coupling a medical sensor to an electronic patient monitor |
| US8401608B2 (en) * | 2009-09-30 | 2013-03-19 | Covidien Lp | Method of analyzing photon density waves in a medical monitor |
| US20110077470A1 (en) * | 2009-09-30 | 2011-03-31 | Nellcor Puritan Bennett Llc | Patient Monitor Symmetry Control |
| US9839381B1 (en) | 2009-11-24 | 2017-12-12 | Cercacor Laboratories, Inc. | Physiological measurement system with automatic wavelength adjustment |
| DE112010004682T5 (en) | 2009-12-04 | 2013-03-28 | Masimo Corporation | Calibration for multi-level physiological monitors |
| US9078610B2 (en) * | 2010-02-22 | 2015-07-14 | Covidien Lp | Motion energy harvesting with wireless sensors |
| US8483788B2 (en) * | 2010-02-28 | 2013-07-09 | Covidien Lp | Motion compensation in a sensor |
| US8874180B2 (en) * | 2010-02-28 | 2014-10-28 | Covidien Lp | Ambient electromagnetic energy harvesting with wireless sensors |
| US8570149B2 (en) | 2010-03-16 | 2013-10-29 | Lumidigm, Inc. | Biometric imaging using an optical adaptive interface |
| US8553223B2 (en) | 2010-03-31 | 2013-10-08 | Covidien Lp | Biodegradable fibers for sensing |
| US8391943B2 (en) | 2010-03-31 | 2013-03-05 | Covidien Lp | Multi-wavelength photon density wave system using an optical switch |
| US8428676B2 (en) | 2010-03-31 | 2013-04-23 | Covidien Lp | Thermoelectric energy harvesting with wireless sensors |
| US8498683B2 (en) | 2010-04-30 | 2013-07-30 | Covidien LLP | Method for respiration rate and blood pressure alarm management |
| US8319401B2 (en) | 2010-04-30 | 2012-11-27 | Nellcor Puritan Bennett Llc | Air movement energy harvesting with wireless sensors |
| US7884933B1 (en) | 2010-05-05 | 2011-02-08 | Revolutionary Business Concepts, Inc. | Apparatus and method for determining analyte concentrations |
| US8543354B2 (en) * | 2010-06-23 | 2013-09-24 | Medtronic Minimed, Inc. | Glucose sensor signal stability analysis |
| GB201011459D0 (en) | 2010-07-07 | 2010-08-25 | Melys Diagnostics Ltd | Optical element, assembly and method for determining analyte concentration |
| US9380982B2 (en) | 2010-07-28 | 2016-07-05 | Covidien Lp | Adaptive alarm system and method |
| US8930145B2 (en) | 2010-07-28 | 2015-01-06 | Covidien Lp | Light focusing continuous wave photoacoustic spectroscopy and its applications to patient monitoring |
| US8905927B2 (en) | 2010-11-30 | 2014-12-09 | Universal Electronics Inc. | System and method for non-intrusive health monitoring in the home |
| US8610769B2 (en) | 2011-02-28 | 2013-12-17 | Covidien Lp | Medical monitor data collection system and method |
| US9173603B2 (en) * | 2011-07-20 | 2015-11-03 | Jonathan Molcho | Non-invasive device and method for measuring bilirubin levels |
| RU2525507C2 (en) * | 2011-12-12 | 2014-08-20 | Галина Владимировна Бобылева | Method for non-invasive blood glucose test |
| US9833146B2 (en) | 2012-04-17 | 2017-12-05 | Covidien Lp | Surgical system and method of use of the same |
| CN103162829B (en) * | 2013-03-06 | 2015-02-25 | 电子科技大学 | Transmissive and reflective spectrum detection system and sensor using same |
| WO2016054079A1 (en) | 2014-09-29 | 2016-04-07 | Zyomed Corp. | Systems and methods for blood glucose and other analyte detection and measurement using collision computing |
| KR102390874B1 (en) | 2014-10-29 | 2022-04-26 | 삼성전자주식회사 | Glucose measure apparatus and method of measuring glucose thereof |
| US9554738B1 (en) | 2016-03-30 | 2017-01-31 | Zyomed Corp. | Spectroscopic tomography systems and methods for noninvasive detection and measurement of analytes using collision computing |
| US10687741B2 (en) | 2016-11-03 | 2020-06-23 | Samsung Electronics Co., Ltd. | Apparatus and method for measuring biological component |
| US10390701B2 (en) | 2016-11-17 | 2019-08-27 | Samsung Electronics Co., Ltd. | Apparatus and method for estimating biometric information |
| KR102655737B1 (en) | 2016-11-30 | 2024-04-05 | 삼성전자주식회사 | Apparatus and method for estimating substance in body |
| KR102498121B1 (en) | 2017-11-20 | 2023-02-09 | 삼성전자주식회사 | Apparatus and method for estimating bio-information |
| DE102021004609A1 (en) | 2021-09-11 | 2023-03-16 | Eques Consulting GmbH | Device and method that can be carried out with it for the non-invasive determination of the concentration of components in the human bloodstream and use of the method. |
Family Cites Families (65)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB823832A (en) * | 1956-12-22 | 1959-11-18 | Bosch Gmbh Robert | Apparatus for the calibration of a photoelectric reflection meter |
| GB977829A (en) * | 1960-09-07 | 1964-12-16 | Gilford Instr Labor Inc | Improvements in or relating to optical density analytical apparatus |
| US3154625A (en) * | 1961-01-03 | 1964-10-27 | James H Kail | Photometric method for grading beef |
| DK106165C (en) * | 1964-08-28 | 1966-12-27 | Slagteriernes Forskningsinst | Method for determining the ratio of meat to fat in a portion of meat pieces of small meat size. |
| US3463142A (en) * | 1966-07-05 | 1969-08-26 | Trw Inc | Blood content monitor |
| US3638640A (en) * | 1967-11-01 | 1972-02-01 | Robert F Shaw | Oximeter and method for in vivo determination of oxygen saturation in blood using three or more different wavelengths |
| US3638648A (en) * | 1970-02-19 | 1972-02-01 | Mine Safety Appliances Co | Breathing bags |
| US3734631A (en) * | 1971-05-28 | 1973-05-22 | Hewlett Packard Co | Nondispersive infrared gas analyzer employing solid state emitters and photodetectors |
| SU401892A1 (en) * | 1972-04-12 | 1973-10-12 | Специальное конструкторское бюро ленинградского завода Госметр | GRAIN TURKER |
| US3776642A (en) * | 1972-08-01 | 1973-12-04 | Dickey John Corp | Grain analysis computer |
| US3861788A (en) * | 1972-08-24 | 1975-01-21 | Neotec Corp | Optical analyzer for agricultural products |
| US4037970A (en) * | 1972-08-24 | 1977-07-26 | Neotec Corporation | Optical analyzer for agricultural products |
| US3910701A (en) * | 1973-07-30 | 1975-10-07 | George R Henderson | Method and apparatus for measuring light reflectance absorption and or transmission |
| US3877818A (en) * | 1974-01-28 | 1975-04-15 | Us Agriculture | Photo-optical method for determining fat content in meat |
| US3958560A (en) * | 1974-11-25 | 1976-05-25 | Wayne Front March | Non-invasive automatic glucose sensor system |
| US4029420A (en) * | 1974-12-27 | 1977-06-14 | Romilly John Simms | Light reflectance instrument |
| US4095105A (en) * | 1977-02-03 | 1978-06-13 | Neotec Corporation | Standardizing test sample |
| US4171909A (en) * | 1977-03-25 | 1979-10-23 | Miles Laboratories, Inc. | Apparatus for measuring light intensities |
| US4193116A (en) * | 1977-04-27 | 1980-03-11 | Dickey-John Corporation | Analysis instrument |
| DE2728717C2 (en) * | 1977-06-25 | 1983-11-10 | Pfister Gmbh, 8900 Augsburg | Method and device for the non-contact determination of quality features of a test object of the meat product category, in particular a carcass or parts thereof |
| US4281645A (en) * | 1977-06-28 | 1981-08-04 | Duke University, Inc. | Method and apparatus for monitoring metabolism in body organs |
| US4207466A (en) * | 1978-02-27 | 1980-06-10 | Drage David J | Infrared proximity detecting apparatus |
| US4260262A (en) * | 1978-11-28 | 1981-04-07 | Neotec Corporation | Grain quality analyzer |
| DK151393C (en) * | 1978-12-06 | 1988-05-16 | Foss Electric As N | PROCEDURE FOR QUANTITATIVE DETERMINATION OF FAT IN A WATER FAT EMULSION |
| DK167715B1 (en) * | 1978-12-08 | 1993-12-06 | Slagteriernes Forskningsinst | PROCEDURE FOR AD OPTICAL WAY TO DETERMINE THE MEAT / SPEECH RELATIONSHIP IN SUBJECTS SUCH AS ANIMAL OR PART OF ANIMALS |
| DE2918207A1 (en) * | 1979-05-05 | 1980-11-06 | Hartmann & Braun Ag | NON-DISPERSIVE INFRARED GAS ANALYZER |
| US4286327A (en) * | 1979-09-10 | 1981-08-25 | Trebor Industries, Inc. | Apparatus for near infrared quantitative analysis |
| DE3063518D1 (en) * | 1979-09-28 | 1983-07-07 | Gretag Ag | Measuring head for a densitometer |
| US4310763A (en) * | 1979-10-15 | 1982-01-12 | John Shields | Electro-optical analyzer for measuring percentage by weight of fat, protein and lactose in milk |
| US4515165A (en) * | 1980-02-04 | 1985-05-07 | Energy Conversion Devices, Inc. | Apparatus and method for detecting tumors |
| US4436207A (en) * | 1981-05-08 | 1984-03-13 | Klukis Edward L | Automatic corn sorting and inspection system |
| US4404642A (en) * | 1981-05-15 | 1983-09-13 | Trebor Industries, Inc. | Apparatus for near infrared quantitative analysis with temperature variation correction |
| US4466076A (en) * | 1981-05-15 | 1984-08-14 | Trebor Industries, Inc. | Apparatus for near infrared quantitative analysis with temperature variation correction |
| US4379233A (en) * | 1981-05-27 | 1983-04-05 | Trebor Industries, Inc. | Optical arrangement for quantitative analysis instrument utilizing pulsed radiation emitting diodes |
| US4447725A (en) * | 1981-06-15 | 1984-05-08 | Biggs Delmar A | Quantitative measurement of fat, protein and lactose in dairy products |
| US4442844A (en) * | 1981-08-28 | 1984-04-17 | Navach Joseph H | Method and apparatus for making physiological measurements |
| DE3176091D1 (en) * | 1981-09-15 | 1987-05-14 | Mueller Arno | Method and device for the quantitative determination of dissolved substances in single- or multicomponent systems of laser light scattering |
| US4484819A (en) * | 1982-06-16 | 1984-11-27 | The United States Of America As Represented By The Secretary Of The Navy | Reflectometer |
| DE3382674T2 (en) * | 1982-09-02 | 1993-07-08 | Nellcor Inc | OXYGEN MEASURING DEVICE WITH OXYGEN MEASURING PROBE. |
| US4621643A (en) * | 1982-09-02 | 1986-11-11 | Nellcor Incorporated | Calibrated optical oximeter probe |
| US4480706A (en) * | 1982-09-30 | 1984-11-06 | Trebor Industries, Inc. | Automatically determining the test weight per bushel of grain |
| US4487278A (en) * | 1983-08-24 | 1984-12-11 | Trebor Industries, Inc. | Instrument for providing automatic measurement of test weight |
| US4608990A (en) * | 1983-09-12 | 1986-09-02 | Elings Virgil B | Measuring skin perfusion |
| US4570638A (en) * | 1983-10-14 | 1986-02-18 | Somanetics Corporation | Method and apparatus for spectral transmissibility examination and analysis |
| US4768516A (en) * | 1983-10-14 | 1988-09-06 | Somanetics Corporation | Method and apparatus for in vivo evaluation of tissue composition |
| JPS60108043A (en) * | 1983-11-18 | 1985-06-13 | キヤノン株式会社 | Blood vessel position indicator |
| US4627008A (en) * | 1984-04-25 | 1986-12-02 | Trebor Industries, Inc. | Optical quantitative analysis using curvilinear interpolation |
| EP0160768B1 (en) * | 1984-05-04 | 1989-05-03 | Kurabo Industries Ltd. | Spectrophotometric apparatus for the non-invasive determination of glucose in body tissues |
| US4633087A (en) * | 1985-04-24 | 1986-12-30 | Trebor Industries, Inc. | Near infrared apparatus for measurement of organic constituents of material |
| US4692620A (en) * | 1985-05-31 | 1987-09-08 | Trebor Industries, Inc. | Near infrared measuring instrument with sample holder |
| CA1278044C (en) * | 1985-06-06 | 1990-12-18 | The Boc Group, Inc. | Hinged finger stall with light emitter and detector |
| DE3541165A1 (en) * | 1985-11-21 | 1987-05-27 | Hellige Gmbh | DEVICE FOR CONTINUOUSLY DETERMINING CONCENTRATION CHANGES IN MIXTURES |
| US4913150A (en) * | 1986-08-18 | 1990-04-03 | Physio-Control Corporation | Method and apparatus for the automatic calibration of signals employed in oximetry |
| JPS6363431A (en) * | 1986-09-04 | 1988-03-19 | ミノルタ株式会社 | Probe for oximeter |
| US4761552A (en) * | 1986-09-16 | 1988-08-02 | Trebor Industries, Inc. | Standard for near-infrared reflectance measurement and method of making the same |
| US4734584A (en) * | 1986-09-16 | 1988-03-29 | Trebor Industries, Inc. | Quantitative near-infrared measurement instrument for multiple measurements in both reflectance and transmission modes |
| US4801804A (en) * | 1986-09-30 | 1989-01-31 | Trebor Industries, Inc. | Method and apparatus for near infrared reflectance measurement of non-homogeneous materials |
| JPS63111837A (en) * | 1986-10-29 | 1988-05-17 | 日本光電工業株式会社 | Apparatus for measuring concentration of light absorbing substance in blood |
| JP2513679B2 (en) * | 1987-04-30 | 1996-07-03 | 財団法人 電気磁気材料研究所 | Ultra-high coercive force permanent magnet with large maximum energy product and method for manufacturing the same |
| JPS63311937A (en) * | 1987-06-16 | 1988-12-20 | Toshiba Corp | Endoscopic apparatus |
| US4805623A (en) * | 1987-09-04 | 1989-02-21 | Vander Corporation | Spectrophotometric method for quantitatively determining the concentration of a dilute component in a light- or other radiation-scattering environment |
| US4798955A (en) * | 1987-09-23 | 1989-01-17 | Futrex, Inc. | Measurement locator and light shield for use in interactance testing of body composition and method for use thereof |
| JPH0827235B2 (en) * | 1987-11-17 | 1996-03-21 | 倉敷紡績株式会社 | Spectroscopic method for measuring sugar concentration |
| JPH01146525A (en) * | 1987-12-02 | 1989-06-08 | Omron Tateisi Electron Co | Apparatus for noninvasive measurement of hemoglobin |
| US4882492A (en) * | 1988-01-19 | 1989-11-21 | Biotronics Associates, Inc. | Non-invasive near infrared measurement of blood analyte concentrations |
-
1989
- 1989-01-19 US US07/298,904 patent/US5028787A/en not_active Expired - Lifetime
- 1989-11-06 JP JP1288593A patent/JPH02191434A/en active Granted
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1990
- 1990-01-17 EP EP90902878A patent/EP0456716B1/en not_active Expired - Lifetime
- 1990-01-17 DE DE69032126T patent/DE69032126T2/en not_active Expired - Fee Related
- 1990-01-17 ES ES90902878T patent/ES2114860T3/en not_active Expired - Lifetime
- 1990-01-17 WO PCT/US1990/000394 patent/WO1990007905A1/en active IP Right Grant
- 1990-01-17 CA CA002045599A patent/CA2045599C/en not_active Expired - Fee Related
- 1990-01-17 AU AU50421/90A patent/AU5042190A/en not_active Abandoned
- 1990-01-17 KR KR1019900702038A patent/KR0145695B1/en not_active IP Right Cessation
- 1990-01-17 AT AT90902878T patent/ATE163844T1/en not_active IP Right Cessation
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| US5028787A (en) | 1991-07-02 |
| DE69032126D1 (en) | 1998-04-16 |
| ES2114860T3 (en) | 1998-06-16 |
| ATE163844T1 (en) | 1998-03-15 |
| EP0456716A1 (en) | 1991-11-21 |
| KR910700022A (en) | 1991-03-13 |
| CA2045599A1 (en) | 1990-07-20 |
| KR0145695B1 (en) | 1998-08-01 |
| DE69032126T2 (en) | 1998-10-15 |
| EP0456716B1 (en) | 1998-03-11 |
| JPH0558735B2 (en) | 1993-08-27 |
| AU5042190A (en) | 1990-08-13 |
| WO1990007905A1 (en) | 1990-07-26 |
| EP0456716A4 (en) | 1992-06-03 |
| JPH02191434A (en) | 1990-07-27 |
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| JPS62127669A (en) | Blood analyzing instrument |
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| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |