WO2005022203A2 - Encapsulated medical imaging - Google Patents

Abstract

An encapsulated medical imaging system comprising a capsule of swallowable proportion with at least two optical setups. Each optical setup comprises a plurality of lenses distributed in a coronal arrangement, each lens receiving light from at least a sector outside the capsule. Arrays of light sensitive cells are provided optically communicating with one of the lenses, such that the light is focused on the array of light sensitive cells. Electronic circuitry is adapted to sample image data obtained by the optical array by scanning the image and converting the image data to digital data, illuminating LED is provided for illuminating a sector in front each optical setup, outside the capsule. Transmitter communicating with the circuitry is adapted to receive data and transmit to an external receiver. The system also includes a receiver, processor, and display system.

Description

ENCAPSULATED MEDICAL IMAGING

FIELD OF THE INVENTION

The present invention relates to medical imaging. More particularly it relates to an encapsulated medical imaging device and method for imaging gastro intestinal tract in patients, using scanning technologies.

BACKGROUND OF THE INVENTION

The gastrointestinal tract in adult humans is about 7-9 meters in total. Presently, of these 7-9 meters only as much as about 1.2 meters, extending from the ends of the gastrointestinal (Gl) tract inwardly, may be imaged in commonly practiced medical imaging techniques (colonoscopy). Usually such imaging techniques involve inserting a tubular optical device (such as fiber optics) into the upper digestive system through the mouth (gastroscopy) or into the colon through the anus (colonoscopy) and advancing it along the gastrointestinal tract to inspect it and detect the presence of pathologies.

It may take years for a colon polyp to grow and turn malignant. In the absence of neurological warning system to indicate the occurrence of malignancies in their early stages it is often that the diagnosis of gastrointestinal malignancies is too late to be cured. Problems in the Gl tract are ever too often detected only when they appear in great gravity and even then detection is made possible through the discovery of secondary indications (such as fecal occult blood occurrence). Early detection can be a major factor in improving the patient's chances of survival. Some of the commonly occurring Gl diseases include Gl internal bleeding, inflammations of the Gl tract, polyps, tapering of the Gl tract, intestinal perforation, arterioveπous malformation. Internal bleeding may be caused by ulcer or varicose veins. These diseases cannot be detected in X- ray imaging or other non-invasive imaging methods until they evolve to traumatic proportion, yet even when diagnosed it is difficult to point out their exact location if that happens to fall beyond the inspectable range. Gl tract cancers are considered major factor in older adults fatalities.

Gastrointestinal malignancies are considered to be the 2^nd highest factor in male fatalities, and 3^rd highest factor in female fatalities. Gl diseases may be classified with reference to their location in the Gl tract and the distribution of these diseases was found to be as follows: 30 per cent occurring in the esophagus, stomach and duodenum, 10 per cent occurring in the small intestine and some 60 percent occurring in the large intestine.

The inability to image the small intestine may bring about the need to perform investigative abdomen incision, sometimes just for ruling out a vague suspicion of malignancy. Although some 80 per cent of the Gl diseases may supposedly be detected by colonoscopy or gastroscopy, sometimes these invasive techniques may be considered undesired. These techniques are relatively costly, requiring the presence of a several member medical team throughout the procedure. Furthermore it is statistically shown that about one in 2000 patients is prone to perforation of the Gl tract caused by a sharp object (the imaging tool) during the performance of the procedure. Such an incident immediately requires surgical intervention.

US 5,604,531 (Iddan et al.) entitled IN-VIVO VIDEO CAMERA SYSTEM, filed in 1995, and incorporated herein by reference, discloses an in- vivo video camera system and an autonomous video endoscope. The system includes a swallable capsule, a transmitter and a reception system. The swallable capsule includes a camera system and an optical system for imaging an area of interest onto the camera system. The transmitter transmits the output of the video camera system and the reception system receives the transmitted video output. US 4,278,077 (Mitzumoto) entitled MEDICAL CAMERA SYSTEM, filed in 1979, and incorporated herein by reference, discloses a capsule-shaped miniature camera comprising at least one permanent magnet, an induction coil, a lamp serially connected to the induction coil and a shutter device. The induction coil induces an electromotive force when a magnetic field generated by electromagnets outside the camera acts on it. The electromotive force turns on the lamp and drives the shutter device.

The video camera system of the '531 patent (Iddan) employs analog video and analog transmission. It is evident that it provides an image focused at a predetermined fixed distance from the optical lens and consequently, due to the poor lighting conditions within the Gl tract, blurred image of objects falling outside or falling short of the focal range. As the Gl tract is composed of parts of different diameters (the esophagus, stomach, small and large intestines) it is anticipated that substantial information will be omitted or severely degraded in the image obtained by Iddan's system. Furthermore the inside walls of the G! tract are also present "hilly" topography, and therefore pose difficulties to the imaging abilities of that system.

In PCT/IL01/00020, titled ENCAPSULATED MEDICAL IMAGING DEVICE AND METHOD (Refael), published as WO 01/50941 , there was disclosed an encapsulated medical imaging system comprising: a capsule of swallowable proportion comprising an optical setup comprising an array of microlenses distributed in axial symmetry on at least a portion of the capsule. The array of microlenses is capable of receiving light reflected from object located in at least a sector outside the capsule. Corresponding optical array comprising an array of light sensitive cells optically is communicating with the optical setup through focusing means, such that the image of the object is focused on the array of light sensitive cells; electronic circuitry adapted to sample image data obtained by the optical array by scanning the image and converting the image data to digital data; illuminating means for illuminating a sector in front the optical setup, outside the capsule; transmitting means communicating with said electronic circuitry, adapted to receive image digital data and transmit it to an external receiver; receiving means for receiving data transmitted from said capsule; image processing means for processing the data received by the receiving means and; and display means for displaying an image.

The present invention seeks to provide a novel design for a swallowable encapsulated imaging device.

BRIEF DESCRIPTION OF THE INVENTION

It is therefore thus provided, in accordance with a preferred embodiment of the present invention, an encapsulated medical imaging system comprising: a capsule of swallowable proportion comprising: at least two optical setups each comprising a plurality of lenses distributed in a coronal arrangement, each lens receiving light from at least a sector outside the capsule; arrays of light sensitive cells each optically communicating with one of the plurality of lenses, such that the light is focused on the array of light sensitive cells; electronic circuitry adapted to sample image data obtained by the optical array by scanning the image and converting the image data to digital data; illuminating means for illuminating a sector in front each optical setup, outside the capsule; transmitting means communicating with said electronic circuitry, adapted to receive image digital data and transmit it to an external receiver; receiving means for receiving data transmitted from said capsule; image processing means for processing the data received by the receiving means and; and display means for displaying an image.

Furthermore, in accordance with a preferred embodiment of the present invention, the plurality of lenses are provided behind a transparent canopy having a predetermined thickness.

Furthermore, in accordance with a preferred embodiment of the present invention, the predetermined thickness is equal or greater than the lower threshold distance of the depth of view of the lenses.

Furthermore, in accordance with a preferred embodiment of the present invention, each optical setup also comprises a front lens for front viewing. Furthermore, in accordance with a preferred embodiment of the present invention, the illumination means comprises light emitting diodes.

Furthermore, in accordance with a preferred embodiment of the present invention, the light emitting diodes illuminate light in different frequency ranges. Furthermore, in accordance with a preferred embodiment of the present invention, the light emitting diodes emit red, green or blue light.

Furthermore, in accordance with a preferred embodiment of the present invention, the light emitting diodes are operated so as to sequentially illuminate red green and blue light. Furthermore, in accordance with a preferred embodiment of the present invention, the light emitting diodes are in the form of rings. Furthermore, in accordance with a preferred embodiment of the present invention, the capsule is about 12-20 mm in length and about 5-7 mm in diameter.

Furthermore, in accordance with a preferred embodiment of the present invention, the capsule housing is made from a biocompatible material.

Furthermore, in accordance with a preferred embodiment of the present invention, the capsule housing is made from a dissolvable material.

Furthermore, in accordance with a preferred embodiment of the present invention, the capsule housing is made from a dissolvable material that is durable enough so that it may pass an entire Gl tract without disintegrating during the estimated period of time it would normally take for the capsule to pass through.

Furthermore, in accordance with a preferred embodiment of the present invention, the capsule is internally powered. Furthermore, in accordance with a preferred embodiment of the present invention, the capsule is externally powered.

Finally, in accordance with a preferred embodiment of the present invention, the capsule is inductively powered.

BRIEF DESCRIPTION OF THE FIGURES

In order to better understand the present invention, and appreciate its practical applications, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the invention as defined in the appending Claims. Like components are denoted by like reference numerals. Figure 1 illustrates a patient's Gl tract with an encapsulated medical imaging device in accordance with the present invention traveling through it.

Figure 2 illustrates a cross-sectional view of an encapsulated medical imaging device in accordance with a preferred embodiment of the present invention.

Figure 3a depicts a top view of an end of an encapsulated -medical imaging device in accordance with a preferred embodiment of the present invention.

Figure 3b depicts a top view of an end of an encapsulated medical imaging device in accordance with another preferred embodiment of the present invention.

Figure 4 illustrates fields of view of an encapsulated medical imaging device in accordance to the present invention as it travels through an intestine.

Figures 5a, 5b and 5c illustrate a display monitor communicating with a receiving unit of an encapsulated medical imaging device of the present invention incorporated in a vest worn by a patient.

Figure 6 illustrates a way to calculate the correct position of a suspected pathology detected by the encapsulated medical imaging device of the present invention.

Figure 7 illustrates an optional schematic configuration of the electronic system of an encapsulated medical imaging device in accordance with a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION AND FIGURES

A main aspect of the present invention is the provision of a novel encapsulated imaging device with two opposite optical setups for viewing large viewing sectors located facing either sides of the device. Another main aspect of the present invention is the performance of scanning of the object rather than simply taking pictures frame-by frame. The resolution of the image is determined by the number of pixels, which corresponds to the number of photosensors of a optical array utilized in the present invention. Scanning allows greater resolution to be attained in comparison with video imaging (as suggested in Iddan's '531 patent), obtaining segment-by-segment image of the viewed object.

The structure and mode of operation of the encapsulated medical imaging device of the present invention is herein explained with reference to the accompanying Figures. Reference is made to Figure 1 , illustrating a patient's Gl tract with an encapsulated medical imaging device in accordance with the present invention traveling through it. initially the patient 30 is made to swallow the capsule 1. Capsule 1 , having dimensions suitable for it to be taken orally and swallowed, after having been swallowed, immediately starts transmitting image data. It is traveling through the patient's Gl tract 35, the Gl tract generally comprising the esophagus 38, stomach 32, small intestine 34 and large intestine 36. The capsule is shown located at the small intestine 34 of the patient, traveling through it and transmitting information as it travels through. Typical anticipated dimensions for the capsule would be approximately 12 - 20 mm in length and about 5-7 mm in diameter. The capsule housing is made of bio-compatible non-toxic matter.

The encapsulated medical imaging device generally includes optical system, illumination system, optical array for obtaining digital representation of the image obtained by the optical system, electronic circuitry, and transmitting means. The electronic circuitry is externally powered or it may contain an internal power source.

The capsule advances through the Gl tract due to the normal intestinal action (contraction and relaxation of the Gl tract muscular tissue). Due to its small size the capsule leaves the body with the excrement anally.

In a preferred embodiment of the present invention the housing of the capsule is made of dissolvable material (such as the material used for producing medication capsules), so that in the event of pathological narrowing of the intestines the capsule will not be stuck there. Naturally such material should be made durable enough so that it may pass the entire Gl tract without disintegrating during the estimated period of time it would normally take for the capsule to pass through.

As it may be possible for the capsule to roll over and turn around when it advances through the Gl tract the capsule is provided with dual optics so that in fact it includes two viewing means oppositely directed. This feature is also important when the view of the front viewing optics is locally obstructed by a protrusion on the surface rising from the intestine wall (like a polyp).

The system is supplemented by external receiving unit for receiving the data transmitted from the capsule, and a control unit for processing said data and displaying the images obtained.

Figure 2 illustrates a cross-sectional view of an encapsulated medical imaging device in accordance with a preferred embodiment of the present invention.

The capsule 1 , in this example having a housing 112 of elongated dimensions, comprises two optical setups, 102a and 102 b, each having an axial hemispherical symmetry and located at either ends of the oval capsule. Each end of the capsule is provided with a front lens 116a, 116b, for viewing objects in front of that end, light emitting diodes (LED) 132, here in the form of two annular rings, for illuminating a sector in close proximity of the capsule (at least covering the whole range of the optical field of view of the optical components of the device), and an array of side lenses, directed sideways with respect to the longitudinal axis of the capsule, and covering adjacent sectors in these sides, which add up to a complete coronal view of the intestine inner wall facing the capsule adjacent the particular end of the capsule.

The optical set up on either ends of the capsule is aimed at viewing a complete coronal view of the intestine wall adjacent the capsule. For that purpose a plurality of lenses are provided, 118a, 119a, 120a, 121a on one end, and 118b, 119b, 120b and 121b on the other end (see also Fig. 3a and Fig. 3b). The lenses cover sectors that add up to the complete coronal view of the intestine wall. Optionally the field of view of the lenses may partially overlap at the borders of the filed of view to ensure complete coverage of the whole coronal view. Behind each lens an array of photosensitive cells (128a, 129a, 130a,

128b, 129b, 130b), such as CCD CMOS, is provided. Image data from the array is communicated to a central processing unit (CPU 136). The CPU transmits image data via the communication unit 138 to an external receiver for image processing and/or displaying (see also Fig. 7 and the explanation relating to it).

Optionally shutters 122 (in the form of openings in screen 124) are provided in front of some or all of the lenses, in order to control the light input thus controlling the depth of the viewing field of the lenses. The shutters may be electronically adjustable or fixed. The lenses are optionally positioned behind a transparent canopy 114a

(and corresponding transparent canopy 114b). This is done in order to distance the lenses from the intestine walls, which are very likely to be in contact with the capsule. Typically the depth of the field view of optical lenses stretches in front of the lens. Therefore, it is recommended to distance the lens from the immediate surface of the capsule so that it can provide clear and sharp image. The canopy has a predetermined thickness (which may be in the order of a few millimeters or less), which is equal or greater than the lower threshold distance of the depth of view of the lens.

Figure 3a depicts a top view of an end of an encapsulated medical imaging device in accordance with a preferred embodiment of the present invention. Figure 3b depicts a top view of an end of an encapsulated medical imaging device in accordance with another preferred embodiment of the present invention, with a front facing lens 116a.

The LED diodes 132 may optionally be sources of light in different frequencies, for example omitting light in the RGB ranges (i.e. one omitting red, another omitting green and yet another omitting blue light). This is to allow optional scanning in different monochromatic illumination by turning on separately and sequentially each LED color and then combining the different mono-chromatic gray-scale images into one color image by the processing means of the system. The light properties (such as frequency, intensity, phase) of the illuminating means are optionally controllable.

It is possible to provide the device with internal power source, such as a battery, or provide inductive circuitry (see for example US 4,278,077 to

Mitzumoto) that is powered by induction from an external inductive source. For that purpose the capsule is provided with power unit 134 and communication interface 138 (for receiving external energy).

The provision of two opposite optical setups can be appreciated by referring to Figure 4, illustrating fields of view of an encapsulated medical imaging device in accordance to the present invention as it travels through an intestine.

As the capsule arrives (position 1a) some portions of the intestine walls 39 are hidden as a protrusion 37 blocks its field of view. In fact the inside walls of the intestine are very irregular. Chyme (mixed food and digestive juices) is pushed through the small intestine through muscular contractions. During these contractions the chyme, having the consistency of runny applesauce, is squished into the lining of the wall of the small intestine. Nutrients are absorbed via osmosis by the blood vessels in the mesentery and absorbed through osmosis by the blood vessels attached to the outside of the small intestine. The lining of the intestine is hilly so as to present large surface area for that osmosis to take place. However when the capsule crosses over to position 1 b its rear optics allows viewing that hidden area and thus the limitations of the prior art devices concerning their field of view is greatly reduced. It is clearly seen that the capsule may be positioned in different distances 31 , 33, 29, 51 ) from the intestine wall lining, due to the depth of field of the lenses.

Figures 5a, 5b and 5c illustrate a display monitor communicating with a receiving unit of an encapsulated medical imaging device of the present invention incorporated in a vest 21 worn by a patient. Vest 21 houses the receiving unit adapted to communicate with the capsule and may also include powering means such as inductive circuitry. It engulfs the patients' torso effectively close to the capsule as it travels through the patient's Gl tract. The receiving unit in the vest communicates via cable or wirelessly with monitoring unit 139. Monitoring unit 139 provided with display means for displaying one or several images 17, 18, by the encapsulated medical imaging device and/or other data 16.

Figure 6 illustrates the path traveled by a capsule in a patient's small intestine. In another preferred embodiment of the present invention the device incorporates with monitoring means adapted to identify the position and location within the Gl tract where an image was acquired by comparing it to a prearranged library of images, and identifying by image processing the type of environment the capsule was in when the image was acquired. It is stipulated that each portion of the Gl track (i.e. esophagus, small intestine, large intestine stomach) has unique image (texture, shape, and other distinct features). By identifying the type of environment the device was in when the image was acquired and by knowing some parameters such as the sampling rate of the device, its traveling velocity within the Gl tract (on average it is assumed that it would travel at the rate of 1 to 3 cm per second) it is possible to determine or at least estimate the distance of the path 94 traveled by the capsule from the last identified position 92 to the current location 96, where a pathology was detected and viewed by the capsule. The software may generate a general view of the Gl tract, the last image obtained as the device entered into the current type of Gl tract and most recent image obtained. A graphic indication on the general image, in the form of a cursor, arrow or any other graphical representation, may be superposed on the Gl tract image indicating the device current (or recent) location. This can substantially enhance the medical team's ability to locate the exact position of the pathology found in position 96. Figure 7 illustrates an optional schematic configuration of the electronic system of an encapsulated medical imaging device in accordance with a preferred embodiment of the present invention. This is given as an example only. A person skilled in the art could easily provide other electrical configurations that would still be covered by the scope of the present invention.

The capsule 200 generally comprises optics 110 (the lenses) communicating with a control unit 212 that transmits the digital data obtained from the optical array via communication interface 214 and antenna 216. The capsule is optionally inductively powered by an inductive circuitry 211 energized externally by inductance. A receiver 202 (such as one incorporated in a vest - see Figures 5b and 5c) picks up the data transmitted by an antenna 118 and communicates with a control unit 104. The control unit comprises communication interface 120, control unit 122, processor 224, and display means 226 (such as a monitor). It is optionally also provided with a user interface 228, for inputting commands to the control unit. In a preferred embodiment of the present invention the control unit is programmed or programmable so that physician can adjust the sampling rate of the device (i.e. the frequency of image acquiring), control the foldable arms, choose the images to be displayed or command the system to perform calculations (such as the distance traveled by the capsule inside the intestine). The advantages of the encapsulated imaging device of the present invention are numerous. The device provides high accessibility to the entire Gl tract. The unique optical setup provides better images and a greater range for focused images. Optional sampling arms may be operated in-vivo and obtain samples such as biopsy, blood test or retrieve any other sample from the matter the device comes near to. External energizing prevents the need for internal power source that may be hazardous to the patient if the capsule disintegrates within the Gl tract.

In a preferred embodiment of the present invention the images may be obtained by scanning in RGB light - first scanning in red light, then scanning in green and finally in blue, each time obtaining mono-chromatic gray-scale quality images and incorporating them into a color image by the processing means of the external unit and presenting the color image on the monitor.

Note that the system described in the specification and figures is mainly designed to obtain black and white images, but these images are remarkably clear and distinct and the anticipated resolution is much greater than that of video images.

It should be clear that the description of the embodiments and attached Figures set forth in this specification serves only for a better understanding of the invention, without limiting its scope as covered by the following Claims. It should also be clear that a person skilled in the art, after reading the present specification could make adjustments or amendments to the attached Figures and above described embodiments that would still be covered by the following Claims.

Claims

C L A I M S

1. An encapsulated medical imaging system comprising: a capsule of swallowable proportion comprising: at least two optical setups each comprising a plurality of lenses distributed in a coronal arrangement, each lens receiving light from at least a sector outside the capsule; arrays of light sensitive cells each optically communicating with one of the plurality of lenses, such that the light is focused on the array of light sensitive cells: electronic circuitry adapted to sample image data obtained by the optical array by scanning the image and converting the image data to digital data; illuminating means for illuminating a sector in front each optical setup, outside the capsule; transmitting means communicating with said electronic circuitry, adapted to receive image digital data and transmit it to an external receiver; receiving means for receiving data transmitted from said capsule; image processing means for processing the data received by the receiving means and; and display means for displaying an image.

2. The system as claimed in Claim 1 , wherein the plurality of lenses are provided behind a transparent canopy having a predetermined thickness.

3. The system as claimed in Claim 2, wherein the predetermined thickness is equal or greater than the lower threshold distance of the depth of view of the lenses.

4. The system as claimed in Claim 1 , wherein each optical setup also comprises a front lens for front viewing.

5. The system as claimed in Claim 1 , wherein the illumination means comprises light emitting diodes.

6. The system as claimed in Claim 5, wherein the light emitting diodes illuminate light in different frequency ranges.

7. The system as claimed in Claim 6, wherein the light emitting diodes emit red, green or blue light.

8. The system as claimed in claim 7, wherein the light emitting diodes are operated so as to sequentially illuminate red green and blue light.

9. The system as claimed in claim 5 wherein the light emitting diodes are in the form of rings.

10. The system as claimed in Claim 1 , wherein the capsule is about 12-20 mm in length and about 5-7 mm in diameter.

11. The system as claimed in claim 1 , wherein the capsule housing is made from a biocompatible material.

12. The system as claimed in Claim 1 , wherein the capsule housing is made from a dissolvable material.

13. The system as claimed in Claim 12, wherein the capsule housing is made from a dissolvable material that is durable enough so that it may pass an entire Gl tract without disintegrating during the estimated period of time it would normally take for the capsule to pass through.

14. The system as claimed in Claim 1 , wherein the capsule is internally powered.

15. The system as claimed in Claim 1 , wherein the capsule is externally powered.

16. The system as claimed in Claim 15, wherein the capsule is inductively powered.