US20050259487A1 - In vivo imaging device with a small cross sectional area - Google Patents

Abstract

An image sensor (e.g., a CMOS sensor) includes a pixel array portion and a circuitry portion, where the circuitry portion may be segregated, for example longitudinally, from the pixel array portion.

Description

BACKGROUND OF THE INVENTION
• Devices and methods for performing in-vivo imaging of passages or cavities within a body are known in the art. Such devices may include, inter alia, various endoscopic imaging systems and devices for performing imaging in various internal body cavities.
• Reference is now made toFIG. 1 which is a schematic diagram illustrating an embodiment of an autonomous in-vivo imaging device. Thedevice10A typically includes a capsule-like housing18 having awall18A. Thedevice10A has anoptical window21 and an imaging system for obtaining images from inside a body cavity or lumen, such as the GI tract. The imaging system may include anillumination unit23. Theillumination unit23 may include one or morelight sources23A. The one or morelight sources23A may be a white light emitting diode (LED), or any other suitable light source, known in the art. The imaging system of thedevice10A may include animager24, such as a CMOS or CCD, which acquires the images and anoptical system22 which focuses the images onto theimager24. Typically, theimager24 is arranged so that it'ssurface27 is perpendicular to thelongitudinal axis19 of thedevice10A. Theillumination unit23 illuminates the inner portions of the body lumen through anoptical window21.Device10A further includes atransmitter26 and anantenna27 for transmitting the image signal of theimager24, and one ormore power sources25. The power source(s)25 may be any suitable power sources such as but not limited to silver oxide batteries, lithium batteries, or other electrochemical cells having a high energy density, or the like. The power source(s)25 may provide power to the electrical elements of thedevice10A.
• Typically, in the gastrointestinal application, as thedevice10A is transported through the gastrointestinal (GI) tract, the imager, such as but not limited to a multi-pixel CMOS imager acquires images (frames) which are processed and transmitted to an external receiver/recorder (not shown) worn by the patient for recording and storage. The recorded data may then be downloaded from the receiver/recorder to a computer or workstation (not shown) for display and analysis. During the movement of thedevice10A through the GI tract, the imager may acquire frames at a fixed or at a variable frame acquisition rate. For example, in one embodiment the imager (such as, but not limited to a CMOS Imager) may acquire images at a fixed rate of two frames per second (2 Hz). However, other different frame rates may also be used, depending, inter alia, on the type and characteristics of the specific imager or camera or sensor array implementation which is used, and on the available transmission bandwidth of thetransmitter26. The downloaded images may be displayed by the workstation by replaying them at a desired frame rate. This way, the expert or physician examining the data is provided with a movie-like video playback which may enable the physician to review the passage of the device through the GI tract.
• It may generally be desirable to decrease the size and particularly the cross sectional area of in vivo imaging devices, such as thedevice10A ofFIG. 1, or of imaging devices that are to be inserted into working channels of endoscope-like devices, or integrated into catheter-like devices which may be used in conjunction with guide wires, or the like. Smaller catheter like devices with reduced area may be inserted into narrower body cavities or lumens, such as for example, the coronary arteries, the urethra, the common bile duct, or the like and may also be easier to insert into working channels of other devices such as endoscopes, laparoscopes, gastroscopes, or the like.
• Decreasing the cross-sectional area of such devices may be limited by the cross-sectional area of the imaging sensor, such as for example theimager24 ofFIG. 1
SUMMARY OF THE INVENTION
• In one embodiment, an image sensor (e.g., a CMOS sensor) includes a pixel array portion and a circuitry portion, where the circuitry portion may be segregated, for example longitudinally, from the pixel array portion.
BRIEF DESCRIPTION OF THE DRAWINGS
• The invention is herein described, by way of example only, with reference to the accompanying drawings, in which like components are designated by like reference numerals, wherein:
• FIG. 1 is a schematic diagram illustrating an embodiment of a prior art autonomous in-vivo imaging device;
• FIG. 2 is a schematic front view of the surface layout of a typical prior art CMOS imager.
• FIG. 3 is a schematic front view of theimager24 ofFIG. 1;
• FIG. 4 is a schematic cross sectional view illustrating a CMOS imager having a square cross-sectional area disposed within a housing having a circular cross-section;
• FIG. 5 is a schematic top view showing the layout of a rectangular CMOS imager having segregated pixel array area and support circuitry areas, in accordance with a preferred embodiment of the present invention;
• FIG. 6 is a cross-sectional view illustrating an in-vivo imaging device having a reduced cross-sectional area and including the CMOS imager ofFIG. 5, in accordance with a preferred embodiment of the present invention;
• FIG. 7 is a cross-sectional view illustrating an in-vivo imaging device having a reduced cross-sectional area and including the CMOS imager ofFIG. 5, in accordance with another preferred embodiment of the present invention; and
• FIG. 8 is a schematic cross sectional view of part of an insertable device for in vivo imaging, in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
• In the following description, various aspects of the present invention will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the present invention. However, it will also be apparent to one skilled in the art that the present invention may be practiced Without the specific details presented herein. Furthermore, well known features may be omitted or simplified in order not to obscure the present invention.
• The present invention is based on providing an imager having a small cross-sectional area for implementing in vivo imaging devices such as, but not limited to, swallowable autonomous in-vivo imaging devices (capsule-like or shaped otherwise), and wired or wireless imaging units which are integrated into endoscope-like devices, catheter-like devices, or any other type of in-vivo imaging device that can be introduced into a body cavity or a body lumen.
• It is noted that while the embodiments of the invention shown hereinbelow are adapted for imaging of the gastrointestinal (GI) tract, the devices and methods disclosed may be adapted for imaging other body cavities or spaces.
• FIG. 2 is a schematic front view of the surface layout of a typical prior art CMOS imager. TheCMOS imager30 is an integrated circuit, which is typically implemented on a silicon wafer. TheCMOS imager30 includes animaging sensor part30A which is usually located at one of the corners of the frontal surface of theCMOS imager30. Theimaging sensor part30A may include the two dimensional array of light sensitive diodes (not shown in detail) comprising the sensor pixels (not shown in detail), and may also include integrated amplification circuitry (not shown) and switching circuitry (not shown) for controlling the pixel sampling or readout, and may also include electrical con ducting paths for connecting the pixels to the functional units that perform the readout of the pixels.
• Theremaining surface portion30B of theCMOS imager30, may include, inter alia, integrated circuitry (not shown in detail) for performing various control and timing functions, analog to digital (A/D) conversion circuitry (not shown) for converting the analog signal sampled from the individual pixels and various input/output (I/O) circuitry (not shown in detail) for sending the image digitized data and control signals as output signals to devices or circuitry (not shown) such as but not limited to a transmitter like thetransmitter26 ofFIG. 1, or any other signal processing circuit or element or unit which may be connected to theCMOS imager30, as is known in the art.
• Reference is now made toFIG. 3 which is a schematic front view of theimager24 ofFIG. 1. Theimager24 ofFIG. 1 may be a CMOS imager and may be configured to have a square shape having a side length S (as seen in the front view ofFIG. 3).
• TheCMOS imager24 may include animaging sensor part24A which may be typically located at the center of the frontal surface of theCMOS imager24. Theimaging sensor part24A may include the two dimensional array of light sensitive diodes (not shown in detail) comprising the sensor pixels (not shown in detail), and may also include integrated amplification circuitry (not shown) and switching circuitry (not shown) for controlling the pixel sampling or readout, and may also include electrical conducting paths for connecting the pixels to the functional units that perform the readout of the pixels.
• Theremaining surface portion24B of the of theCMOS imager24, which surrounds theimaging sensor part24A, may include, inter alia, integrated circuitry (not shown in detail) for performing various control and timing functions, analog to digital (A/D) conversion circuitry (not shown) for converting the analog signal sampled from the individual pixels and various input/output (I/O) circuitry (not shown in detail) for sending the image digitized data and control signals as output signals to devices or circuitry (not shown) such as but not limited to a transmitter like thetransmitter26 ofFIG. 1, or any other signal processing circuit or element or unit which may be connected to theCMOS imager24.
• The advantage of the imager configuration shown inFIG. 3, is that it makes possible to position the optical system22 (best seen inFIG. 1) in the center of the optical window21 (seeFIG. 1) without unduly increasing the cross-sectional area of theentire device10A ofFIG. 1). However, with the configuration (shown inFIG. 3) of theCMOS imager24, if it is desired to minimize the cross-sectional area of thedevice10A, the diminishing of the cross-sectional area of theentire device10A may be limited by the diagonal of theentire CMOS imager24.
• Reference is now made toFIG. 4 which is a schematic cross sectional view illustrating a CMOS imager having a square cross-sectional area disposed within a housing having a circular cross-section.
• TheCMOS imager24 is shown disposed within ahousing28 having awall28A. Thehousing28 has a circular cross-section. Thewall28A may be part of a capsule like housing, such as thehousing18 shown in the capsule-like device10A ofFIG. 1). Thewall28A may also be the wall of an imaging unit which comprises part of an elongated device such as a catheter-like device (not shown), or an endoscope-like device (not shown) or the like.
• Similar to theCMOS imager24 ofFIG. 3, thesquare CMOS imager34 ofFIG. 4 may have a squareimaging sensor part34A (having a side length of A_l) including the imaging pixels (the pixels are not shown in detail) and aremaining surface part34B which surrounds theimaging sensor part34A and which may include all the supporting circuitry (not shown) as disclosed in detail hereinabove for thesurface part24B ofFIG. 3. Theentire CMOS imager34 has a side S, and diagonal D. It can be seen fromFIG. 4 that the internal diameter of thewall28A of thehousing28 may not be smaller than the length of the diagonal D of thesquare CMOS imager34. Thus, using the configuration of theCMOS imager34, it is not possible to decrease the diameter of thehousing28 to a length smaller than the diagonal D of theentire CMOS imager34.
• Reference is now made toFIG. 5 which is a schematic top view showing the layout of a rectangular CMOS imager having segregated pixel array area and support circuitry areas, in accordance with a preferred embodiment of the present invention. TheCMOS imager54 may include a squareimaging sensor part54A (having a side length of A_l) including the imaging pixels (the pixels are not shown in detail) and a remainingsurface part54B which is longitudinally segregated from theimaging sensor part54A and which may include all the necessary supporting circuitry (not shown) as disclosed in detail hereinabove.
• The length L_lof theCMOS imager54 is adapted such that all the necessary supporting circuitry may be accommodated in thepart54B. Thus, when theCMOS imager54 is compared to theCMOS imager34 ofFIG. 4, the dimensions of theimaging sensor parts34A and54A are the same (both imaging sensor parts may be a square having a side length of A_l), theCMOS imager34 has a square shape-having a side S, while theCMOS imager54 has an elongated shape having a length L₁.
• Reference is now made toFIG. 6 which is a cross-sectional view illustrating an in-vivo imaging device having a reduced cross-sectional area and including the CMOS imager ofFIG. 5, in accordance with a preferred embodiment of the present invention.
• Thedevice50 includes a capsule-like housing58 which has anoptical window21A. Thedevice50 may include anoptical system22A and amirror55. Thedevice50 may include theCMOS imager54 ofFIG. 5. Themirror55 may be substituted by any suitable light deflecting element such as a suitably configured prism, or the like, for deflecting the light rays collected by the22A optical system towards thepart54A of theCMOS imager54. Theoptical system22A may be a lens, a group of lenses, a zoom lens, a composite lens, a wide angle lens or any other suitable image forming optical element known in the art.
• Thedevice50 further includes thepower sources25A which may be similar to thepower sources25 ofFIG. 1 but may be smaller in size due to the reduced cross sectional area of thedevice50. Thedevice50 also includes an illuminatingunit53 comprising thelight sources53A. The construction and operation of the illuminatingunit53 and thelight sources53A may be as disclosed in detail for the illuminatingunit23 and thelight sources23A ofFIG. 1, and possibly, as disclosed in WO 01/65995. Thedevice50 may also include awireless transmitter26A and anantenna27A for transmitting the data of the acquired images.
• TheCMOS imager54 is disposed longitudinally within thehousing58 such that the light rays47 generated by thelight sources53A are reflected from the intestinal wall and pass through theoptical window21A. The reflected light rays are collected by theoptical system22A and are deflected towards thepart54A of theCMOS imager54 to create an image to be sensed by the light sensing pixels (not shown) included in thepart54A. Preferably, but not necessarily, theCMOS imager54 is disposed such that its longitudinal axis (not shown) is aligned parallel to thelongitudinal axis59 of thedevice50. The angle α between the surface of themirror55 and the surface of the CMOS imager may be 45°, but may also be smaller than 45°. If the angle α is smaller than 45°, the image projected upon the pixels of thepart54A of theCMOS imager54 may be distorted. Thus, theoptical system22A may be configured to suitably change the collected image in order to compensate for the distortion before the image reaches thepart54A of theCMOS imager54. Alternatively, the distortion in the acquired image may be corrected after the acquisition by suitably processing the image data at a stage later than image acquisition. For example a distorted image may be processed in a workstation (not shown) after the image has been transmitted by thetransmitter26A. Such a distortion may be compensated by suitable computational algorithms, as is known in the art.
• It is noted that in comparison to the configuration of theCMOS imaging unit24 ofFIG. 1 and theCMOS imaging unit34 ofFIG. 4 which are oriented perpendicular the longitudinal axis of the invivo imaging device10A, the configuration of theCMOS imager54 being longitudinal and parallel to theaxis59 of thedevice50 may enable a substantial reduction in the cross sectional area of thedevice50 since the combination of the reduced area of the lightsensitive part54A and the use of themirror55 allow such a reduction in cross-sectional area. It is noted that the cross sectional area (Ai)²of thepart54A ofFIG. 6 is substantially smaller than the cross sectional area (D)2 of theentire CMOS imager34 ofFIG. 4. The cross-sectional area of a cross section taken in a direction perpendicular to the longitudinal axis thedevice50 may therefore be substantially reduced in comparison to the cross sectional area of a cross section taken in a direction perpendicular to thelongitudinal axis19 of thedevice10A.
• It is noted that additional configurations of the optical components of the in vivo imaging device may be possible.
• Reference is now made toFIG. 7 which is a cross-sectional view illustrating an in-vivo imaging device having a reduced cross-sectional area and including the CMOS imager ofFIG. 5, in accordance with another preferred embodiment of the present invention.
• Thedevice60 includes a capsule-like housing58 which has anoptical window21A. Thedevice60 may include anaperture51, anoptical system65A and amirror55. Thedevice60 may include theCMOS imager54 ofFIG. 5. Themirror55 may be substituted by any suitable light deflecting element such as a suitably configured prism (not shown), or the like, for deflecting the light rays47C passing through by theaperture51, towards theoptical system65A which projects an image on thepart54A of theCMOS imager54. Theoptical system65A may be a lens, a group of lenses, a zoom lens, a composite lens, a wide angle lens or any other suitable image forming optical element known in the art.
• Thedevice60 further includes thepower sources25A which may be similar to thepower sources25A ofFIG. 6.
• TheCMOS imager54 is disposed longitudinally within thehousing58 such that thelight rays47A and47B generated by thelight sources53A are reflected from theintestinal wall45 and pass through theoptical window21A aslight rays47C and47D, respectively. The reflectedlight rays47C and47D are deflected by themirror55 towards theoptical system22A. Theoptical system65A thus focuses an image on thepart54A of theCMOS imager54 the image may be sensed by the light sensing pixels (not shown) included in thepart54A. Preferably, but not necessarily, theCMOS imager54 is disposed such that its longitudinal axis (not shown) is aligned parallel to thelongitudinal axis69 of thedevice60. The angle a between the surface of themirror55 and the surface of the CMOS imager may be 45°, but may also be smaller than 45°.
• If the angle α is smaller than 45°, the image projected upon the pixels of thepart54A of theCMOS imager54 may be distorted. Thus, theoptical system65A may be configured to suitably change the collected image in order to compensate for the distortion before the image reaches thepart54A of theCMOS imager54. Alternatively, the distortion in the acquired image may be corrected after the acquisition by suitably processing the image data at a stage later than image acquisition. For example, a distorted image may be processed in a workstation (not shown) after the image has been transmitted by thetransmitter26A. Such a distortion may be compensated by suitable computational algorithms, as is known in the art.
• The configuration of theimager54 and themirror55 and theoptical system65A of thedevice60 may also enable thedevice60 to have a reduced cross sectional area for the reasons disclosed in detail hereinabove.
• Thus, the combination of the CMOS imager having segregated imaging and support circuitry parts disclosed hereinabove, and the longitudinal arrangement of such a segregated CMOS imager within the device allow the construction of autonomous or non-autonomous in vivo imaging devices with a small cross sectional area. The non-autonomous devices may include but are not limited to imaging heads or imaging units or imaging assemblies which are constructed as an integral part of, or are included within ,or-are attached to catheter like devices, endoscope-like devices, trocars, or any other type of device which may be used for in vivo surgical and/or diagnostic purposes requiring imaging capabilities and may benefit from the reduced cross-sectional area of such imaging heads or imaging units or imaging assemblies.
• Reference is now made toFIG. 8 which is a schematic cross sectional view of part of an insertable device for in vivo imaging, in accordance with a preferred embodiment of the present invention.
• Theinsertable device80 may include an elongated (preferably flexible)housing78. Thehousing78 may have anoptical window21A sealingly attached at theend80A thereof. Thedevice80 may further include theCMOS imager54 which is arranged longitudinally within thehousing78. TheCMOS imager54 has an imaging lightsensitive part54A segregated from othersupport circuitry part54B as disclosed in detail hereinabove with respect toFIGS. 5-7.
• Thedevice80 may include amirror55 which is inclined at an angle α to theimaging part54A of theCMOS imager54, as disclosed hereinabove. The angle α may be equal to 45° or may be different than 45°. Making the angle α smaller than 45°, may enable further reduction of the diameter or the cross sectional area of thedevice80 as disclosed hereinabove for thedevices50 and60. Anoptical system22C may be suitably aligned along thelongitudinal axis89 of thedevice80. Theoptical system22C may include a single lens, multiple lenses, or other suitable optical elements like filters, as disclosed in detail hereinabove for theoptical systems22,22A and65A ofFIGS. 1,6 and7, respectively.
• Thedevice80 may include anillumination unit23H which may includelight sources23B. Thelight sources23B may be the while LED light sources disclosed in detail hereinabove, and possibly, as disclosed in WO 01/65995., but may also be any other suitable miniature light sources known in the art. TheCMOS imager54 may be connected to asuitable power source85 by suitable electrically conductingwires92 connected to thepower source85. TheCMOS imager54 may be connected to suitable electrically conductingwires82 for transmitting the image data to an external device (not shown) for further processing and for displaying of the acquired images.
• It is noted that in accordance with another preferred embodiment of the present invention, the image data may be transmitted wirelessly to a receiver or a receiver/recorder, as is disclosed in detail for the autonomous invivo imaging device10A, and possibly, as disclosed in WO 01/65995. In such a case thedevice80 may include an internal power source, a wireless-transmitter (such as but not limited to thetransmitters26 or26A ofFIGS. 1, 6 and7) and an antenna (such as but not limited to theantenna27 of thedevice10A).
• Thelight sources23B may be connected to thepower source85 by suitable electrically conductingwires90 disposed within thehousing78. Alternatively, thelight sources23B may receive power and may be controlled by being coupled to the CMOS imager54 (connections are not shown).
• Thepower source85 may be any suitable electrical power source, including but not limited to a mains operated power source, a battery, or the like. Alternatively, thepower source85 may be disposed within the housing78 (not shown).
• Other alternative designs of the optical arrangement in thedevice80 may also be used. For example, thedevice80 may have an optical aperture (such as, for example, theoptical aperture51 ofFIG. 7) and an optical system (such as, for example, theoptical system65A ofFIG. 7) disposed between thepart54A of theCMOS imager54 and themirror55.
• If the angle α is smaller than 45°, and a correction is needed for the distortion in the image, the distortion may be corrected by theoptical system22C (or by the optical system disposed between thepart54A of theCMOS imager54 and themirror55, if the alternative optical arrangement is being used). Alternatively, image distortion may be corrected computationally by suitably processing the image data in a post-acquisition step, as is known in the art.
• The segregated circuitry design of theCMOS imager54 and the use of themirror55, enable the reduction of the transverse cross sectional area of thedevice80 as explained in detail hereinabove for thedevices50 and60 ofFIGS. 6 and 7 respectively.
• It is noted that, for the sake of simplicity of illustration, theinsertable device80 is illustrated as having imaging capabilities only. Thedevice80 may for example be inserted into a working channel of an endoscope (not shown) and may be used for insertion into and imaging of narrow cavities into which the endoscope cannot be inserted. However, Thedevice80 itself may include one or more working channels (not shown inFIG. 8 for the sake of clarity of illustration). The working channels may be used for performing insufflation and/or irrigation as is known in the art. Additionally, one or more instruments may be inserted into such working channels for performing a variety of surgical operations. Such instruments may includes but are not limited to scissors, other surgical blades, wire snares, banding devices, surgical laser devices, cauterizers, or any other surgical or diagnostic instrument known in the art and insertable through such a working channel. Thus, if thedevice80 includes one or more working channels, thedevice80 may be operated as an endoscopy device as is known in the art.
• While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made which are within the scope and spirit of the invention.

Claims (8)

1. A CMOS image sensor comprising a pixel array portion and a circuitry portion, said circuitry portion being longitudinally segregated from the pixel array portion.

2. The CMOS image sensor according toclaim 1 wherein the pixel array portion is continuous with the circuitry portion.

3. The CMOS image sensor according toclaim 1 wherein the circuitry portion comprises circuitry selected from the group consisting of timing circuitry, analog to digital conversion circuitry, input/output (I/O) circuitry, transmitting circuitry or a combination thereof.

4. An in vivo imaging device comprising:

a housing having a longitudinal axis, said housing accommodating a CMOS image sensor according toclaim 1, said image sensor disposed substantially parallel to the longitudinal axis of the housing; and

a light deflecting element positioned to intercept reflected light and configured to deflect the reflected light to the pixel array.

5. The device according toclaim 4 wherein the light deflecting element is positioned at substantially 45° to the pixel array.

6. The device according toclaim 4 wherein the light deflecting element is a mirror.

7. The device according toclaim 4 further comprising an optical system, said system configured for changing an image to compensate for distortion of an image by the light deflecting element.

8. The device according toclaim 4 further comprising an aperture for reflected light to progress through.

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