JP5153487B2 - Capsule medical device - Google Patents

Description

  The present invention relates to a capsule medical device that is introduced into an organ of a subject and images an image inside the organ (hereinafter also referred to as an in-vivo image).

  Conventionally, in the medical field, a swallowable capsule medical device having an imaging function and a wireless communication function has appeared. In general, a capsule medical device is swallowed from the mouth of a subject for observation (examination) inside the subject, and then moves inside the digestive tract of the subject by peristaltic movement or the like, while in-vivo images of the subject Are sequentially imaged. In this case, the capsule medical device emits illumination light to illuminate the inside of the organ, and captures an image inside the illuminated organ, that is, an in-vivo image. The capsule medical device wirelessly transmits the in-vivo image thus captured to the outside of the subject. Such a capsule medical device sequentially repeats in-vivo image capturing and wireless transmission of the subject until it is discharged to the outside of the subject.

  The in-vivo image wirelessly transmitted from the capsule medical device is received by a receiving device outside the subject and accumulated in a storage medium in the receiving device. This storage medium is removed from the receiving device after the in-vivo image group of the subject is accumulated, and is inserted into the image display device. The image display device takes in the in-vivo image group in the inserted storage medium and sequentially displays the obtained in-vivo image group on the display. A user such as a doctor or a nurse can diagnose a subject by observing the in-vivo image group displayed on the image display device.

  In such a capsule medical device, for example, the axial center of the amount of illumination light emitted from the light emitter is shifted outward, and the brightness of the illumination light in the observation center portion and the illumination in the peripheral portions other than the observation center portion Some have the light brightness substantially the same (see Patent Document 1), and others have the light beam shape adjustment unit uniform the illuminance in the entire field of view of the imaging apparatus (see Patent Document 2).

  On the other hand, the subject image formed on the image sensor is divided into a plurality of areas, and the overall luminance value of the subject image is calculated by multiplying the partial luminance value of each of the plurality of areas by a corresponding weighting coefficient. If there is an electronic endoscope apparatus (see Patent Document 3) that adjusts the brightness of the subject image by changing the aperture according to the difference between the overall luminance value and the reference luminance value, the luminance pixel signal for one frame from the image sensor There is also an electronic endoscope apparatus (see Patent Document 4) that develops a histogram based on the above and adjusts the amount of light guided from the light source to the scope based on the histogram. In addition, an endoscope apparatus that allows a plurality of types of LED bare chips of different shapes or sizes to be disposed on a mounting base that is integrally provided in the insertion portion, and that achieves both a reduction in the size of the insertion portion and a sufficient amount of light (Patent Document) 5) If it exists, the electronic endoscope apparatus which makes the brightness of the to-be-photographed object image displayed on a screen appropriate by determining the light quantity of the light which injects into an optical fiber according to the shape of an observation part (patent document 6) There is also.

International Publication No. 2004/096029 Pamphlet JP 2007-181669 A JP 2003-180631 A JP 2000-81577 A JP 2005-342299 A JP 2002-159445 A

  By the way, the above-described conventional capsule medical device generally captures an in-vivo image necessary for observation of a luminal organ such as a small intestine or a large intestine, and thus has a light intensity distribution suitable for illumination of the luminal organ. Illumination light is emitted to illuminate the internal organ, which is the subject, and an in-vivo image is taken. However, such a conventional capsule medical device is similar to the case of imaging a luminal organ even when imaging an in-vivo image facing the inner wall surface of the organ as exemplified by imaging of the stomach or the like. In order to capture an in-vivo image by irradiating illumination light on an inner wall of an organ, which is a subject, there is a possibility of capturing an in-vivo image that has caused halation due to an excessive amount of light at the center of the imaging field of view. In the medical field, there is a demand for a capsule medical device that can capture an in-vivo image with appropriate brightness regardless of the imaging scene inside the subject.

  The present invention has been made in view of the above circumstances, and provides a capsule medical device capable of adjusting the amount of illumination light corresponding to an imaging scene inside a subject and capturing an in-vivo image with appropriate brightness. The purpose is to do.

  In order to solve the above-described problems and achieve the object, a capsule medical device according to the present invention includes one or more illumination units that illuminate a subject by irradiating illumination light inside an organ of the subject, and the illumination light. An image capturing unit that captures an image of the subject illuminated by the image capturing unit, and an image capturing scene of the image based on luminance information of the image captured by the image capturing unit, and the illumination light corresponding to the determined image capturing scene. And a control unit for controlling the amount of light.

  In the capsule medical device according to the present invention, in the above invention, the control unit calculates the luminance information that is each average luminance value of a partial image region obtained by dividing the image into a plurality of regions. The imaging scene of the image is determined based on the luminance information.

  In the capsule medical device according to the present invention, in the above invention, the control unit calculates a luminance comparison value based on each average luminance value of the plurality of partial image regions, and the calculated luminance comparison value When the brightness comparison value is equal to or less than the brightness target value, the amount of the illumination light is increased, and the brightness comparison value is larger than the brightness target value. The amount of illumination light is reduced.

  In the capsule medical device according to the present invention as set forth in the invention described above, the control unit switches the calculation method of the luminance comparison value in accordance with the imaging scene of the image.

  In the capsule medical device according to the present invention, in the above invention, when the control unit is an imaging scene in which a luminance change in the screen of the image is less than a predetermined reference level, the entire image region of the image When the luminance comparison value that is the average luminance value of the image is an imaging scene in which the luminance change in the screen of the image is equal to or higher than the predetermined reference level, each weighting coefficient that differs according to the luminance range and each The luminance comparison value is calculated by averaging each multiplication value with the average luminance value.

  In the capsule medical device according to the present invention as set forth in the invention described above, the control unit switches the light emission pattern of the illumination light in accordance with the imaging scene of the image.

  In the capsule medical device according to the present invention as set forth in the invention described above, the one or more illumination units are plural, and the control unit is included in the plurality of illumination units corresponding to the imaging scene of the image. An illumination unit that emits illumination light of the light emission pattern is selected.

  In the capsule medical device according to the present invention, one or more illumination units illuminate the subject by irradiating illumination light inside the organ of the subject, and the imaging unit captures an image of the subject illuminated by the illumination light. The control unit determines the imaging scene of the image based on the luminance information of the image captured by the imaging unit, and controls the amount of the illumination light corresponding to the determined imaging scene. Even when the imaging scene inside changes, the amount of illumination light can be adjusted according to the imaging scene inside the subject. There is an effect that a capsule medical device capable of capturing an in-vivo image with appropriate brightness can be realized.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a capsule medical device according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a schematic diagram illustrating a configuration example of the in-vivo image acquisition system according to the first embodiment of the present invention. As shown in FIG. 1, the in-vivo image acquisition system according to the first embodiment includes a capsule medical device 2 that captures an in-vivo image of a subject 1, and the body of the subject 1 captured by the capsule medical device 2. A receiving device 3 for receiving an image, an image display device 4 for displaying an in-vivo image of the subject 1, and a portable storage medium 5 for transferring data between the receiving device 3 and the image display device 4 With.

  The capsule medical device 2 is a capsule medical device having an imaging function and a wireless communication function. Specifically, the capsule medical device 2 is introduced into the body of the subject 1 such as a patient by oral ingestion or the like, and then moves inside the digestive tract of the subject 1 by a peristaltic motion or the like, and finally the subject. 1 is discharged to the outside. The capsule medical device 2 adjusts the illumination light amount of the subject 1 for each imaging scene inside the organ during a period from introduction into the subject 1 to discharge to the outside of the subject 1. The in-vivo images are sequentially captured, and the obtained in-vivo images are sequentially wirelessly transmitted to the external receiving device 3.

  The receiving device 3 is for receiving an in-vivo image group of the subject 1 imaged by the capsule medical device 2. Specifically, the receiving device 3 includes a plurality of receiving antennas 3 a to 3 h distributed on the body surface of the subject 1, and is carried by the subject 1. The receiving device 3 receives a radio signal from the capsule medical device 2 inside the subject 1 via the plurality of receiving antennas 3a to 3h, and demodulates the received radio signal into an image signal each time. The receiving device 3 sequentially acquires image data based on such image signals, that is, in-vivo images of the subject 1 captured by the capsule medical device 2. Further, the storage medium 5 is detachably inserted into the receiving device 3. The receiving device 3 accumulates the in-vivo image group of the subject 1 thus acquired in the storage medium 5.

  The receiving antennas 3a to 3h may be distributed at predetermined positions of a jacket worn by the subject 1. In this case, the receiving antennas 3a to 3h are distributed on the body surface of the subject 1 when the subject 1 wears this jacket. In addition, it is sufficient that at least one receiving antenna of the receiving device 3 is arranged on the body surface of the subject 1, and the number of arrangement is not particularly limited to eight.

  The image display device 4 has a configuration like a workstation that displays various information such as an in-vivo image of the subject 1 imaged by the capsule medical device 2. Specifically, the image display device 4 is inserted with the storage medium 5 removed from the receiving device 3 described above, and captures the in-vivo image group and the like of the subject 1 accumulated in the storage medium 5. The image display device 4 displays the in-vivo image group of the subject 1 on the display in response to an operation by a user such as a doctor or a nurse. The user can examine the inside of the organ of the subject 1 by observing the in-vivo image group displayed on the image display device 4.

  The storage medium 5 is a portable storage medium for transferring data between the receiving device 3 and the image display device 4 described above. Specifically, the storage medium 5 is detachable from the receiving device 3 and the image display device 4 and has a structure capable of outputting and recording data when being inserted into both. When the storage medium 5 is inserted into the receiving device 3, the in-vivo image group of the subject 1 received by the receiving device 3 is accumulated. When the storage medium 5 is inserted into the image display device 4, the in-vivo body of the subject 1 is stored. Accumulated data such as an image group is output to the image display device 4.

  Next, the configuration of the capsule medical device 2 according to the first embodiment of the present invention will be described in detail. FIG. 2 is a schematic diagram illustrating a configuration example of the capsule medical device according to the first embodiment of the present invention. FIG. 3 is a schematic view illustrating the capsule medical device viewed from the direction D shown in FIG. As shown in FIGS. 2 and 3, the capsule medical device 2 according to the first embodiment includes a capsule housing 20 having a size that can be introduced into the organ of the subject 1 and a subject inside the subject 1. A plurality of illuminating units 21a to 21d to be illuminated, an image inside the organ illuminated by the illuminating units 21a to 21d, that is, an imaging unit 22 that captures an in-vivo image of the subject 1, and an in-vivo image captured by the imaging unit 22 A transmission unit 23 that wirelessly transmits to the outside, a storage unit 24 that stores information necessary for dimming of the illumination units 21a to 21d, a control unit 25 that controls each component of the capsule medical device 2, a battery, and the like And a power supply unit 26 realized by the above.

  The capsule-type housing 20 is a capsule-type housing formed in a size that can be introduced into the digestive tract of the subject 1, and the other end (opening end) of the cylindrical housing 20a having one end having a dome shape. This is realized by closing the dome with a dome-shaped casing 20b. The dome-shaped housing 20b is a dome-shaped optical member that is transparent to light of a predetermined wavelength band such as visible light. On the other hand, the cylindrical housing 20a is substantially opaque to visible light. Inside the capsule casing 20 formed by the cylindrical casing 20a and the dome-shaped casing 20b are illumination units 21a to 21d, an imaging unit 22, a transmission unit 23, a storage unit 24, a control unit 25, and a power source. The unit 26 is accommodated in a liquid-tight state.

  The illumination units 21 a to 21 d are for illuminating the subject of the imaging unit 22. Specifically, each of the illumination parts 21a-21d is implement | achieved using light emitting elements, such as LED. The illuminating units 21a to 21d emit illumination light having a light amount controlled by the control unit 25, and irradiate the illuminating light inside the organ of the subject 1 through the dome-shaped housing 20b to illuminate the subject of the imaging unit 22. Illuminate.

  The imaging unit 22 captures an image of a subject illuminated by the illumination light emitted by the illumination units 21a to 21d, that is, an in-vivo image of the subject 1. Specifically, the imaging unit 22 includes an optical system 22a such as a condenser lens and a solid-state imaging element 22b such as a CCD or CMOS image sensor. The optical system 22a condenses the reflected light from the subject illuminated by the illumination units 21a to 21d, and forms an optical image of the subject on the light receiving surface of the solid-state imaging device 22b. The solid-state imaging device 22b takes an image of a subject within an imaging field range defined by the imaging direction and the angle of view, for example, with a direction parallel to the longitudinal central axis CL of the capsule housing 20 as an imaging direction. . In this case, the solid-state imaging device 22b captures an optical image of the subject imaged by the optical system 22a, that is, an in-vivo image of the subject 1. Note that the optical axis of the imaging unit 22 is preferably coincident with the central axis CL of the capsule housing 20.

  The transmission unit 23 includes a transmission antenna 23a, and wirelessly transmits the in-vivo image of the subject 1 to the reception device 3 outside the subject 1 (see FIG. 1) using the transmission antenna 23a. Specifically, the transmission unit 23 acquires an image signal including in-vivo image data of the subject 1 imaged by the imaging unit 22, and performs predetermined modulation processing or the like on the acquired image signal each time. Then, a radio signal including the image signal of the subject 1 is generated. The transmission unit 23 sequentially transmits the wireless signal generated in this way to the outside via the transmission antenna 23a. The radio signal (that is, the in-vivo image of the subject 1) transmitted by the transmission unit 23 is received by the reception device 3 via the plurality of reception antennas 3a to 3h described above.

  The memory | storage part 24 memorize | stores various information required for control of the light quantity of the illumination light which the illumination parts 21a-21d mentioned above light-emit. Specifically, the storage unit 24 relates to coefficient information 24a including a filter coefficient used for the determination process of the in-vivo image captured scene, and a weighting coefficient used to control the amount of illumination light corresponding to the captured scene. Weighting information 24b and dimming information 24c including a luminance target value indicating ideal brightness of the in-vivo image are stored. The storage unit 24 operates based on the control of the control unit 25 and transmits information instructed to be read by the control unit 25 to the control unit 25. In addition, the storage unit 24 stores information instructed to be stored by the control unit 25.

Here, the weighting coefficient W _ij based on the weighting information 24b is used to weight the average luminance value Y _ij of the plurality of partial image areas A _ij included in the in-vivo image in the light amount control of the illumination light according to the imaging scene. It is a coefficient to do. Specifically, as shown in FIG. 4, the weighting coefficient W _ij is set to a different value corresponding to the luminance range of the average luminance value Y _ij of the plurality of partial image areas A _ij inside the in-vivo image. That is, when the average luminance value Y _ij is a luminance value within the range of 0 to 255, the weighting coefficient W _ij assigned to the average luminance value Y _ij within the luminance range of 0 to 50 is “0”. The weighting coefficient W _ij assigned to the average luminance value Y _ij within the 100 luminance range is “0.25”. The weighting coefficient W _ij assigned to the average luminance value Y _ij in the luminance range 101 to 150 is “0.5”, and the weighting coefficient W assigned to the average luminance value Y _ij in the luminance range 151 to 200 is set. _ij is “0.75”, and the weighting coefficient W _ij assigned to the average luminance value Y _ij within the luminance range of 201 to 255 is “1”. Such weighting factors W _ij is with increasing average luminance value Y _ij increasing the contribution rate of the average luminance value Y _ij for the light amount control of the illumination light, the light amount control of the illumination light with a decrease in the average luminance value Y _ij The contribution ratio of the average luminance value Y _ij to is reduced.

The partial image area A _ij , the average luminance value Y _ij, and i and j of the weighting coefficient W _ij are all integers of 1 or more, and indicate the address of the partial image area A _{ij in} the in-vivo image. For example, when the partial image area A _ij is an image area formed by dividing an in-vivo image for one frame into a plurality of grids, i indicates the number of rows of the partial image area A _ij , and j is the partial image. The number of columns in the area A _ij is shown.

  The control unit 25 controls each component (the illumination units 21a to 21d, the imaging unit 22, the transmission unit 23, and the storage unit 24) of the capsule medical device 2, and inputs / outputs signals between the component units. Control. Specifically, the control unit 25 performs the light emission operation timings of the illumination units 21a to 21d so that the imaging unit 22 captures images inside the organ illuminated by the illumination light emitted by the illumination units 21a to 21d, that is, in-vivo images. And the imaging operation timing of the imaging unit 22 are controlled.

  In addition, the control unit 25 includes a signal processing unit 25a that generates an image signal of the in-vivo image. The signal processing unit 25a acquires a signal photoelectrically converted by the solid-state imaging element 22b of the imaging unit 22, performs predetermined signal processing on the acquired signal, and includes an in-vivo image data of the subject 1 Generate a signal. The control unit 25 sequentially transmits the image signal generated by the signal processing unit 25a to the transmission unit 23, and controls the transmission unit 23 so that the image signal is sequentially wirelessly transmitted to the outside.

Furthermore, the control unit 25 includes a scene determination unit 25b, a comparison value calculation unit 25c, and a light amount adjustment unit 25d. The scene discriminating unit 25b discriminates the imaging scene of the in-vivo image. Specifically, each time the image capturing unit 22 captures an in-vivo image, the scene determination unit 25b has each average brightness value that is brightness information of a plurality of partial image areas A _ij included in the captured in-vivo image for one frame. Based on Y _ij , the imaging scene of this in-vivo image is determined. In this case, the scene determination unit 25b calculates a scene determination value for each assumed shooting scene using the filter coefficient for each assumed shooting scene and the average luminance value _Yij included in the coefficient information 24a in the storage unit 24. The scene discriminating unit 25b performs the scene discrimination value comparison process, and discriminates the imaging scene of the in-vivo image based on the result of the comparison process.

The comparison value calculation unit 25c calculates a luminance comparison value for controlling the amount of illumination light of the illumination units 21a to 21d corresponding to the imaging scene of the in-vivo image. Specifically, the comparison value calculation unit 25c is preset with a different luminance comparison value calculation method for each assumed imaging scene, and the luminance comparison value calculation method corresponding to the imaging scene determined by the scene determination unit 25b. Switch. The comparison value calculation unit 25c calculates a luminance comparison value based on the calculation method selected corresponding to the imaging scene. More specifically, when the in-vivo image capturing scene is a lumen, the comparison value calculation unit 25c calculates an average luminance value of all image regions of the in-vivo image for one frame as a luminance comparison value. On the other hand, when the in-vivo image capturing scene is a wall surface portion, the comparison value calculating unit 25c weights the average luminance value Y _{ij of the} plurality of partial image areas A _ij included in the in-vivo image for one frame and the storage unit 24. A luminance comparison value corresponding to the in-vivo image is calculated using the weighting coefficient W _ij based on the information 24b.

  Note that a luminal part, which is an example of an in-vivo image capturing scene, is an imaging scene when capturing an inside of a luminal organ such as a small intestine or a large intestine inside the subject 1. For example, solid imaging in the imaging unit 22 is performed. In this imaging scene, the distance between the light receiving surface of the element 22b and the subject increases from the periphery of the imaging field of view toward the center. That is, the luminance change in the screen of the in-vivo image captured when the imaging scene is a lumen is less than a predetermined reference level. On the other hand, a wall surface portion, which is an example of an in-vivo image capturing scene, captures an in-vivo image facing an inner wall surface of an organ in which the diameter of an internal space such as the stomach inside the subject 1 is larger than that of a luminal organ. For example, an imaging scene in which the distance between the light receiving surface of the solid-state imaging element 22b in the imaging unit 22 and the subject hardly changes between the periphery and the center of the imaging visual field range. That is, the luminance change in the screen of the in-vivo image captured when the imaging scene is the wall surface portion is equal to or higher than the predetermined reference level.

  The light amount adjustment unit 25d adjusts the light amount of the illumination light of the illumination units 21a to 21d corresponding to the imaging scene of the in-vivo image. Specifically, the light amount adjustment unit 25d reads a preset luminance target value from the dimming information 24c in the storage unit 24, and the acquired luminance target value and the above-described comparison value calculation unit 25c calculate. The luminance comparison value is compared. The light amount adjustment unit 25d calculates the amount of illumination light to be emitted by the illumination units 21a to 21d based on the result of the comparison process between the luminance target value and the luminance comparison value. The light amount adjustment unit 25d adjusts the light emission amounts of the illumination units 21a to 21d so that the calculated light amount matches the actual light amount of the illumination light. The control unit 25 controls the illumination units 21a to 21d so as to emit illumination light with the light emission amount adjusted by the light amount adjustment unit 25d. In this case, the control unit 25 controls the light emission amount (that is, the amount of illumination light) of the illumination units 21a to 21d by controlling the light emission time or the energization amount (current value) of the illumination units 21a to 21d.

  The power supply unit 26 is realized using a switch circuit, a battery, and the like. The power supply unit 26 supplies power to each component of the capsule medical device 2 when switched on by the switch circuit, and stops power supply to these components when switched to the off state. The switch circuit (not shown) of the power supply unit 26 may be a magnetic switch that switches an on / off state by an external magnetic field applied from outside, or predetermined light (for example, infrared light or the like) incident from the outside. ) May be an optical switch that switches between on and off states.

  Next, the filter coefficient in the coefficient information 24a used for the discrimination processing of the imaging scene of the in-vivo image will be described by exemplifying a case where a lumen part and a wall surface part are assumed as the imaging scene of the in-vivo image. FIG. 5 is a schematic view illustrating the light intensity distribution of illumination light emitted from the illumination unit of the capsule medical device. FIG. 6 is a schematic diagram for explaining filter coefficients when a lumen is assumed as an imaging scene. FIG. 7 is a schematic diagram for explaining filter coefficients when a wall surface is assumed as an imaging scene.

  The illuminating units 21a to 21d of the capsule medical device 2 illustrated in FIGS. 2 and 3, when the imaging unit 22 captures an in-vivo image of the subject 1, as described above, the subject that is the subject of the imaging unit 22 The inside of one organ is illuminated with illumination light. The illumination light emitted by the illumination units 21a to 21d has a light intensity distribution as exemplified by the curve L1 in FIG. That is, the light intensity of the illumination light of the illumination units 21a to 21d has a maximum value at the center of the imaging field of the imaging unit 22, and decreases in a quadratic function from the center of the imaging field toward the periphery. . When the central axis CL of the capsule medical device 2 and the optical axis of the imaging unit 22 coincide with each other, the center of the imaging field of the imaging unit 22 is located at a position on the central axis CL of the capsule medical device 2. Become.

  Here, when the imaging scene of the in-vivo image is a lumen part, the illumination units 21a to 21d irradiate the tubular subject with illumination light having a light intensity distribution exemplified by the curve L1. The imaging unit 22 receives reflected light from the tubular subject illuminated by the illumination light, and captures an image (in-vivo image) of the tubular subject. In this case, the reflected light from the tubular subject incident on the light receiving surface of the solid-state imaging device 22b has a light intensity distribution as exemplified by the curve L2 in FIG. That is, the light receiving intensity (hereinafter referred to as plate surface illuminance) of the reflected light on the light receiving surface of the solid-state imaging device 22b is substantially constant in the region from the center of the light receiving surface to the vicinity of the edge, and from the vicinity of the edge. It gradually increases toward the outer periphery of the light receiving surface.

The filter coefficient K1 _ij when such a lumen is assumed to be an in-vivo image capturing scene has a reciprocal relationship with the plate surface illuminance due to the reflected light from the lumen-like subject. That is, as shown in FIG. 6, the filter coefficient K1 _ij has a value on the curve L4 having a reciprocal relationship with the curve L2 indicating the light intensity distribution of the plate surface illuminance corresponding to the lumen. The filter coefficient K1 _ij is set in advance as a filter coefficient corresponding to a lumen portion assumed as an in-vivo image capturing scene. The storage unit 24 described above stores the filter coefficient K1 _ij as part of the coefficient information 24a.

  On the other hand, when the imaging scene of the in-vivo image is a wall surface portion, the illumination units 21a to 21d irradiate the organ wall surface subject with illumination light having a light intensity distribution exemplified by the curve L1 illustrated in FIG. The imaging unit 22 receives reflected light from an organ wall-shaped subject illuminated by the illumination light, and captures an image (in-vivo image) of the organ wall-shaped subject. In this case, the reflected light from the organ wall-shaped subject incident on the light receiving surface of the solid-state imaging device 22b has a light intensity distribution as exemplified by the curve L3 in FIG. That is, the plate surface illuminance on the light receiving surface of the solid-state imaging element 22b becomes a maximum value at the center of the light receiving surface and decreases in a quadratic function from the center of the light receiving surface toward the outer periphery.

Such a filter coefficient K2 _ij when the wall portion is assumed to the image scene of the in-vivo image is a relation of the plate surface illuminance and reciprocal by the reflected light from such organs wall-like object. That is, as shown in FIG. 7, the filter coefficient K2 _ij has a value on a curve L5 having a reciprocal relationship with the curve L3 indicating the light intensity distribution of the plate surface illuminance corresponding to the wall surface. The filter coefficient K2 _ij is set in advance as a filter coefficient corresponding to a wall surface portion assumed as an in-vivo image capturing scene. The storage unit 24 described above stores the filter coefficient K2 _ij as part of the coefficient information 24a.

  Next, the operation of the capsule medical device 2 when controlling the amount of illumination light corresponding to the imaging scene of the in-vivo image will be described. FIG. 8 is a flowchart illustrating the processing procedure of the control unit of the capsule medical apparatus according to the first embodiment of the present invention. The control unit 25 of the capsule medical device 2 performs the processing procedure shown in FIG. 8 to determine the imaging scene of the in-vivo image, and controls the amount of illumination light corresponding to the determined imaging scene.

  That is, as shown in FIG. 8, the control unit 25 first controls the illumination units 21 a to 21 d so as to illuminate the subject of the imaging unit 22 by irradiating illumination light inside the organ of the subject 1, and The imaging unit 22 is controlled to capture an image of the subject illuminated by the illumination light, that is, an in-vivo image of the subject 1 (step S101). In step S101, the control unit 25 controls the illumination units 21a to 21d so as to emit the illumination light with the light amount adjusted by the light amount adjustment unit 25d. The control unit 25 acquires in-vivo image data for one frame based on a signal photoelectrically converted by the solid-state imaging element 22b. The control unit 25 controls the transmission unit 23 to transmit an image signal including the in-vivo image data to the transmission unit 23 and wirelessly transmit the image signal to the external reception device 3 (see FIG. 1). To do.

Next, the control unit 25 calculates an average luminance value of each partial image region in the in-vivo image for one frame acquired in step S101 (step S102). In step S102, the control unit 25 sets a plurality of partial image areas A _ij inside the in-vivo image for one frame acquired from the imaging unit 22, and each average luminance value Y of the plurality of partial image areas A _ij is obtained. Each _ij is calculated.

Subsequently, the control unit 25 performs an in-vivo image capturing scene determination process based on each average luminance value Y _ij calculated in step S102 (step S103). Thereafter, when the imaging scene determined in step S103 is a luminal part (step S104, luminal), the control unit 25 calculates a luminance comparison value assuming the luminal part as the in-vivo image imaging scene (step S104). S105). In step S105, the comparison value calculation unit 25c performs a calculation process for averaging the luminance values of the in-vivo image for one frame acquired in step S101 over the entire image region. The average luminance value is calculated as a luminance comparison value.

On the other hand, when the imaging scene determined in step S103 is a wall surface (step S104, wall surface), the control unit 25 calculates a luminance comparison value assuming the wall surface as the in-vivo image capturing scene (step S106). Each In step S106, the comparison value calculation section 25c reads out the weighting information 24b from the storage unit 24, based on the weighting information 24b, the weighting coefficient W _ij for each average luminance value Y _ij for each partial image region A _ij calculate. In this case, the comparison value calculation unit 25c, each based on the correspondence between the luminance range and the weighting factor of the average luminance values as illustrated in FIG. 4, allocates each average luminance value Y _ij for each partial image region A _ij A weighting coefficient W _ij is calculated. The comparison value calculation unit 25c calculates each multiplication value E _ij (E _ij = Y _ij × W _ij ) obtained by multiplying each average luminance value Y _ij and each weighting coefficient W _ij , and each calculated multiplication value. The integrated value of E _ij is divided by the quantity (= i × j) of the partial image area A _ij , thereby calculating a luminance comparison value.

  As described above, the control unit 25 switches the luminance comparison value calculation method to either the calculation method of step S105 or the calculation method of step S106 corresponding to the imaging scene determined in step S103, and the luminance is determined by the selected calculation method. A comparison value is calculated.

  Next, the control unit 25 determines whether or not the brightness comparison value calculated as described above is equal to or less than the brightness target value. When the brightness comparison value is equal to or less than the brightness target value (step S107, Yes), the control unit 25 controls the light emission amounts of the illumination units 21a to 21d so as to increase the amount of illumination light (step S108). When the luminance comparison value exceeds the luminance target value (No at Step S107), the light emission amounts of the illumination units 21a to 21d are controlled so as to reduce the amount of illumination light (Step S109). Thereafter, the control unit 25 returns to step S101 described above, and repeats the processing procedure after step S101.

  In steps S107 to S109, the light amount adjustment unit 25d reads a preset luminance target value from the dimming information 24c in the storage unit 24. The light amount adjustment unit 25d compares the luminance target value with the luminance comparison value calculated in step S105 or step S106, and based on the difference between the luminance target value and the luminance comparison value, the illumination units 21a to 21d. Adjusts the amount of illumination light to be emitted. Specifically, the light amount adjustment unit 25d increases the light amount of the illumination light to a light amount that is greater than or equal to the current amount when the luminance comparison value is less than or equal to the luminance target value, and the illumination light when the luminance comparison value exceeds the luminance target value. The amount of light is reduced to a smaller amount than the current state. As a result, the average luminance value of the in-vivo image captured by the imaging unit 22 next time approaches this luminance target value.

  Next, the imaging scene determination process in step S103 described above will be described in detail. FIG. 9 is a flowchart illustrating the processing procedure until the imaging scene determination processing in step S103 shown in FIG. 8 is achieved.

  In the capsule medical device 2 when executing the imaging scene determination process in step S103 described above, as shown in FIG. 9, the control unit 25 first calculates a scene determination value for determining the imaging scene of the in-vivo image. (Step S201).

In step S201, the scene determination unit 25b calculates a scene determination value for each assumed imaging scene. Specifically, the scene discrimination unit 25b, from among the coefficient information 24a in the storage unit 24, and the filter coefficients K1 _ij of assuming the lumen as the imaging scene, assuming the wall portion as the image scene Each filter coefficient _K2ij is read out. The scene discriminating unit 25b multiplies each filter coefficient K1 _ij assumed for the lumen part by each average luminance value Y _ij in the above-described step S102, and each multiplied value H1 _ij (H1 _ij = K1 _ij × Y _ij ). calculate. The scene discriminating unit 25b extracts the maximum value MAX (H1 _ij ) and the minimum value MIN (H1 _ij ) from the multiplication values H1 _ij calculated in this way, and the extracted maximum value MAX (H1 _ij ) and A ratio (= MAX (H1 _ij ) / MIN (H1 _ij )) with the minimum value MIN (H1 _ij ) is calculated as a scene discrimination value B1 assumed for the lumen. In addition, the scene determination unit 25b multiplies each filter coefficient K2 _ij assumed for the wall surface part by each average luminance value Y _ij in step S102 described above, and each multiplication value H2 _ij (H2 _ij = K2 _ij × Y _ij ). Is calculated. Scene discrimination unit 25b, thus the maximum value MAX from among the multiplied values H2 _ij calculated (H2 _ij) and the minimum value MIN (H2 _ij) extracts the, and the extracted maximum value MAX (H2 _ij) The ratio (= MAX (H2 _ij ) / MIN (H2 _ij )) with the minimum value MIN (H2 _ij ) is calculated as the scene determination value B2 assuming the wall surface portion.

  Next, the control unit 25 performs a comparison process between the scene discrimination value B1 assuming the lumen portion and the scene discrimination value B2 assuming the wall surface portion (step S202). In this case, the scene discriminating unit 25b performs a comparison process of the scene discriminating value B1 assumed in the lumen and the scene discriminating value B2 assumed in the wall surface calculated in step S201, and thereby the scene discriminating values B1 and B2 are compared. Understand the size relationship.

  As a result of the comparison processing of the scene determination values B1 and B2, the control unit 25 determines that the lumen-assumed scene determination value B1 is larger than the wall-surface assumed scene determination value B2 (Yes in step S203). It is determined that the imaging scene of the image is a wall surface (step S204), and the process returns to step S103 shown in FIG. On the other hand, when the scene discriminating value B1 assumed for the lumen portion is smaller than the scene discriminating value B2 assumed for the wall surface portion (No in step S203), the control unit 25 determines that the in-vivo image capturing scene is the lumen portion. It discriminate | determines (step S205) and returns to step S103 shown in FIG.

Here, each filter coefficient K1 _ij assumed for the above-described lumen portion has a reciprocal of the plate surface illuminance of the solid-state imaging device 22b by the reflected light from the tubular subject, as exemplified by the curve L4 in FIG. There is a relationship. Therefore, each multiplication value H1 _{ij obtained} by multiplying each filter coefficient K1 _ij assumed for the lumen portion and each average luminance value Y _ij is “1” when the imaging scene of the in-vivo image is a lumen portion. Or it becomes an approximate value of “1”. On the other hand, when the imaging scene of the in-vivo image is a wall surface portion, the difference between the maximum value MAX (H1 _ij ) and the minimum value MIN (H1 _ij ) of each multiplication value H1 _ij is that the imaging scene is a lumen portion. It becomes remarkably larger than the case. Accordingly, the scene discrimination value B1, which is the ratio of the maximum value MAX (H1 _ij ) to the minimum value MIN (H1 _ij ), is “1” or “1” when the imaging scene of the in-vivo image is a lumen. In the case where the imaging scene of the in-vivo image is a wall surface portion, it is significantly larger than “1”.

On the other hand, each filter coefficient K2 _ij assumed for the wall surface portion described above has a reciprocal relationship with the plate surface illuminance of the solid-state imaging device 22b due to the reflected light from the organ wall surface subject, as exemplified by the curve L5 in FIG. is there. Therefore, each multiplication value H2 _{ij obtained} by multiplying each filter coefficient K2 _ij assumed for the wall surface portion and each average luminance value Y _ij is “1” or “ 1 ". On the other hand, when the imaging scene of the in-vivo image is a luminal part, the difference between the maximum value MAX (H2 _ij ) and the minimum value MIN (H2 _ij ) of each multiplication value H2 _ij is that the imaging scene is a wall surface part. It becomes remarkably larger than the case. Therefore, the scene discrimination value B2, which is the ratio of the maximum value MAX (H2 _ij ) to the minimum value MIN (H2 _ij ), is “1” or “1” when the imaging scene of the in-vivo image is a wall surface portion. When it is an approximate value and the imaging scene of the in-vivo image is a luminal part, it is significantly larger than “1”.

  Therefore, the magnitude relationship between the scene discrimination values B1 and B2 corresponds to the in-vivo image capturing scene. Specifically, when the imaging scene of the in-vivo image is a lumen part, the scene determination value B1 assumed for the lumen part is smaller than the scene determination value B2 assumed for the wall part. On the other hand, when the imaging scene of the in-vivo image is a wall surface portion, the scene determination value B1 assumed for the lumen portion is larger than the scene determination value B2 assumed for the wall surface portion.

Next, a capsule medical that controls the amount of illumination light corresponding to the imaging scene of the in-vivo image, exemplifying the case where the plurality of partial image areas A _ij described above are obtained by dividing the in-vivo image into 25 grids. The operation of the device 2 will be specifically described. FIG. 10 is a schematic view illustrating a state in which the capsule medical device captures an in-vivo image inside a luminal organ. FIG. 11 is a schematic diagram illustrating a specific example of the filter coefficient assumed for the lumen portion and the filter coefficient assumed for the wall surface portion. FIG. 12 is a schematic view illustrating a state in which the capsule medical device captures an in-vivo image facing the inner wall surface of the organ. Hereinafter, with reference to FIG. 2 and FIGS. 10 to 12 described above, the operation of the capsule medical device 2 when performing in-vivo image capturing scene determination processing and light amount control of illumination light will be specifically described.

When the capsule medical device 2 reaches the inside of the luminal organ 15 such as the small intestine as shown in FIG. 10, the imaging unit 22 includes the inside of the luminal organ 15 illuminated by the illumination light of the illumination units 21 a to 21 d. An in-vivo image P is captured. In this case, the control unit 25 acquires the data of the in-vivo image P of the luminal organ 15 from the imaging unit 22, and divides the acquired in-vivo image P into a grid of 5 rows × 5 columns to obtain 25 divided partial images. Regions A _{11 to} A ₅₅ are set. Subsequently, the control unit 25, respectively calculate each average luminance value Y ₁₁ to Y ₅₅ of such partial image region A ₁₁ to A _55. From the coefficient information 24a in the storage unit 24, the control unit 25 uses the filter coefficients K1 _{11 to} K1 ₅₅ assumed for the lumen as illustrated in FIG. 11 and the filter coefficients K2 _{11 to} K2 assumed for the wall surface. reads the ₅₅ performs imaging scene discrimination processing of the in-vivo image P with each such average luminance value Y ₁₁ to Y ₅₅ and the filter coefficients _{K1 11 ~K1 55, K2 11 ~K2} 55.

In the imaging scene discrimination processing of the in-vivo image P, the scene discrimination unit 25b multiplies respectively each average luminance value Y ₁₁ to Y ₅₅ of each filter coefficient K1 ₁₁ ~K1 _55-vivo image P of the lumen assumed, Multiplication values H1 _{11 to} H1 ₅₅ (H1 ₁₁ = K1 ₁₁ × Y ₁₁ , H1 ₁₂ = K1 ₁₂ × Y ₁₂ ,..., H1 ₅₄ = K1 ₅₄ × Y ₅₄ , H1 ₅₅ = K1 ₅₅ × Y ₅₅ ) are calculated. . The scene discriminating unit 25b extracts the maximum value MAX (H1 _ij ) and the minimum value MIN (H1 _ij ) from the multiplication values H1 _{11 to} H1 ₅₅ calculated in this way, and this extracted maximum value MAX (H1 The ratio (= MAX (H1 _ij ) / MIN (H1 _ij )) between the _ij ) and the minimum value MIN (H1 _ij ) is calculated as the assumed scene discrimination value B1.

Further, the scene determination unit 25b multiplies respectively each average luminance value Y ₁₁ to Y ₅₅ of each filter coefficient K2 ₁₁ ~K2 _55-vivo image P of the wall portion assumed, each multiplier value H2 ₁₁ ~H2 ₅₅ (H2 ₁₁ = K2 ₁₁ × Y ₁₁ , H2 ₁₂ = K2 ₁₂ × Y ₁₂ ,..., H2 ₅₄ = K2 ₅₄ × Y ₅₄ , H2 ₅₅ = K2 ₅₅ × Y ₅₅ ). Scene discrimination unit 25b, thus the maximum value MAX from among the multiplied values H2 ₁₁ ~H2 ₅₅ calculated (H2 _ij) and the minimum value MIN (H2 _ij) extracts the maximum value MAX (H2 this the extracted The ratio (= MAX (H2 _ij ) / MIN (H2 _ij )) between the _ij ) and the minimum value MIN (H2 _ij ) is calculated as the scene discrimination value B2 assuming the wall surface portion.

  Here, the actual imaging scene of the in-vivo image P is a lumen as shown in FIG. In this case, the scene discriminating value B1 assumed for the lumen portion is “1” or an approximate value of “1”, and the scene discriminating value B2 assumed for the wall surface portion is significantly larger than “1”. The scene discriminating unit 25b compares the scene discriminating values B1 and B2, and grasps that the scene discriminating value B1 assumed for the lumen portion is smaller than the scene discriminating value B2 assumed for the wall surface portion. The scene determination unit 25b determines that the imaging scene of the in-vivo image P is a luminal part based on the result of the comparison processing of the scene determination values B1 and B2.

In this way, when it is determined that the imaging scene of the in-vivo image P is a lumen part, the control unit 25 calculates a luminance comparison value assumed for the lumen part based on the luminance information of the in-vivo image P. In this case, the comparison value calculation unit 25c performs a calculation process that averages the luminance value of the in-vivo image P over the entire image area, and calculates the luminance comparison value assumed for the lumen. Specifically, the comparison value calculation unit 25c integrates the average luminance value Y ₁₁ to Y ₅₅ of the partial image region A ₁₁ to A ₅₅ in the in-vivo image P, the partial image region A ₁₁ an integrated value obtained by this calculation region number of ~A ₅₅ (= 25) by dividing by calculating the average luminance value or the luminance comparison value lumen assumptions whole vivo image P.

  Thereafter, the light amount adjustment unit 25d reads the luminance target value from the dimming information 24c in the storage unit 24, and compares the calculated luminance comparison value assumed in the lumen and the luminance target value. The light amount adjustment unit 25d adjusts the light amount of the illumination light that should be emitted by the illumination units 21a to 21d based on the difference between the luminance target value and the luminance comparison value assumed for the lumen. The control unit 25 controls the illumination units 21a to 21d so as to emit the illumination light with the light amount adjusted by the light amount adjustment unit 25d, thereby controlling the light amount of the illumination light according to the lumen part that is the imaging scene. To achieve.

On the other hand, when the capsule medical device 2 reaches the inside of an organ having a relatively large internal space such as the stomach, the imaging unit 22 illuminates the organ illuminated by the illumination light of the illumination units 21a to 21d as shown in FIG. An internal in-vivo image P is captured in a manner facing the internal organ wall 16. In this case, the control unit 25 acquires the data of the in-vivo image P of the organ inner wall surface 16 from the imaging unit 22, divides the acquired in-vivo image P into a 5 rows × 5 columns grid, and divides it into 25 partial images. Regions A _{11 to} A ₅₅ are set. Subsequently, the control unit 25, respectively calculate each average luminance value Y ₁₁ to Y ₅₅ of such partial image region A ₁₁ to A _55. From the coefficient information 24a in the storage unit 24, the control unit 25 uses the filter coefficients K1 _{11 to} K1 ₅₅ assumed for the lumen as illustrated in FIG. 11 and the filter coefficients K2 _{11 to} K2 assumed for the wall surface. reads the ₅₅ performs imaging scene discrimination processing of the in-vivo image P with each such average luminance value Y ₁₁ to Y ₅₅ and the filter coefficients _{K1 11 ~K1 55, K2 11 ~K2} 55.

In the imaging scene discrimination process of the in-vivo image P, the scene discrimination unit 25b, as in the case of the luminal organ 15, described above, each filter coefficient K1 _{11 to} K1 ₅₅ assumed for the luminal portion and each average luminance of the in-vivo image P. calculates the value Y ₁₁ each multiplication value obtained by multiplying each of the ~Y ₅₅ H1 ₁₁ ~H1 _55, the maximum value MAX of each such multiplication value H1 ₁₁ ~H1 ₅₅ (H1 _ij) and the minimum value MIN (H1 _ij) The ratio (= MAX (H1 _ij ) / MIN (H1 _ij )) is calculated as the assumed scene discrimination value B1 of the lumen. Further, the scene determination unit 25b calculates the respective multiplied values H2 ₁₁ ~H2 ₅₅ multiplied respectively and each mean luminance values Y ₁₁ to Y ₅₅ of each filter coefficient K2 ₁₁ ~K2 _55-vivo image P of the wall portion supposed Then, the scene discrimination based on the assumption of the wall surface portion is the ratio (= MAX (H2 _ij ) / MIN (H2 _ij )) between the maximum value MAX (H2 _ij ) and the minimum value MIN (H2 _ij ) of the multiplication values H2 _{11 to} H2 _55. Calculated as value B2.

  Here, the actual imaging scene of the in-vivo image P is a wall surface portion as shown in FIG. In this case, the scene determination value B2 assumed for the wall surface portion is “1” or an approximate value of “1”, and the scene determination value B1 assumed for the lumen portion is significantly larger than “1”. The scene discriminating unit 25b compares the scene discriminating values B1 and B2, and grasps that the scene discriminating value B1 assumed for the lumen portion is larger than the scene discriminating value B2 assumed for the wall surface portion. The scene determination unit 25b determines that the imaging scene of the in-vivo image P is a wall surface based on the result of the comparison processing of the scene determination values B1 and B2.

As described above, when it is determined that the imaging scene of the in-vivo image P is the wall surface portion, the control unit 25 calculates the assumed wall surface portion luminance comparison value based on the luminance information of the in-vivo image P. In this case, the comparison value calculation unit 25c, based on the weighting information 24b in the storage unit 24, calculates a weighting coefficient W ₁₁ to _W-55 to assign each respective average luminance values Y ₁₁ to Y ₅₅ of the in-vivo image P. Comparison value calculating unit 25c multiplies each with respective average luminance values Y ₁₁ to Y ₅₅ of the in-vivo image P a respective weighting factors W ₁₁ to _W-55, the multiplication value _{E 11 ~E 55 (E 11 =} W 11 _{× Y 11, E 12 = W} 12 × Y 12, ..., and calculates the _{E 54 = W 54 × Y 54} , E 55 = W 55 × Y 55). Comparison value calculating unit 25c integrates each such multiplication value E ₁₁ to E _55, the cumulative value thus calculated by dividing the partial image region A ₁₁ number of regions ~A ₅₅ (= 25), the wall portion supposed A luminance comparison value is calculated.

  Thereafter, the light amount adjustment unit 25d reads the luminance target value from the dimming information 24c in the storage unit 24, and compares the calculated luminance comparison value of the wall surface portion with the luminance target value. The light amount adjustment unit 25d adjusts the light amount of the illumination light to be emitted by the illumination units 21a to 21d based on the difference between the luminance target value and the luminance comparison value assumed for the wall surface. The control unit 25 controls the illumination units 21a to 21d so as to emit the illumination light with the light amount adjusted by the light amount adjustment unit 25d, thereby controlling the light amount of the illumination light according to the wall surface part that is the imaging scene. Achieve.

  As described above, in the first embodiment of the present invention, the imaging unit captures an image of the subject illuminated by the illumination light irradiated by the illumination unit inside the organ of the subject, that is, an in-vivo image. Luminance information such as each average luminance value of a plurality of partial image areas included in the in-vivo image is calculated, and based on the calculated luminance information, the imaging scene of the in-vivo image is determined, and the determined imaging scene is supported. Thus, the light amount of the illumination light is controlled. For this reason, even when the imaging scene inside the subject changes to a lumen part or a wall surface part, the amount of illumination light can be adjusted corresponding to the imaging scene inside the subject. A capsule medical device capable of capturing an in-vivo image with appropriate brightness while suppressing the occurrence of halation by irradiating an appropriate amount of illumination light inside the organ can be realized.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. In the first embodiment described above, the amount of illumination light is controlled corresponding to the identified imaging scene. In the second embodiment, the amount of illumination light and the light emission pattern are associated with the identified imaging scene. To control.

  FIG. 13 is a schematic diagram illustrating a configuration example of a capsule medical apparatus according to the second embodiment of the present invention. FIG. 14 is a schematic view illustrating the capsule medical device viewed from the direction D shown in FIG. As shown in FIGS. 13 and 14, the capsule medical device 31 according to the second embodiment includes a control unit 35 instead of the control unit 25 of the capsule medical device 2 according to the first embodiment described above. It further includes a plurality of illumination units 32a to 32d that emit illumination light having higher directivity than the units 21a to 21d. In the capsule medical device 31, the storage unit 24 stores coefficient information 34a instead of the coefficient information 24a described above. The in-vivo image acquisition system according to the second embodiment includes a capsule medical device 31 instead of the capsule medical device 2 of the in-vivo image acquisition system according to the first embodiment (see FIG. 1). Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same components.

  The illumination parts 32a-32d are illumination light sources with strong directivity compared with the illumination parts 21a-21d mentioned above. Specifically, the illumination units 32a to 32d are realized by using light emitting elements such as LEDs, and as shown in FIG. 14, the substrate surface between the illumination units 21a to 21d and the imaging unit 22, that is, the illumination unit 21a. It is arranged closer to the imaging unit 22 (inner side) than ˜21d. The illuminating units 32a to 32d emit illumination light having a light amount controlled by the control unit 35, and irradiate the illuminating light into the organ of the subject 1 through the dome-shaped housing 20b to illuminate the subject of the imaging unit 22. Illuminate. In this case, the illumination light from the illumination units 32a to 32d is concentrated on the center side of the imaging field range of the imaging unit 22 as compared with the illumination light of the outside illumination units 21a to 21d.

  The control unit 35 has an imaging scene discrimination processing function in accordance with an illumination light emission pattern (hereinafter sometimes referred to as an illumination pattern) when an in-vivo image is captured, and the illumination light quantity and the illumination light in accordance with the identified imaging scene. And a lighting pattern control function. Specifically, the control unit 35 includes a scene determination unit 35b instead of the scene determination unit 25b in the first embodiment described above, and further includes an illumination selection unit 35e for illumination pattern control.

The scene discriminating unit 35b discriminates an imaging scene according to an illumination pattern when an in-vivo image is captured. Specifically, each time the imaging unit 22 captures an in-vivo image, the scene determination unit 35b determines an illumination pattern at the time of capturing the in-vivo image, and a plurality of partial image regions included in the in-vivo image for one frame. Based on each average luminance value Y _ij which is the luminance information of A _ij and the illumination pattern at the time of imaging, the imaging scene of this in-vivo image is determined. In this case, the scene determination unit 35b uses the filter coefficient and the average luminance value Y _ij for each illumination pattern and each assumed imaging scene included in the coefficient information 34a in the storage unit 24, for each illumination pattern at the time of in-vivo image capturing. A scene discrimination value is calculated for each assumed imaging scene. The scene discriminating unit 35b performs the scene discrimination value comparison process, and discriminates the imaging scene of the in-vivo image based on the result of the comparison process. Note that the control unit 35 divides the in-vivo image into, for example, a grid and sets a plurality of partial image areas A _ij as in the first embodiment described above.

  The illumination selection unit 35e selects an illumination unit that is a light emission operation target corresponding to the imaging scene of the in-vivo image. Specifically, the illumination selection unit 35e receives illumination light from the outer illumination units 21a to 21d and the inner illumination units 32a to 32d described above corresponding to the captured scene determined by the scene determination unit 35b. Select the illumination unit to emit light. For example, the illumination selection unit 35e is one of the outer illumination units 21a to 21d, the inner illumination units 32a to 32d, and all the illumination units 21a to 21d and 32a to 32d corresponding to the determined imaging scene. Select the lighting unit group. The control unit 35 controls the illumination units 21a to 21d and 32a to 32d so that the illumination unit group selected by the illumination selection unit 35e emits the illumination light having the light amount by the light amount adjustment unit 25d. Thereby, the control unit 35 controls the illumination pattern according to the imaging scene of the in-vivo image.

  The control unit 35 includes the control unit 25 of the capsule medical device 2 according to the first embodiment other than the imaging scene determination processing function according to the illumination pattern and the illumination pattern control function according to the imaging scene as described above. It has the same function.

  In the second embodiment, the light amount adjustment unit 25d adjusts the light amount of the illumination unit group selected by the illumination selection unit 35e in the same manner as in the first embodiment. The control unit 35 controls the illumination units 21a to 21d and 32a to 32d so as to emit the illumination light with the light amount adjusted by the light amount adjustment unit 25d. In this case, the control unit 35 controls the light emission time or the energization amount (current value) of the illumination units 21a to 21d and 32a to 32d, thereby causing the light emission amounts of the illumination units 21a to 21d and 32a to 32d (that is, the illumination light). Light intensity).

On the other hand, the coefficient information 34a in the storage unit 24 includes a plurality of types of filter coefficients that are different for each imaging scene assumed for the above-described lumen part and wall surface part and for each illumination pattern at the time of in-vivo image capturing. Specifically, assuming two imaging scenes of the in-vivo image, a lumen part and a wall surface part, as an illumination pattern, a normal pattern by the outer illumination parts 21a to 21d, a central concentration pattern by the inner illumination parts 32a to 32d, and Assuming three combined patterns of all the illumination units 21a to 21d and 32a to 32d, the storage unit 24 uses six types of filter coefficients K1 _{ij to} K6 _ij that are different for each imaging scene and for each illumination pattern as coefficient information 34a. Remember.

Of the six types of filter coefficients K1 _{ij to} K6 _ij , the filter coefficients K1 _ij , K3 _ij , K5 _ij are filter coefficients assumed for the lumen, and the filter coefficients K2 _ij , K4 _ij , K6 _ij are wall surfaces. This is an assumed filter coefficient. The filter coefficients K1 _ij and K2 _ij are filter coefficients corresponding to the illumination patterns (normal patterns) by the outer illumination units 21a to 21d, and the filter coefficients K3 _ij and K4 _ij are derived from the inner illumination units 32a to 32d. This is a filter coefficient corresponding to a centrally-concentrated illumination pattern (center-concentrated pattern), and the filter coefficients K5 _ij and K6 _ij are combined into a combined illumination pattern (synthetic pattern) by all the illumination units 21a to 21d and 32a to 32d. Corresponding filter coefficients.

  Next, an illumination pattern of the capsule medical device 31 according to the second embodiment will be described. FIG. 15 is a schematic view illustrating a centralized illumination pattern by the inner illumination unit. FIG. 16 is a schematic view illustrating a combined illumination pattern by all illumination units.

  The inner illumination parts 32a to 32d shown in FIGS. 13 and 14 are illumination light sources having higher directivity than the outer illumination parts 21a to 21d as described above, and the inner illumination parts 32a to 32d emit light. The illumination light to have has a light intensity distribution as exemplified by the curve L11 in FIG. That is, the light intensity of the illumination light of the inner illumination units 32a to 32d is narrower than the light intensity distribution (see FIG. 5) of the illumination light of the illumination units 21a to 21d described above, and the imaging unit 22 It becomes a maximum value at the center of the imaging field of view and decreases in a quadratic function from the center of the imaging field of view toward the periphery. When the central axis CL of the capsule medical device 31 and the optical axis of the imaging unit 22 coincide with each other, the center of the imaging field of the imaging unit 22 is located at a position on the central axis CL of the capsule medical device 31. Become.

  The illumination light having a light intensity distribution as exemplified by the curve L11 in FIG. 15 has a narrower illumination width than the illumination lights of the outer illumination units 21a to 21d, but is near the center of the imaging field of the imaging unit 22 The light intensity is stronger than the illumination light of the outer illumination units 21a to 21d. The light emission patterns of the illumination lights of the inner illumination units 32a to 32d, that is, the central concentration pattern, are suitable for illumination inside the lumen organ, and particularly, inside the lumen organ having a relatively small internal space such as the small intestine. Suitable for lighting.

  On the other hand, the illumination light emitted by all the outer and inner illumination units 21a to 21d and 32a to 32d described above has a light intensity distribution as exemplified by a curve L12 in FIG. That is, the light intensity of the illumination light of all the illumination units 21a to 21d and 32a to 32d is the light intensity distribution (see FIG. 5) of the illumination light of the outer illumination units 21a to 21d and the inner illumination units 32a to 32d. It is a combination of the light intensity distribution of the illumination light (see FIG. 15).

  The illumination light having a light intensity distribution as exemplified by the curve L12 in FIG. 16 includes the illumination width of the illumination light of the outer illumination units 21a to 21d and the inner illumination unit in the vicinity of the center of the imaging field of the imaging unit 22. It becomes what has the light intensity of 32a-32d illumination light. A light emission pattern of illumination light obtained by synthesizing illumination light of the outer illumination units 21a to 21d and illumination light of the inner illumination units 32a to 32d, that is, a synthesis pattern is suitable for illumination inside the luminal organ. It is suitable for illumination inside a hollow organ having a relatively large internal space such as the large intestine.

Here, the filter coefficients K3 _ij and K4 _ij corresponding to the central concentration pattern exemplified by the curve L11 in FIG. 15 are solid-state imaging when the reflected light from the subject illuminated by the illumination light of the central concentration pattern is received. It has a reciprocal relationship with the plate surface illuminance of the element 22b. For example, when the wall surface of the organ is illuminated with the illumination light having the central concentration pattern, the plate surface illuminance of the solid-state imaging device 22b has a distribution as illustrated by a curve L13 in FIG. In this case, the wall surface assumed filter coefficient K4 _ij corresponding to the central concentration pattern is a value on the curve L13 having a reciprocal relationship with the curve L11 indicating the light intensity distribution of the plate surface illuminance corresponding to the wall surface.

On the other hand, the filter coefficients K5 _ij and K6 _ij corresponding to the composite pattern exemplified by the curve L12 in FIG. 16 are those of the solid-state imaging device 22b when receiving the reflected light from the subject illuminated by the illumination light of this composite pattern. It has a reciprocal relationship with the plate surface illuminance. For example, when the wall surface of the organ is illuminated with the illumination light of such a composite pattern, the plate surface illuminance of the solid-state imaging device 22b has a distribution as illustrated by the curve L14 in FIG. In this case, the wall surface assumed filter coefficient K6 _ij corresponding to the combined pattern is a value on the curve L14 having an inverse relationship with the curve L12 indicating the light intensity distribution of the plate surface illuminance corresponding to the wall surface.

  Next, the operation of the capsule medical device 31 when controlling the amount of illumination light and the illumination pattern corresponding to the in-vivo image capturing scene will be described. FIG. 17 is a flowchart illustrating the processing procedure of the control unit of the capsule medical apparatus according to the second embodiment of the present invention. The control unit 35 of the capsule medical device 31 performs the processing procedure shown in FIG. 17 to determine an illumination pattern at the time of capturing an in-vivo image, and determines an imaging scene of the in-vivo image according to the determined illumination pattern. The amount of illumination light and the illumination pattern are controlled corresponding to the determined imaging scene.

  That is, as shown in FIG. 17, the control unit 35 first controls the illumination units 21 a to 21 d and 32 a to 32 d so as to illuminate the subject of the imaging unit 22 by irradiating the inside of the organ of the subject 1 with illumination light. In addition, the imaging unit 22 is controlled so as to capture an image of the subject illuminated by the illumination light, that is, an in-vivo image of the subject 1 (step S301). In step S301, the control unit 35 emits the illumination light of the light amount adjusted by the light amount adjustment unit 25d to the illumination unit group selected by the illumination selection unit 35e from the illumination units 21a to 21d and 32a to 32d. Control to emit light. Further, the control unit 35 acquires in-vivo image data for one frame based on the signal photoelectrically converted by the solid-state imaging device 22b, and receives an image signal including the in-vivo image data from the external receiving device 3 (see FIG. 1). The transmission unit 23 is controlled so as to be wirelessly transmitted.

Next, the control unit 35 determines an illumination pattern when the in-vivo image is captured in step S301. If the illumination pattern is a normal pattern (step S302, normal), the coefficient information 34a in the storage unit 24 is selected. Then, filter coefficients K1 _ij and K2 _ij corresponding to the normal pattern are read (step S303). Thereafter, the control unit 35 performs dimming processing for each imaging scene of the in-vivo image using the filter coefficients K1 _ij and K2 _ij read in step S303 (step S304).

  In step S304, the control unit 35 appropriately performs the same processing procedure as in steps S102 to S109 shown in FIG. 8 to determine the imaging scene of the in-vivo image when the illumination pattern is a normal pattern. The amount of illumination light is controlled corresponding to the captured scene. In this case, the scene determination unit 35b performs the same processing procedure as steps S201 to S205 shown in FIG. 9, and calculates the scene determination value B1 assumed for the lumen and the scene determination value B2 assumed for the wall surface, Based on the result of the comparison processing by the scene determination units B1 and B2, the imaging scene of the in-vivo image when the illumination pattern is a normal pattern is determined.

On the other hand, when the illumination pattern when the in-vivo image is captured in step S301 is the central concentration pattern (step S302, central concentration), the control unit 35 converts the coefficient information 34a in the storage unit 24 into the central concentration pattern. Corresponding filter coefficients K3 _ij and K4 _ij are read out (step S305). Thereafter, the control unit 35 performs dimming processing for each imaging scene of the in-vivo image using the filter coefficients K3 _ij and K4 _ij read in step S305 (step S306).

In step S306, the control unit 35 appropriately performs substantially the same processing procedure as in steps S102 to S109 shown in FIG. 8 to determine the in-vivo image capturing scene when the illumination pattern is a central concentration pattern. The amount of illumination light is controlled in accordance with the determined imaging scene. In this case, the scene discriminating unit 35b replaces the filter coefficients K1 _ij and K2 _ij in the first embodiment described above, and assumes the filter coefficient K3 _{ij for the} lumen portion corresponding to the central concentration pattern and the filter coefficient K4 _{ij for the} wall surface portion. Is used to perform the same processing procedure as steps S201 to S205 shown in FIG. Thereby, the scene discriminating unit 35b calculates the scene discriminating value B1 assumed for the lumen portion and the scene discriminating value B2 assumed for the wall surface portion when the illumination pattern is the central concentration pattern, and the scene discriminating units B1 and B2 Based on the result of the comparison process, the imaging scene of the in-vivo image when the illumination pattern is the central concentration pattern is determined.

On the other hand, when the illumination pattern when the in-vivo image is captured in step S301 is a composite pattern (step S302, composite), the control unit 35 selects a filter corresponding to the composite pattern from the coefficient information 34a in the storage unit 24. The coefficients K5 _ij and K6 _ij are read (step S307). Thereafter, the control unit 35 performs dimming processing for each imaging scene of the in-vivo image using the filter coefficients K5 _ij and K6 _ij read out in step S307 (step S308).

In step S308, the control unit 35 appropriately performs a processing procedure substantially similar to that in steps S102 to S109 shown in FIG. 8 to determine the in-vivo image capturing scene when the illumination pattern is a composite pattern. The amount of illumination light is controlled in accordance with the determined imaging scene. In this case, the scene discriminating unit 35b replaces the filter coefficients K1 _ij and K2 _ij in the first embodiment with the filter coefficients K5 _ij assumed for the lumen and the filter coefficients K6 _ij assumed for the wall surface corresponding to the composite pattern. The same processing procedure as steps S201 to S205 shown in FIG. 9 is used. Thereby, the scene discriminating unit 35b calculates the scene discriminating value B1 assumed for the lumen and the scene discriminating value B2 assumed for the wall surface when the illumination pattern is a composite pattern, and the scene discriminating units B1 and B2 are compared. Based on the result of the processing, the imaging scene of the in-vivo image when the illumination pattern is a composite pattern is determined.

  After executing any of the above-described steps S304, S306, and S308, the control unit 35 selects an illumination pattern corresponding to the determined imaging scene (step S309), and then returns to the above-described step S301. The processing procedure after S301 is repeated.

  In step S309, the illumination selection unit 35e corresponds to the captured scene determined by the scene determination unit 35b in any of steps S304, S306, and S308, from among all the illumination units 21a to 21d and 32a to 32d. An illumination unit group that should emit illumination light is selected. Specifically, when the imaging scene is a lumen part, the illumination selection unit 35e selects any one of the illumination units 32a to 32d and any of the illumination units 21a to 21d and 32a to 32d. When the selected scene is a wall surface, the outer illumination units 21a to 21d are selected. The illumination selection unit 35e achieves the illumination pattern selection process according to the in-vivo image capturing scene by selecting the illumination unit group that should emit illumination light in this way.

  Here, as described above, the control unit 35 that repeats steps S301 to S309 as appropriate determines the in-vivo image capturing scene for each of the plurality of illumination patterns, and determines the amount of illumination light and the illumination pattern corresponding to the determined imaging scene. Control. When the capsule medical device 31 including the control unit 35 moves along the digestive tract of the subject 1 and reaches the luminal organ, the capsular medical device 31 can be selected from a plurality of preset illumination patterns. Select an illumination pattern suitable for illumination (central concentration pattern or composite pattern), adjust the amount of light suitable for illumination of this luminal organ, and irradiate the subject with illumination light of this illumination pattern. The image of is taken. In addition, when the capsule medical device 31 faces the organ inner wall surface of the subject 1, the capsule medical device 31 selects an illumination pattern (normal pattern) suitable for illumination of the organ inner wall surface from a plurality of preset illumination patterns. Then, the light intensity is adjusted to be suitable for illumination of the inner wall surface of the organ, the illumination light of this illumination pattern is irradiated onto the subject, and an image of the inner wall portion of the organ is captured.

  As described above, in Embodiment 2 of the present invention, there are a plurality of types of illumination patterns of illumination light that illuminate the subject of the imaging unit, and in-vivo images are captured according to the illumination pattern when the in-vivo images are captured. The scene is discriminated, and the amount of illumination light and the illumination pattern are controlled corresponding to the discriminated imaging scene, and the others are configured in the same manner as in the first embodiment. For this reason, while enjoying the effect similar to Embodiment 1 mentioned above, the illumination pattern of illumination light can be adjusted to a suitable thing according to the change of the imaging scene inside a subject, and, thereby, appropriate brightness It is possible to realize a capsule medical device that can capture the in-vivo image more clearly.

In the first and second embodiments described above, a plurality of partial image areas set by dividing an in-vivo image into a grid shape are illustrated. However, the present invention is not limited to this, and a portion set in an in-vivo image for one frame. As long as there are a plurality of image regions, a region having a desired mode may be used. Specifically, the plurality of partial image areas set in the in-vivo image for one frame are divided into a frame shape from the central area of the in-vivo image toward the edge as shown in FIG. , A2,..., Ai, or partial image areas A1 to A5 set in the central area and the four corner areas of the in-vivo image as shown in FIG. As shown, it may be a partial image area A _ij set on a diagonal line of the in-vivo image.

  In the first and second embodiments described above, the scene discrimination value for each assumed imaging scene is multiplied by each average luminance value of a plurality of partial image regions in the in-vivo image and each filter coefficient corresponding to the assumed imaging scene. Although the ratio between the maximum value and the minimum value of each calculated multiplication value is calculated, the present invention is not limited to this, and the scene determination value for each assumed imaging scene exemplified in the above-described scene determination values K1 and K2 is as follows. It may be a standard deviation value of each multiplication value of the average luminance value and the filter coefficient, or may be a difference between the maximum value and the minimum value of the multiplication values of the average luminance value and the filter coefficient. .

  Furthermore, in Embodiments 1 and 2 described above, scene discrimination values are calculated for each assumed imaging scene such as the above-described lumen portion or wall surface portion, and in-vivo images are obtained based on the comparison processing results of the calculated scene discrimination values. However, the present invention is not limited to this, and a scene discrimination value corresponding to any one of the assumed imaging scenes may be calculated, and the calculated scene discrimination value may be compared with a preset threshold value. The in-vivo image capturing scene may be determined based on the result of the comparison process.

  In the first and second embodiments described above, the scene discrimination value is calculated using each filter coefficient corresponding to the assumed imaging scene. However, the present invention is not limited to this, and the in-vivo image is not used without using each filter coefficient. The scene discrimination value may be calculated using the average luminance values of the plurality of partial image areas. In this case, the scene discrimination value may be a ratio between the maximum value and the minimum value of the average luminance values of the partial image areas, or the standard deviation value of the average luminance values of the partial image areas. Alternatively, it may be a difference between the maximum value and the minimum value among the average luminance values of the partial image area.

Furthermore, in Embodiments 1 and 2 described above, the weighting coefficient W _ij is calculated in correspondence with the luminance range as illustrated in FIG. 4. However, the present invention is not limited to this, and a plurality of partial image regions in the in-vivo image are used. Each of the average brightness values is compared with a preset brightness threshold, a predetermined weighting coefficient is assigned to the average brightness value exceeding the brightness threshold, and the weighting coefficient for the average brightness value below the brightness threshold is set to zero. May be. In this case, the above-described luminance comparison value is calculated by averaging the integrated values obtained by integrating the multiplication values of the average luminance value exceeding the luminance threshold value and a predetermined weighting coefficient. Further, a weighting coefficient (= 1) may be assigned to the maximum value among the average luminance values of the plurality of partial image regions, and the weighting coefficient for the remaining average luminance values may be set to zero. In this case, the above-described luminance comparison value is a product of the weighting coefficient and the maximum value, that is, the maximum value among these average luminance values. By setting the weighting coefficient in this way, it is possible to increase the weighting of the average luminance value larger than the predetermined value among the average luminance values of the plurality of partial image regions in the in-vivo image.

  In the first and second embodiments described above, when it is determined that the imaging scene of the in-vivo image is a lumen, the average luminance value of all image regions of the in-vivo image for one frame is calculated as the expected luminance of the lumen. Although it was calculated as a comparison value, the present invention is not limited to this, and the luminance comparison value assumed for the lumen portion is substantially the same as the calculation method of the luminance comparison value assumed for the wall surface portion described above. Each multiplication value obtained by multiplying each average luminance value and each weighting coefficient may be calculated, and the integrated value of the calculated multiplication values may be divided by the number of partial image areas. In this case, the weighting coefficient for calculating the luminance comparison value for the lumen portion may be different from the weighting coefficient for calculating the luminance comparison value for the wall surface portion. In this case, the weighting coefficient when calculating the luminance comparison value assumed for the lumen is set to a value that increases from the central region of the in-vivo image toward the edge region, and when calculating the luminance comparison value assumed for the wall surface portion. The weighting coefficient may be set to a value that decreases from the central region of the in-vivo image toward the edge region.

  Furthermore, in Embodiments 1 and 2 described above, the capsule medical device that captures an in-vivo image of the subject 1 is exemplified. However, the present invention is not limited thereto, and the in-vivo information of the subject is not limited to this. As long as it acquires at least in-vivo images, it may be a capsule medical device that further measures the pH value or temperature inside the subject as in-vivo information, and further detects the state of biological tissue as in-vivo information It may be a capsule medical device. In addition, the capsule medical device according to the present invention may be a capsule medical device further provided with a function of spraying or injecting a drug inside a subject, and further collects a substance in a living body such as a living tissue. It may be a capsule medical device.

  Moreover, in Embodiment 1 mentioned above, although the four illumination parts 21a-21d were illustrated as an illumination light source which illuminates the internal organ of a subject, not only this but the capsule type medical device concerning Embodiment 1 is as follows. It is only necessary to include at least one illumination unit that can emit illumination light that illuminates the subject of the imaging unit 22, and the number of the illumination units arranged is not particularly limited to four.

  Furthermore, in Embodiment 2 mentioned above, as an illumination light source which illuminates the inside of a subject's organ, four illumination parts 21a-21d arrange | positioned outside and four illumination parts 32a-32d arrange | positioned inside are illustrated. However, the present invention is not limited to this, and the capsule medical device according to the second embodiment may include a plurality of illumination units that can switch a plurality of types of illumination patterns when the subject of the imaging unit 22 is illuminated. In this case, the arrangement quantity of the inner illumination unit is not particularly limited to four, and the arrangement quantity of the outer illumination unit is not particularly limited to four.

It is a schematic diagram which shows one structural example of the in-vivo image acquisition system concerning Embodiment 1 of this invention. It is a schematic diagram which shows one structural example of the capsule type medical device concerning Embodiment 1 of this invention. FIG. 3 is a schematic view illustrating a capsule medical device viewed from a direction D shown in FIG. 2. It is a schematic diagram which shows one specific example of weighting information. It is a schematic diagram which illustrates the light intensity distribution of the illumination light which the illumination part of a capsule type medical device light-emits. It is a schematic diagram for demonstrating the filter coefficient at the time of assuming a lumen part as an imaging scene. It is a schematic diagram for demonstrating the filter coefficient at the time of assuming a wall surface part as an imaging scene. It is a flowchart which illustrates the process sequence of the control part of the capsule type medical device concerning Embodiment 1 of this invention. It is a flowchart which illustrates the process sequence until it achieves the imaging scene discrimination | determination process of step S103 shown in FIG. It is a mimetic diagram which illustrates the state where a capsule type medical device picturizes an in-vivo image inside a hollow organ. It is a schematic diagram which shows a specific example of the filter coefficient of a lumen part assumption, and the filter coefficient of a wall part assumption. It is a schematic diagram which illustrates the state which a capsule medical device images an in-vivo image facing an inner wall surface of an organ. It is a schematic diagram which shows one structural example of the capsule type medical device concerning Embodiment 2 of this invention. It is a schematic diagram which illustrates the capsule type medical device seen from the direction D shown in FIG. It is a schematic diagram which illustrates the centralized illumination pattern by an inner side illumination part. It is a schematic diagram which illustrates the synthetic | combination type illumination pattern by all the illumination parts. It is a flowchart which illustrates the process sequence of the control part of the capsule type medical device concerning Embodiment 2 of this invention. It is a schematic diagram which shows another aspect 1 of the some partial image area | region set in the in-vivo image for 1 frame. It is a schematic diagram which shows another aspect 2 of the some partial image area | region set in the in-vivo image for 1 frame. It is a schematic diagram which shows another aspect 3 of the some partial image area | region set in the in-vivo image for 1 frame.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Subject 2,31 Capsule type medical device 3 Receiving device 3a-3h Receiving antenna 4 Image display device 5 Storage medium 15 Lumen organ 16 Organ inner wall surface 20 Capsule-type housing 20a Cylindrical housing 20b Dome-shaped housing 21a- 21b, 32a to 32d Illumination unit 22 Imaging unit 22a Optical system 22b Solid-state imaging device 23 Transmission unit 23a Transmission antenna 24 Storage unit 24a, 34a Coefficient information 24b Weighting information 24c Dimming information 25, 35 Control unit 25a Signal processing unit 25b, 35b Scene discrimination unit 25c Comparison value calculation unit 25d Light amount adjustment unit 26 Power supply unit 35e Illumination selection unit CL Center axis

Claims (7)

One or more illumination units that illuminate the subject by irradiating illumination light inside the organ of the subject;
An imaging unit that captures an image of a subject illuminated by the illumination light;
A control unit that determines an imaging scene of the image based on luminance information of an image captured by the imaging unit, and controls the amount of the illumination light corresponding to the determined imaging scene;
A capsule-type medical device comprising:   The control unit calculates the luminance information that is each average luminance value of a partial image region obtained by dividing the image into a plurality of regions, and determines a shooting scene of the image based on the calculated luminance information. The capsule medical device according to claim 1.   The control unit calculates a luminance comparison value based on each average luminance value of the plurality of partial image regions, compares the calculated luminance comparison value with a preset luminance target value, and the luminance comparison value is The light quantity of the illumination light is increased when the brightness target value is less than or equal to the brightness target value, and the light quantity of the illumination light is decreased when the brightness comparison value is larger than the brightness target value. The capsule medical device according to 1.   The capsule medical device according to claim 3, wherein the control unit switches the calculation method of the luminance comparison value corresponding to the imaging scene of the image.   When the luminance change in the screen of the image is less than a predetermined reference level, the control unit calculates the luminance comparison value that is an average luminance value of all image regions of the image, and In the case of an imaging scene in which the luminance change in the screen is equal to or higher than the predetermined reference level, the luminance comparison value is obtained by averaging each multiplication value of each weighting coefficient different from each other and the average luminance value corresponding to the luminance range. The capsule medical device according to claim 4, wherein the capsule medical device is calculated.   The capsule medical device according to claim 1, wherein the control unit switches a light emission pattern of the illumination light corresponding to a scene where the image is captured. The one or more illumination units are plural,
The capsule medical according to claim 6, wherein the control unit selects an illumination unit that emits illumination light of the light emission pattern from the plurality of illumination units corresponding to the imaging scene of the image. apparatus.

Images