JP5192591B2 - Capsule endoscope and operation control method of capsule endoscope - Google Patents

Description

The present invention relates to a capsule endoscope, and its operation control how to shoot an image in the subject.

  Recently, a medical examination using a capsule endoscope in which an image sensor, an illumination light source, and the like are incorporated in an ultra-small capsule is being put into practical use. In a medical examination using a capsule endoscope, first, the patient is swallowed by the capsule endoscope, and the object to be observed (inner wall surface of the human body duct) is illuminated with an illumination light source while being covered by the imaging device. Photograph the observation site. Then, the image data obtained thereby is wirelessly received by the receiving device, and is sequentially stored in a storage medium such as a flash memory provided in the receiving device. During or after the inspection, the image data is taken into an information management device such as a workstation, and the image displayed on the monitor is read.

  The number of times of imaging (frame rate) per unit time of the capsule endoscope is, for example, 2 fps (frame / second), and the imaging time is about 8 hours or more. Therefore, the amount of image data stored in the receiving device Will be enormous. Therefore, when interpreting an image, it takes a lot of time and labor to interpret all the captured images. Conventionally, various proposals have been made in order to reduce the burden of such interpretation (see Patent Documents 1 and 2).

  In the inventions described in Patent Documents 1 and 2, the movement speed of the capsule endoscope in the human body is detected using an acceleration sensor or a pressure sensor. When the movement speed is high, the frame rate is increased. It is lowered. Also, the degree of similarity is determined by comparing two image data such as the previous and next frames. If the degree of similarity is low, the display rate (number of displayed images per unit time) for display on the monitor is lowered (the image display time is reduced). If the similarity is high, the display rate is increased (the image display time is shortened).

  When the moving speed is slow or the similarity between the two compared images is high, the capsule endoscope may stay in one place for a long time. In this case, how many similar images with little change Will also be filmed. For this reason, as in Patent Documents 1 and 2, if the frame rate is lowered when the moving speed is slow, or the display rate is raised when the similarity between the two compared images is high, the number of similar images and similarity The number of times (or time) of interpreting an image to be read can be reduced, and the burden of interpretation can be reduced.

JP-T-2004-521626 JP 2006-238992 A

  Although the techniques described in Patent Documents 1 and 2 can certainly reduce the burden of interpretation, the power consumed when wirelessly transmitting image data from the capsule endoscope to the receiving device (consumption of the capsule endoscope) If the capsule endoscope is moved at a high speed and the frame rate is increased, the number of times of wireless transmission increases, which naturally increases the power consumption. When the power consumption increases, the battery is consumed quickly, and the battery runs out while the capsule endoscope is in the human body, resulting in a problem that subsequent images cannot be obtained.

  Also, considering the processing time required for image data transmission (which is significantly longer than the processing time required for imaging), image data is transmitted sequentially after imaging, so the next imaging is not completed before the image data transmission is completed. There is a limit to increasing the frame rate because it cannot be done. For this reason, even if the frame rate is increased to the highest frame rate that can be set with the current performance, there is a high possibility of overlooking a site (hereinafter referred to as a region of interest) where interpretation is focused, such as a lesion. In addition, when the frame rate is increased to the limit, power consumption increases. Further, if the region of interest is just touched when the frame rate is lowered, shooting is omitted, and there is a possibility that the region of interest may be overlooked as well.

  The present invention has been made in view of the above problems, and a capsule endoscope capable of reducing power consumption and processing time when image data is wirelessly transmitted, and a capsule endoscope operation control method. The purpose is to provide.

  It is another object of the present invention to provide an information management apparatus that can reduce the burden of interpretation.

  In order to achieve the above object, the present invention provides a capsule that is swallowed into a subject, and an image obtained by photographing an observation site in the subject with a built-in imaging means is transmitted to the outside by a transmission means. The endoscope includes a state detection unit that detects a state in the subject, and a pixel number conversion unit that converts the number of pixels of the image according to a detection result of the state detection unit. .

  The state detecting unit detects at least one of a moving speed, a moving distance, and an image similarity in the subject, and the pixel number converting unit detects the detection result and a preset threshold value. And the number of pixels is converted based on the comparison result.

  The pixel number conversion unit converts the number of pixels in at least two stages of the maximum number of pixels of the imaging unit and the number of pixels lower than the maximum number of pixels.

  The transmission means transmits the image to the outside by wireless transmission, and the imaging means and the transmission means do not leave a gap when the number of pixels is converted to the maximum number of pixels of the imaging means. If the number of pixels is converted to a number of pixels lower than the maximum number of pixels, the processing related to the shooting and the wireless transmission is performed, and the processing related to the shooting and the wireless transmission is generated at that time. It is preferable to pause the operation.

  The transmission unit transmits the image to the outside by wireless transmission, and the imaging unit and the transmission unit perform the shooting and the wireless communication without leaving a gap regardless of which of the pixel numbers is converted. It is preferable to execute processing related to transmission.

  The transmission means transmits the image to the outside by wireless transmission, and the imaging means and the transmission means do not leave a gap when the number of pixels is converted to the maximum number of pixels of the imaging means. If the number of pixels is converted to a number of pixels lower than the maximum number of pixels, the processing related to the shooting and the wireless transmission is performed, and the processing related to the shooting and the wireless transmission is generated at that time. Compare the detection result with a preset threshold value to determine whether to suspend the operation or execute the radio transmission with the number of pixels lower than the maximum number of pixels so as to fill the idle time. It is preferable to determine according to the result.

  In the case of executing the photographing for filling the free time, the pixel number conversion means converts the number of pixels by executing a pixel thinning process.

  The state detection unit detects a moving distance in the subject, and the imaging unit executes a first imaging at a constant distance interval according to the detection result, and performs a first imaging between the first imaging. In the first photographing, the pixel number conversion means converts the pixel number to the highest pixel number of the imaging means, and in the second photographing, the pixel number conversion means It is preferable to convert the number of pixels to a lower number of pixels.

  Further, the state detection unit includes a frame rate conversion unit that detects the similarity of the images and converts a frame rate of the imaging unit according to the detection result, and the imaging unit includes the frame rate conversion unit. When the third shooting is performed at the frame rate converted in step (b), and the frame rate is lower than the highest frame rate, a fourth shooting is performed between the third shootings, and the pixels The number conversion means converts the number of pixels into the maximum number of pixels of the imaging means in the third photographing, and the number of pixels is lower than the maximum number of pixels in the fourth photographing. It is preferable to convert.

  In the above case, the state detection unit detects at least one of a movement speed or a movement distance in the subject, and the frame rate conversion unit detects the fourth imaging according to the detection result. Convert the frame rate.

  The transmission means transmits the information on the number of pixels in association with the image.

  The pixel number conversion unit converts the pixel number by executing at least one of binning readout processing, pixel thinning processing, and averaging processing.

  Storage means for storing all images obtained by photographing with the imaging means is provided, and the transmission means collects and transmits the images stored in the storage means to the outside after being discharged and collected outside the body. Is preferred.

  In addition, the present invention provides an operation control of a capsule endoscope that is swallowed into a subject and an image obtained by photographing an observation site in the subject with a built-in imaging means is transmitted to the outside by a transmission means. A method comprising: a step of detecting a state in the subject by a state detection unit; and a step of converting the number of pixels of the image by a pixel number conversion unit according to a detection result of the state detection unit. It is characterized by.

  Furthermore, the present invention captures an image of a site to be observed in a subject obtained by a capsule endoscope swallowed in the subject, stores and manages the information, and displays information to be used for interpretation In the management apparatus, the capsule endoscope includes a state detection unit that detects a state in the subject, a pixel number conversion unit that converts the number of pixels of the image according to a detection result of the state detection unit, And a transmission unit that transmits the information on the number of pixels in association with the image, and further includes a display control unit that changes a display form of the image according to the information on the number of pixels.

  Preferably, the display control unit automatically displays the image having a specific number of pixels, and displays an image having a number of pixels different from the specific number of pixels according to an operation of the operation input unit. In this case, it is preferable that the specific number of pixels is the maximum number of pixels of the imaging unit.

  According to the capsule endoscope and the capsule endoscope operation control method of the present invention, since the number of pixels of the image is converted according to the state of the capsule endoscope in the subject, the number of pixels lower than usual. In this case, it is possible to reduce power consumption and processing time required when transmitting image data.

  If the power consumption is reduced, it is possible to avoid the problem that the battery runs out while the capsule endoscope is in the human body and the subsequent image cannot be obtained. Or the capacity | capacitance of a battery can be made smaller than before, and it can contribute to the cost reduction and size reduction of a capsule endoscope.

  Further, if the processing time is reduced, the reduced time can be used for standby time and photographing. When devoted to standby time, power consumption is further reduced, and when devoted to shooting, concerns such as oversight of a region of interest can be eliminated.

  According to the information management device of the present invention, since the display form of the image is changed according to the information on the number of pixels, it is possible to preferentially display an image having a high rare value, and to reduce the burden of interpretation. it can.

It is the schematic which shows the structure of a capsule endoscope system. It is sectional drawing which shows the internal structure of a capsule endoscope. It is a block diagram which shows the electric constitution of a capsule endoscope. It is a top view which shows schematic structure of CCD. It is a figure for demonstrating the outline of a binning read-out process. It is explanatory drawing which shows the mode of addition and rearrangement of R pixel. It is explanatory drawing which shows the mode of addition and rearrangement of B pixel. It is explanatory drawing which shows the mode of addition and rearrangement of G pixel. It is a block diagram which shows the electric constitution of a receiver. It is a block diagram which shows the electric constitution of a workstation. It is a figure which shows the example of a display of the image at the time of interpretation. It is a flowchart which shows the operation | movement procedure of a capsule endoscope. It is explanatory drawing which shows the relationship of the imaging and radio | wireless transmission processing time in each imaging | photography of the number of medium pixels and low pixel number normally. It is a figure for demonstrating 2nd embodiment which fills in the free time produced when medium resolution and low pixel count photography are set, and performs photography. It is a flowchart which shows the operation | movement procedure of the capsule endoscope in 2nd embodiment. It is a flowchart which shows the operation | movement procedure of the capsule endoscope in 3rd embodiment which performs imaging | photography with a low pixel number between regular imaging | photography at a fixed distance space | interval. It is a figure which shows the example of imaging | photography of 3rd embodiment. It is a figure which shows the example of imaging | photography of 3rd embodiment. It is a block diagram which shows the electrical constitution of the capsule endoscope of 4th embodiment provided with the similarity calculation circuit which calculates the similarity of the front and back frames. It is a flowchart which shows the operation | movement procedure of the capsule endoscope in 4th embodiment. It is a figure which shows the example of imaging | photography of 4th embodiment. It is a figure which shows the example of imaging | photography of 4th embodiment. It is a block diagram which shows another embodiment of a capsule endoscope.

  1, a capsule endoscope system 2 includes a capsule endoscope (Capsule Endoscope, hereinafter abbreviated as CE) 11 swallowed from the mouth of a patient 10 into a human body, and the patient 10 attached to a belt or the like. Receiving device 12 and a workstation (hereinafter abbreviated as WS) 13 for taking an image obtained by the CE 11 and performing interpretation by a doctor.

  The CE 11 images the inner wall surface of the conduit when passing through the human body conduit, and wirelessly transmits the image data obtained thereby to the receiving device 12 using the radio wave 14. The receiving device 12 includes a liquid crystal display (hereinafter abbreviated as LCD) 15 for displaying various setting screens, and an operation unit 16 for performing various settings. The receiving device 12 wirelessly receives the image data wirelessly transmitted from the CE 11 with the radio wave 14 and stores it.

  Transmission / reception of the radio wave 14 between the CE 11 and the receiving device 12 is performed by an antenna 39 (see FIGS. 2 and 3) provided in the CE 11 and a plurality of antennas mounted in the shield shirt 17 worn by the patient 10. 18 through. The antenna 18 has a built-in electric field strength measurement sensor 19 that measures the electric field strength of the radio wave 14 from the CE 11. The electric field strength measurement sensor 19 outputs the measurement result of the electric field strength to the position detection circuit 88 (see FIG. 9).

  The WS 13 includes a processor 20, an operation unit 21 such as a keyboard and a mouse, and a monitor 22. For example, the processor 20 is connected to the receiving device 12 via a USB cable 23 (which may be wireless communication such as infrared communication), and exchanges data with the receiving device 12. The processor 20 takes in the image data from the receiving device 12 during the examination by the CE 11 or after the examination is completed, and accumulates and manages the image data for each patient. In addition, a display image is generated from the image data and displayed on the monitor 22.

  In FIG. 2, the CE 11 includes a transparent front cover 30 and a rear cover 31 that is fitted to the front cover 30 to form a watertight space. Both the covers 30 and 31 are formed in a cylindrical shape whose front end or rear end has a substantially hemispherical shape.

  An imaging unit 34 including an objective optical system 32 for taking in image light of the observation site and a CCD 33 for imaging the image light of the observation site is incorporated in the space formed by both covers 30 and 31. In the CCD 33, the image light of the observation site incident from the objective optical system 32 is imaged on the imaging surface, and an imaging signal corresponding to this is output from each pixel.

  The objective optical system 32 is attached to a transparent convex optical dome 32a and a rear end of the optical dome 32a, and is tapered toward the rear end. The lens holder 32b becomes a lens 32c fixed to the lens holder 32b. The objective optical system 32 has, for example, an imaging range with a front viewing angle of 140 ° to 180 ° with the optical axis 35 as the central axis, and takes in an omnidirectional image of the observed site in this imaging range as image light.

  In both covers 30, 31, in addition to the imaging unit 34, an illumination light source unit 36 that irradiates light to the site to be observed, a transmission circuit 55, and a power supply circuit 57 (both see FIG. 3) are mounted. 37, a button-type battery 38, an antenna 39 for transmitting the radio wave 14, and the like are accommodated.

  In the following description, the direction parallel to the optical axis 35 from the rear cover 31 side to the front cover 30 side is defined as the F direction, and the opposite direction is defined as the R direction. When the CE 11 is moving with the F direction as the traveling direction, the CCD 33 images the front site to be observed. On the other hand, when the CE 11 is moving with the R direction as the traveling direction, the CCD 33 images the rear part to be observed.

  In FIG. 3, the CPU 50 comprehensively controls the overall operation of the CE 11. A ROM 51 and a RAM 52 are connected to the CPU 50. The ROM 51 stores various programs and data for controlling the operation of the CE 11. The CPU 50 reads necessary programs and data from the ROM 51, develops them in the RAM 52, and sequentially processes the read programs.

  A driver 53 and a signal processing circuit 54 are connected to the CCD 33. The driver 53 controls the operations of the CCD 33 and the signal processing circuit 54 so that shooting is performed at a predetermined frame rate (for example, 2 fps). The signal processing circuit 54 performs correlated double sampling, amplification, and A / D conversion on the imaging signal output from the CCD 33, and converts the imaging signal into digital image data. The converted image data is subjected to various image processing such as γ correction.

  A transmission circuit 55 is connected to the antenna 39. A modulation circuit 56 is connected to the transmission circuit 55, and the modulation circuit 56 is connected to the CPU 50. The modulation circuit 56 modulates the digital image data output from the signal processing circuit 54 into a radio wave 14 and outputs the modulated radio wave 14 to the transmission circuit 55. The transmission circuit 55 amplifies the radio wave 14 from the modulation circuit 56 and performs band-pass filtering, and then outputs it to the antenna 39.

  The power supply circuit 57 supplies the power of the battery 38 to each part of the CE 11. Reference numeral 58 denotes a driver for controlling the driving of the illumination light source unit 36 under the control of the CPU 50.

The acceleration sensor 59 measures the acceleration of the CE 11 in the F and R directions, and outputs the measurement result to the integration circuit 60. The acceleration sensor 59 is set so that the measurement result is positive when the CE 11 is moving with the F direction as the traveling direction and accelerating or decelerating while moving with the R direction as the traveling direction. On the contrary, when the CE 11 moves with the F direction as the traveling direction and decelerates, or moves with the R direction as the traveling direction and accelerates, the measurement result of the acceleration sensor 59 becomes negative. The measurement result of the acceleration sensor 59 is 0 when the CE 11 is moving at a constant speed in the F and R directions, or stationary or moving perpendicular to the F and R directions. The integration circuit 60 integrates the measurement result of the acceleration sensor 59 once at an appropriate time interval to obtain the moving speed V ₀ of the CE 11 in the F and R directions. The integration circuit 60 outputs the obtained data of the moving speed V ₀ to the CPU 50.

The CPU 50 integrates the moving speed V ₀ sequentially output from the integrating circuit 60 from the start of acceleration measurement, and calculates the moving speed V of the CE 11 at that time. When the CE 11 is moving with the F direction as the traveling direction, the moving speed V is positive. When the CE 11 is stationary or is moving perpendicular to the F and R directions, the moving speed V is zero. Further, when the CE 11 is moving with the R direction as the traveling direction, the moving speed V is negative.

For example, the CPU 50 calculates the absolute value | V | of the calculated moving speed V and the first and second threshold values set in advance every five times of photographing (may be every fixed time (for example, every second)). Compare TH ₁ and TH ₂ (TH ₁ > TH ₂ ). The CPU 50 converts the number of pixels of the image obtained by the CCD 33 in three stages of P _max , P _mid , and P _low according to the comparison result between the absolute value | V | of the moving speed and the threshold values TH ₁ and TH _2. A control signal for output to the driver 53. The driver 53 drives the CCD 33 based on each control signal from the CPU 50.

That is, when the absolute value | V | of the moving speed is equal to or greater than the first threshold value TH ₁ (| V | ≧ TH ₁ ), the CPU 50 performs shooting with the maximum pixel number P _max of the CCD 33 (hereinafter referred to as normal shooting). ). When the absolute value | V | of the moving speed is less than the first threshold value TH ₁ and equal to or greater than the second threshold value TH ₂ (TH ₂ ≦ | V | <TH ₁ ), the CPU 50 determines the number of pixels P _max. Shooting is performed with a lower pixel number P _mid (hereinafter referred to as “medium pixel number shooting”). Further, when the absolute value | V | of the moving speed is less than the second threshold TH ₂ (| V | <TH ₂ ), or the absolute value | V | of the moving speed is 0 (| V | = In the case of 0, that is, when the CE 11 is stopped), the CPU 50 causes photographing with a pixel number P _low that is lower than the pixel number P _mid (hereinafter referred to as low pixel number photographing).

  The CPU 50 outputs pixel number information (hereinafter referred to as pixel number information) to the modulation circuit 56. The pixel number information output to the modulation circuit 56 is modulated into the radio wave 14 together with the image data, amplified by the transmission circuit 55 and band-pass filtered, and then wirelessly transmitted from the antenna 39.

  Here, before moving on to the description of the method for converting the number of pixels, the schematic configuration of the CCD 33 will be described. In FIG. 4, the CCD 33 has a plurality of light receiving elements 70 arranged in a two-dimensional square lattice along the vertical direction V and the horizontal direction H. The light receiving element 70 is, for example, a pn junction type diode (photodiode), and converts incident light into a signal charge by photoelectric conversion and accumulates it.

  One of a red filter, a green filter, and a blue filter (represented by R, G, and B, respectively) is provided on the objective optical system 32 side of the light receiving element 70. The light receiving element 70 receives light of a color component corresponding to each color filter and constitutes a pixel 71 of each color of R, G, and B. In each color filter, the G pixels 71 are arranged in a checkered pattern, the row in which the R pixels 71 are arranged between the G pixels 71 arranged in the horizontal direction H, and the B pixel 71 instead of the R pixel 71. A so-called Bayer arrangement is adopted in which the rows in which are arranged are alternately arranged in the vertical direction V.

  Each column of the light receiving elements 70 is provided with a vertical charge transfer path (hereinafter abbreviated as VCCD) 72. The light receiving element 70 and the VCCD 72 are connected via a read gate 73. The VCCD 72 transfers the signal charge read from the light receiving element 70 through the read gate 73 in the vertical direction V.

  A line memory (hereinafter abbreviated as LM) 74 is connected to the end of each VCCD 72, and a horizontal charge transfer path (hereinafter abbreviated as HCCD) 75 is connected to the LM 74. The LM 74 sequentially receives the signal charges of the pixels 71 for one row from each VCCD 72, and selectively transfers the signal charges to the HCCD 75 (for example, all the rows or one column). The HCCD 75 transfers the signal charge read from the LM 74 in the horizontal direction H.

  An output amplifier 76 is provided at the end of the HCCD 75. The output amplifier 76 is composed of an FD (floating diffusion) amplifier, sequentially receives signal charges from the HCCD 75, converts the signal charges into voltage signals (imaging signals) by charge-voltage conversion, and outputs them.

  In the present embodiment, binning readout processing is used as a method for converting the number of pixels. In the binning readout process, signal charges of two or more pixels 71 are added on the VCCD 72 or the HCCD 75 when the signal charges are transferred by the VCCD 72 or the HCCD 75. Since the signal charge of two or more pixels 71 is added to form a signal representing one pixel, the data capacity of the final image data can be greatly reduced, and the apparent sensitivity of the CCD 33 is also improved. .

The binning reading process will be conceptually described with reference to FIGS. First, in FIG. 5, attention is focused on 16 pixels 71 of 4 × 4 (R, B4, G8). In this case, as shown in FIG. 6, the R pixels R ₁ and R ₂ in the first column and the R pixels R ₃ and R ₄ in the third column are added on the VCCD 72, respectively, and R ₁ R ₂ , Let R ₃ R ₄ . These are added on the HCCD 75 to obtain R ₁ R ₂ R ₃ R ₄ .

Similarly, as shown in FIG. 7, the B pixels B ₁ and B ₂ in the second column and the B pixels B ₃ and B ₄ in the fourth column are added on the VCCD 72, respectively, and B ₁ B ₂ , B ₃ B ₄ are added on the HCCD 75 to obtain B ₁ B ₂ B ₃ B ₄ . Further, as shown in FIG. 8, the G pixels G ₁ and G ₂ in the first column, the G pixels G ₃ and G ₄ in the second column, and the G pixels G ₅ and G ₆ in the third column, The G pixels G ₇ and G _{8 in the} fourth row are also added on the VCCD 72 and the HCCD 75 to obtain G ₁ G ₂ G ₃ G ₄ and G ₅ G ₆ G ₇ G ₈ .

Then, as shown on the right side of FIGS. 6-8, R ₁ R ₂ R ₃ R ₄ , B ₁ B ₂ B ₃ B ₄ , G ₁ G ₂ G ₃ G ₄ , and G ₅ G ₆ G ₇ G ₈ Are rearranged into 2 × 2 four addition pixels 77 having R, G, and B pixels. During normal photographing, the signal charges of all the pixels 71 are individually read out to form an image with the _maximum number of pixels P _max of the CCD 33. By such pixel addition and rearrangement, the number of pixels becomes the number of pixels P _max. 1/4 of this. In the present embodiment, as an example, the pixel number P _mid at the time of shooting the number of medium pixels is set to ¼ of the pixel number P _max , and the pixel number P _low at the time of shooting of the low pixel number is set to 1/16 of the number of pixels P _max . For details of the binning readout process, refer to Japanese Patent Laid-Open No. 2000-350099.

  In FIG. 9, the CPU 80 comprehensively controls the overall operation of the receiving device 12. A ROM 82 and a RAM 83 are connected to the CPU 80 via a bus 81. The ROM 82 stores various programs and data for controlling the operation of the receiving device 12. The CPU 80 reads out necessary programs and data from the ROM 82, develops them in the RAM 83, and sequentially processes the read programs. Further, the CPU 80 operates each unit of the receiving device 12 in accordance with an operation input signal from the operation unit 16.

  A receiving circuit 84 is connected to the antenna 18. A demodulation circuit 85 is connected to the reception circuit 84. The reception circuit 84 amplifies the radio wave 14 received via the antenna 18 and performs band-pass filtering, and then outputs it to the demodulation circuit 85. The demodulation circuit 85 demodulates the radio wave 14 from the receiving device 12 into the original image data and pixel number information. The demodulated image data is output to the DSP 86 and the pixel number information is output to the data storage 87.

  A DSP (Digital Signal Processor) 86 performs various signal processing on the image data from the demodulation circuit 85, and then outputs the image data to the data storage 87. The data storage 87 is composed of a flash memory having a storage capacity of about 1 GB, for example. The data storage 87 stores and stores the image data sequentially output from the DSP 86 and the pixel number information from the demodulation circuit 85 in association with each other.

  The position detection circuit 88 detects the current position of the CE 11 in the human body based on the measurement result of the electric field intensity of the radio wave 14 by the electric field intensity measurement sensor 19, and this detection result (hereinafter referred to as position information) is stored in the data storage 87. Output. The data storage 87 stores the position information from the position detection circuit 88 in association with the image data from the DSP 86 together with the pixel number information.

  In addition, as a specific method for detecting the position of the CE 11 in the human body, for example, an electric field intensity distribution of the radio wave 14 received by the plurality of antennas 18 corresponding to the position of the CE 11 in the human body is obtained by experiments in advance. A data table in which the relationship between the position and the electric field intensity distribution is associated is stored in the ROM 82 in advance. Then, the measurement result of the electric field strength measurement sensor 19 is compared with the electric field strength distribution of the data table, and the position of the corresponding CE 11 is read from the data table.

  Alternatively, the amount of arrival time deviation of the radio wave 14 to each antenna 18, that is, the phase difference of the radio wave 14 may be detected and the position may be detected based on this. In this case, the phase difference of the radio wave 14 represents the relative positional relationship (distance) between each antenna 18 and the CE 11. The position detection circuit 88 detects the position of the CE 11 by converting the phase difference of the radio wave 14 into the distance between each antenna 18 and the CE 11 using an appropriate conversion formula or data table. Furthermore, the position of the CE 11 may be detected based on the principle of triangulation by detecting the arrival directions of the radio waves 14 to at least two antennas 18 and using the distance between the two antennas 18 as a baseline length.

  In addition to the above components, the bus 81 includes a driver 89 that performs display control of the LCD 15, a communication I / F 91 that mediates data exchange with the processor 20 via the USB connector 90, and the power of the battery 92 of the receiving device 12. A power supply circuit 93 to be supplied to each unit is connected.

  In FIG. 10, the CPU 100 comprehensively controls the overall operation of the WS 13. The CPU 100 communicates with the driver 102 that performs display control of the monitor 22 via the bus 101 and the communication I that receives the image data from the receiving device 12 via the data exchange with the receiving device 12 via the USB connector 103. / F104, a data storage 105 for storing and accumulating image data from the receiving device 12, and a RAM 106 are connected.

  In addition to the image data, the data storage 105 stores various programs and data necessary for the operation of the WS 13, and a program of support software that supports doctor interpretation. The RAM 106 temporarily stores data read from the data storage 105 and intermediate data generated by various arithmetic processes.

  When the support software is launched, a work window 110 as shown in FIG. 11 is displayed on the monitor 22, for example. When a doctor operates the operation unit 21 on the work window 110, image display / editing, examination information input, and the like can be performed. In the work window 110, areas 112 to 114 are provided in addition to an area 111 on which patient information describing the name and age of the patient 10 and examination information such as an examination date are displayed.

A simple anatomical diagram 115 of the human body is displayed in the area 112, and a schematic movement trajectory 116 of the CE 11 derived from the position information is displayed in the anatomical diagram 115. Of the image data stored in the data storage 105, an image of the number of pixels P _max obtained by normal shooting is continuously displayed in the area 113. Further, in the number of pixels before and after the image of the pixel number P _max, the number of pixels obtained by the low pixel number imaging P _mid, also the image of P _low, a suitable number between the image display pixel number P _max Inserted. The image display in the area 113 can be played back, paused, and stopped by operating the cursor 118 on the control bar 117 provided at the bottom. Note that the shooting location on the movement locus 116 and the region 113 are connected by a dotted line 119 so that the shooting location of the image currently displayed in the region 113 can be visually specified.

In the region 114, before and after the image of the pixel number P _max currently displayed in the region 113, the images of the pixel numbers P _mid and P _low obtained by the middle pixel number photographing and the low pixel number photographing are stationary one by one. Displayed. Similar to the case of the area 113, the image display of the area 114 can be reproduced, paused, and stopped by operating the control bar 120. The distribution of the images to be displayed in the areas 113 and 114 is performed with reference to the pixel number information. Note that an image having the number of pixels P _max may be inserted into the region 114 as well. Further, the display time of the image having the pixel number P _max may be longer than that of the image having the pixel numbers P _mid and P _low . Further, in anticipation of the case where the number of future pixels P _max further increases and the number of pixels P _mid corresponds to the current number of pixels P _max , an image of the number of pixels P _mid is displayed in the region 113 as a moving image, contrary to the above case. Then, an image having the number of pixels P _max may be displayed in the region 114 as a still image.

  Next, a processing procedure when performing an examination with the capsule endoscope system 2 configured as described above will be described with reference to a flowchart of FIG. First, as a preparation before the examination, the doctor attaches the receiving device 12, the shield shirt 17, and the antenna 18 to the patient 10, turns on the CE 11, and causes the patient 10 to swallow the CE 11.

When the CE 11 is swallowed by the patient 10, as shown in S 10, a human body is observed by the CCD 33 in a normal shooting setting with a frame rate of 2 fps and the number of pixels P _max while the observation light source 36 is illuminated by the illumination light source unit 36. The inner wall surface of the body duct is imaged. At this time, the image light of the observed region in the human body incident from the objective optical system 32 is imaged on the imaging surface of the CCD 33, whereby an imaging signal is output from the CCD 33.

  In S11, the image pickup signal output from the CCD 33 is subjected to correlated double sampling, amplification, and A / D conversion by the signal processing circuit 54, converted into digital image data, and then subjected to various image processing. . The image data generated by the signal processing circuit 54 is output to the modulation circuit 56.

  In the modulation circuit 56, the digital image data output from the signal processing circuit 54 is modulated into the radio wave 14 together with the pixel number information from the CPU 50. In S 12, the modulated radio wave 14 is amplified and band-pass filtered by the transmission circuit 55 and then transmitted from the antenna 39.

  In the receiving device 12, when the radio wave 14 is received by the antenna 18, the radio wave 14 is amplified and band-pass filtered by the receiving circuit 84, and then demodulated to the original image data and pixel number information by the demodulation circuit 85. The demodulated image data is subjected to various signal processing by the DSP 86 and then output to the data storage 87 together with the pixel number information.

  At this time, the electric field intensity measurement sensor 19 measures the electric field intensity of the radio wave 14. Then, based on the measurement result of the electric field strength measurement sensor 19, the position of the CE 11 in the human body is detected by the position detection circuit 88. The detection result of the position detection circuit 88, that is, the position information is output to the data storage 87. The data storage 87 stores image data, pixel number information, and position information in association with each other.

  Furthermore, when the CE 11 is swallowed by the patient 10, measurement of acceleration by the acceleration sensor 59 is started. Based on the measurement result of the acceleration sensor 59, the CPU 50 calculates the moving speed V of the CE 11.

When five times of photographing by the normal photography is completed (yes in S13), as shown in S14, by CPU 50, first, the absolute value of the moving speed V | V | a, and the first threshold value TH ₁ is compared . When the absolute value | V | of the moving speed is greater than or equal to the first threshold TH ₁ (| V | ≧ TH ₁ , yes in S15), in S16, normal imaging with the number of pixels P _max is performed. A control signal is output from the CPU 50 to the driver 53. When the absolute value | V | of the moving speed is less than the first threshold value TH ₁ (| V | <TH ₁ , no in S15), the process proceeds to S17.

In S17, in turn, the absolute value of the moving speed V at CPU 50 | V | a, and the second threshold value TH ₂ are compared. If the absolute value | V | of the moving speed is greater than or equal to the second threshold TH ₂ (| V | ≧ TH ₂ (and | V | <TH ₁ ), yes in S18), the number of pixels P _{max in} S19 as the number of pixels captured in the pixel number _{P mid} is the number of pixels 1/4 is made, the control signal to the driver 53 is outputted from the CPU 50. When the absolute value | V | of the moving speed is less than the second threshold TH ₂ or when the absolute value | V | of the moving speed is 0 (| V | <TH ₂ , or | V | = 0) No in S18), as shown in S20, a control signal is output from the CPU 50 to the driver 53 so that a low pixel number photographing with a pixel number P _low which is 1/16 of the pixel number P _max is performed. Is done.

In response to the control signal from the CPU 50, the CCD 53 is driven by the driver 53 in accordance with the set shooting, which is usually the shooting with the middle pixel count and the low pixel count. When normal shooting is set, the signal charges of all the pixels 71 are individually read out, and an image having the number of pixels P _max is generated. When the middle pixel count and the low pixel count shooting are set, a binning readout process is executed, and an image with the pixel counts P _mid and P _low is generated. When five shootings are completed with the set shooting, the CPU 50 again compares the absolute value | V | of the moving speed V with each of the threshold values TH ₁ and TH ₂ and sets the shooting according to the comparison result. Is done. These series of processes are continued until the inspection by the CE 11 is completed.

  After completion of the examination, the doctor connects the receiving device 12 and the processor 20 with the USB cable 23, and the image data stored in the data storage 87, the pixel number information associated therewith, and the position information are stored in the data storage 105 of the WS 13. Upload to. Then, in WS13, interpretation is performed using support software.

The doctor interprets the image centered on the image of the number of pixels _Pmax obtained by normal imaging continuously displayed in the region 113 while operating the control bar 117 as necessary. When a region of interest such as a lesion is found in the image displayed in the region 113, the control bar 117 is operated to temporarily stop the display of the region 113. Then, before or after the image of the pixel number P _max currently displayed in the region 113, an image of the pixel numbers P _mid and P _low obtained by the middle pixel number photographing and the low pixel number photographing one by one is displayed in the region 114. To display a still image and perform more detailed interpretation.

According to the first embodiment described above, when the moving speed of the CE 11 in the human body is relatively fast (| V | ≧ TH ₁ ), the maximum number of pixels P _max of the CCD 33 and the moving speed are medium ( (TH ₂ ≦ | V | <TH ₁ ) is an intermediate number of pixels P _mid , the movement speed is relatively slow, or the CE 11 is stopped (| V | <TH ₂ or | V | = 0) Since each image is taken with a _low number of pixels P _low , it is possible to reduce power consumption and processing time required for wirelessly transmitting image data.

More specifically, in FIG. 13, the time required for the image light of the site to be observed in the human body to be imaged on the imaging surface of the CCD 33 and for the digital image data to be output by the signal processing circuit 54 (hereinafter referred to as the image data). ,) t _p that imaging processing time is substantially the same regardless of the kind of shooting (the number of pixels).

On the other hand, the time required for the image data to be modulated by the modulation circuit 56 into the radio wave 14 and transmitted from the antenna 39 (hereinafter referred to as transmission processing time) t _t becomes longer as the capacity of the image data to be transmitted increases. For this reason, the transmission processing time t _t is maximized at the time of normal photographing where the number of pixels of the image is the maximum and the image data capacity is also the maximum, and the power consumption required for the transmission is also maximized. In normal shooting, the time obtained by adding the shooting processing time t _p and the transmission processing time t _t is the shooting time interval t _n (in this embodiment, since the frame rate is 2 fps, t _n = 0.5 seconds). Will be the same. Furthermore, it is designed so that the time obtained by adding the imaging processing time t _p and the transmission processing time t _t becomes the imaging time interval t _n .

When shooting with a medium number of pixels and a low number of pixels, which has a relatively low number of pixels and therefore a small amount of image data, the transmission processing time t _t is shorter and the power consumption required for transmission is less than when shooting normally. . Since the transmission processing time t _t is shorter when shooting the number of medium pixels and the number of low pixels than when shooting normally, if the shooting time interval t _n is constant, the shooting process is also transmitted within the shooting time interval t _n. processing can also free time t _b is not performed. At the time of shooting the number of middle pixels and the number of low pixels, a mode in which transmission is performed immediately after shooting as shown in the lower part of normal shooting and a state immediately after shooting as shown in the lowermost stage (here, only low pixel number shooting is shown as a representative). It is possible to adopt a mode in which an image captured last time is transmitted before the next imaging without transmitting.

The idle time t _b, CCD 33, the driver 53, each portion or related to shooting such as a signal processing circuit 54, transmitting circuit 55, to suspend the operation of each unit involved in the transmission of such modulation circuit 56, by the standby time to reduce power consumption Thus, the consumption of the battery 38 can be further suppressed, and the life of the CE 11 can be extended. If the longevity of the CE 11 is achieved, there is no possibility that the battery 38 runs out during the observation, the operation of the CE 11 is stopped, and a problem that shooting is lost occurs.

  Further, when the moving speed of the CE 11 in the human body is relatively fast, an image with a small number of similar parts in the front and rear frames and a different projected site to be projected is photographed, so that the rarity value of the image is high. On the other hand, when the moving speed is medium or relatively slow, or when the CE 11 is stopped, there are many similar parts in the front and back frames, and the images of the projected parts to be observed are almost the same or exactly the same. Compared to the former case, the rarity value of the image is low. Therefore, if shooting is performed with the number of pixels corresponding to the value of the image, the convenience of interpretation can be improved.

  Compared to shooting with a constant frame rate and number of pixels, the capacity of the image data is reduced, so the capacity of the data storage 87 can be reduced, and the component cost can be reduced.

Since the image of the pixel number P _max obtained by the normal photographing is displayed on the monitor 22 and the image of the middle pixel number P _min and the low pixel number P _low is displayed according to the operation, the amount of images handled at the time of interpretation is reduced, The burden on the doctor can be reduced.

Instead of setting the idle time t _b as a standby time, the idle time t _b is eliminated and the next shooting is executed immediately after transmission of the image data as in the second embodiment shown in FIG. Also good. That is, not only the number of pixels but also the shooting time interval t _n (that is, the frame rate) is dynamically changed according to the type of shooting.

If the example shown in FIG. 14 is applied as it is, it goes backward from the viewpoint of extending the life of the CE 11. Therefore, for example, when photographing a part where the moving speed is faster than other human body ducts, such as an esophagus that is extremely short in time, usually within 1 second, or an intestine whose moving speed is rapidly increased by peristaltic movement. In a limited manner, the number of pixels is reduced compared to that during normal shooting to reduce the shooting time interval t _n (increasing the frame rate), thereby increasing the number of shootings. The example described in the first embodiment is applied to other parts.

Specifically, in addition to the first and second threshold values TH ₁ and TH ₂ , a third threshold value TH ₃ (TH ₃ > TH ₁ ) is set in advance. Then, as shown in FIG. 15, after transmitting the image data by executing the photographing (S10 to S12), in S30, the absolute value of the moving speed | V | comparing and the third threshold value TH _3, moving speed When the absolute value | V | is equal to or greater than the third threshold TH ₃ (| V | ≧ TH ₃ , yes in S31), as shown in S32, the number of medium pixels or the number of low pixels shown in FIG. switch to the (no free time _{t b).} When the absolute value | V | of the moving speed is less than the third threshold value TH ₃ (| V | <TH ₃ , no in S31), the process depends on the process of the first embodiment (the processes after S15 are illustrated). (Omitted).

Alternatively, assuming that CE11 is swallowed by the patient 10 and passes through the esophagus immediately after the power supply of CE11 is turned on, imaging of the number of medium pixels or the number of low pixels shown in FIG. to execute the idle without time t _b), it may proceed to the processing of the first embodiment after a predetermined time has elapsed. The elapsed time from power-on may be measured with the built-in clock 50a (see FIG. 3) of the CPU 50 or the like. As described above, if the region where the moving speed is relatively high is used, the number of times of imaging is increased by changing the number of pixels and the imaging time interval t _n, and if only the number of pixels is changed for other regions, Spillage can be reduced and the life of CE11 can be extended.

  In the second embodiment, as a method of converting the number of pixels, the signal charges of all the pixels 71 are not read, but the signal charges of a specific pixel 71 are not read or discarded, and the pixels 71 are appropriately selected. It is preferable to employ a pixel thinning process for thinning out and generating an image. Compared with the binning readout process, the pixel decimation process is simpler and takes less time, so it is particularly suitable when it is desired to increase the number of shots by increasing the frame rate as in the second embodiment. .

  In the first and second embodiments, the trigger for changing the number of pixels and the photographing time interval is the moving speed of the CE 11, but the moving distance of the CE 11 may be used. In this case, for example, as the acceleration sensor 58, a triaxial acceleration sensor capable of measuring triaxial accelerations of X, Y, and Z is used, and F, R directions and biaxial accelerations orthogonal to the F, R directions are measured. To do. Then, the measurement result of the acceleration sensor 59 is integrated twice at an appropriate time interval by the integration circuit 60 to obtain the movement distance L of the CE 11, and data of the obtained movement distance L is output to the CPU 50.

Hereinafter, as in the first embodiment, when the increment (movement amount) ΔL of the movement distance L per unit time (or every specified number of photographing) is large (synonymous with the case where the movement speed is fast), the normal photographing is performed and the movement is performed. When the amount ΔL is small (synonymous with the case where the moving speed is slow), shooting is performed with the number of medium pixels or the number of low pixels. Or, as in the second embodiment, the relatively large portion moving amount ΔL is, the number of pixels in shown in FIG. 14, or to execute the low pixel number imaging (without idle time t _b), other portions are the The example described in one embodiment may be applied.

  Alternatively, as in the third embodiment shown in FIG. 16, every time the CE 11 moves a certain distance, normal shooting (corresponding to the first shooting) is executed, and low pixel count shooting (second shooting) is performed between them. (Equivalent to photographing) may be executed.

In FIG. 16, in the third embodiment, after shooting is performed and image data is transmitted (S10 to S12), in S40, the movement amount ΔL of CE11 starting from the previous normal shooting is set in advance. a fourth threshold TH ₄ are compared by CPU 50. When the movement amount ΔL is equal to or greater than the fourth threshold TH ₄ (ΔL ≧ TH ₄ , yes in S41), as shown in S42, normal shooting is set and shooting is performed with the number of pixels _Pmax. . When the movement amount ΔL is less than the fourth threshold TH ₄ (ΔL <TH ₄ , no in S41), as shown in S43, the low pixel number photographing is set, the pixel number P _low , and a predetermined frame rate Shooting is performed at (for example, 2 fps).

Examples of photographing when the third embodiment is applied are shown in FIGS. In FIG. 17 and FIG. 18, the horizontal axis represents the movement distance and time. First, in FIG. 17, normal shooting is performed at regular distance intervals, and low pixel count shooting is performed in the meantime. When the movement amount ΔL is large (right side), the time required to move a certain distance is short, so the number of times of shooting with a low number of pixels is less than when the movement amount ΔL is small (left side). In addition, as shown in FIG. 18, low pixel number shooting is repeated at a predetermined frame rate, that is, at a fixed shooting time interval t _n during normal shooting.

  If CE11 only performs normal imaging every time it moves a certain distance, if there is a region of interest such as a lesion in the meantime, the number of images in which the region of interest is captured is small, or in some cases There is a risk of oversight. On the other hand, in the third embodiment, since the image is secured by shooting with a low number of pixels even during the normal shooting, it is possible to reduce the concern that the region of interest is overlooked while suppressing the power consumption for data transmission as much as possible. it can. In addition, since there is a high possibility that one region of interest is contained in a plurality of images, it is possible to respond to a doctor's request to interpret one region of interest with a plurality of images in a multifaceted manner.

  The trigger for changing the number of pixels is not limited to the moving speed and moving distance of CE11. For example, the number of pixels may be changed according to the similarity of images as in the fourth embodiment shown in FIG.

  The CE 130 shown in FIG. 19 is provided with a similarity calculation circuit 131 that calculates the similarity between the preceding and following frames (for example, the image data transmitted last time and the image data transmitted this time). The similarity calculation circuit 131 includes, for example, a frame memory that stores the image data output from the signal processing circuit 54 for two frames of the preceding and following frames and sequentially rewrites the old image data every time the image data is output. The similarity calculation circuit 131 analyzes the shape, color, and the like of the site to be observed displayed on the front and back frames using a known image recognition technique, and calculates the similarity SI of the front and back frames based on the analysis result. . The similarity calculation circuit 131 outputs the calculated similarity SI data to the CPU 50. The similarity SI is low if the observed site projected on the front and back frames is different, and is high if the site is the same.

Also in this case, as in the first embodiment, when the similarity SI is low (when the movement speed is fast, the same as the case where the movement amount is large), normal shooting is performed, and when the similarity SI is high (when the movement speed is slow). The same meaning as when the amount of movement is small) is taken with the number of medium pixels or the number of low pixels. Alternatively, the second embodiment adopts, in the similarity SI is very low site, performed to make the number of times of photographing, the number of pixels in shown in FIG. 14, or low pixel number imaging (no idle time t _b) In addition, the examples described in the first embodiment may be applied to other parts.

  Alternatively, as shown in the flowchart of FIG. 20, the frame rate when the similarity SI is high as compared with the case where the similarity SI is low may be lowered and normal shooting (corresponding to the third shooting) may be executed. In this case, for the purpose of securing an image of a part that cannot be captured by normal imaging, low pixel count imaging (corresponding to the fourth imaging) is executed between normal imaging when the similarity SI is high.

In FIG. 20, after photographing and transmitting image data (S10 to S12), as shown in S50, the similarity calculation circuit 131 calculates the similarity SI of the preceding and following frames. In CPU 50, it receives the data of the similarity SI from the similarity calculating circuit 131, as shown in S51, and the fifth threshold value TH ₅ which is preset similarity SI are compared.

If the similarity SI is less than the fifth threshold TH ₅ (S <TH ₅ , no in S52), normal shooting and a high frame rate (for example, 8 fps) are set as shown in S53. . If the similarity SI is equal to or greater than the fifth threshold TH ₅ (S ≧ TH ₅ , yes in S52), the process proceeds to S54.

In S54, when the similarity SI is not equal to or greater than the fifth threshold TH ₅ continuously (for example, five times) (no in S54), the process proceeds to S53, where the similarity SI is the fifth threshold TH. _{As in} the case of less than ₅ , normal shooting and a high frame rate are set. On the other hand, if the similarity SI is equal to or greater than the fifth threshold value TH ₅ for a predetermined number of times (yes in S54 and 55), normal shooting and a low frame rate (for example, 1 fps) are performed as shown in S56. Is set. If the shooting time interval has not been opened by the amount specified by the low frame rate (no in S55), as shown in S57, low pixel number shooting is set and shooting is performed at a predetermined frame rate (for example, 4 fps). Executed. In other words, when normal shooting and a low frame rate are set, the next normal shooting is executed when the time interval of the shooting time specified by the low frame rate has elapsed since the previous normal shooting, and the low frame rate is set. Until the time of the shooting time interval defined in (2) elapses, shooting with a low number of pixels is executed at a predetermined frame rate.

An example of photographing when the fourth embodiment is applied is shown in FIG. In FIG. 21, the horizontal axis represents time. If the similarity SI is high (left side), the normal photographing is performed at a low frame rate, a predetermined frame rate in between them, that is, constant exposure time low pixel number imaging at intervals t _n repeats. When the similarity SI is low (right side), normal shooting is performed at a high frame rate.

  When the similarity SI is high and only normal shooting is executed at a low frame rate, the image of the image of the region of interest is captured just like when normal shooting is executed every time the CE 11 moves a certain distance. There are few numbers or there is a risk of oversight. On the other hand, in the fourth embodiment, an image is secured by shooting with a low number of pixels even during normal shooting at a low frame rate, so the same effect as in the third embodiment can be obtained.

  Note that the frame rate for shooting with a low number of pixels executed when the similarity SI is high is not limited to 4 fps exemplified above. For example, as shown in FIG. 22, the frame rate for photographing with a lower number of pixels may be lowered than in the example shown in FIG. In this case, although the number of times of photographing with the low pixel number is reduced, the power consumption can be suppressed as compared with the example shown in FIG.

  Further, the frame rate of low-pixel number imaging that is executed when the similarity SI is high may be changed according to the moving speed or moving distance of the CE 11. For example, when the moving speed of CE11 is 0 or close to 0 and CE11 stops or the moving speed of CE11 is extremely slow, the example shown in FIG. 22 is adopted, and the moving speed is faster than the former. When the moving speed is slow, the example shown in FIG. 21 is adopted. Alternatively, the frame rate of the low pixel number imaging performed when the similarity SI is high may be configured so that the doctor can set the CE 11 before swallowing the patient 11.

Note that the low pixel number shooting in the third and fourth embodiments means shooting with a reduced number of pixels compared to normal shooting, and the low pixel number shooting in the first and second embodiments means. Is different. In other words, the low-pixel number shooting in the third and fourth embodiments may be 1/4 of the pixel number P _max corresponding to the pixel number P _mid in the first and second embodiments, It may be 1/2 of the number of pixels P _max having a higher number of pixels.

  In this way, if the number of pixels is converted according to the state of the CE 11 in the human body (movement speed, movement distance, image similarity), various power consumption can be suppressed and the possibility of overlooking the region of interest can be reduced. It is possible to adopt a combination of modes. Although not particularly described in the above embodiment, when the photographing interval (frame rate) is changed, it is performed based on the built-in clock 50a of the CPU 50.

  Note that the number of pixels to be converted is not limited to two or three stages, but may be more than that. Further, although the CCD has been described as an example of the image pickup device, it may be a CMOS. In this case, the functions of the driver 53, the signal processing circuit 54, and the like are integrally included in the CMOS image sensor. Furthermore, in addition to the pixel number information and the position information, the operation time and the frame rate may be associated with the image data.

  Rather than transmitting image data for each shooting, the image data obtained by the shooting may be transmitted together after performing shooting several times. In addition, a storage device 141 corresponding to the data storage 87 is mounted as in the CE 140 shown in FIG. 23, and the data stored in the storage device 141 is externally replaced instead of each unit such as the modulation circuit 56 related to wireless transmission. The communication I / F 142 for transmission (both wired and wireless is possible) is provided, the CE 140 discharged outside the body is collected, and the data stored in the storage device 141 is collected together via the communication I / F 142 to the processor 20. It may be taken in. Also in this case, since the time and power required for communication are reduced if the number of pixels is reduced, the same effect as in the above embodiment can be obtained.

The thresholds TH _{1 to} TH ₅ to be compared with the moving speed, the moving distance, and the image similarity may not be fixed values, and may be configured to be settable by a doctor. In the above embodiment, the absolute value | V | of the moving speed V and the first to third threshold values TH _{1 are} taken every predetermined number of times or every predetermined time for the purpose of avoiding dizzying pixel number conversion. While comparing the to TH _3, remembering hysteresis characteristic to the comparison determining that the threshold may be performed pixel number conversion when the threshold ± alpha. Further, the arrangement of the pixels 71 of the CCD 33 and the binning readout processing method are not limited to the contents described in the above embodiment.

  In the above embodiment, the electric field strength measurement sensor 19 is used to obtain the position information. Instead, for example, a magnet is provided in the CE 11 and a Hall element is provided in the antenna 18, and the magnetic field strength by the magnet is determined by the Hall element. Based on the measurement result, the position detection circuit 88 may detect the position of the CE 11 in the human body. Further, for example, an image analysis unit that analyzes image data using a known image recognition technique is provided in the receiving device 12 without using the electric field strength measurement sensor 19 or the Hall element. The position of the CE 11 may be detected by analyzing the image data. In this case, for example, an image of a specific part of a typical organ is prepared as a template, and the position of CE11 is specified based on the degree of coincidence between this template and image data from CE11. In short, it is only necessary to know the position of the CE in the human body, and any method other than the example shown above may be used.

  Further, the method for measuring the moving speed and the moving distance is not limited to the aspect exemplified in the above embodiment. For example, the moving speed and the moving distance may be calculated from the position information and the operation time.

  In the above embodiment, the binning readout process has been described as an example. However, the present invention is not limited to this, and the above-described pixel thinning process, the average of the pixel values of the target pixel and the surrounding pixels, You may employ | adopt the averaging process used as a pixel value.

2 Capsule Endoscopy System 11, 130, 140 Capsule Endoscope (CE)
12 Receiver 13 Workstation (WS)
21 Operation unit 22 Monitor 33 CCD
34 Imaging unit 39 Antenna 50 CPU
53 Driver 55 Transmission Circuit 56 Modulation Circuit 59 Acceleration Sensor 60 Integration Circuit 80 CPU
87 Data storage 100 CPU
102 Driver 105 Data Storage 131 Similarity Calculation Circuit 141 Storage Device

Claims (10)

In a capsule endoscope that is swallowed into a subject, and an image obtained by photographing an observation site in the subject with a built-in imaging unit is transmitted to the outside by a transmission unit.
State detecting means for detecting the similarity between the frames before and after the image;
A pixel number converting means for converting the number of pixels of the image according to a detection result of the state detecting means;
Frame rate conversion means for converting the frame rate of the imaging means according to the detection result,
The imaging unit executes the first shooting at the frame rate converted by the frame rate conversion unit, and when the frame rate is lower than the maximum frame rate, the first shooting is performed between the first shootings. Perform a second shoot,
The pixel number conversion unit converts the pixel number to the maximum number of pixels of the imaging unit in the first photographing, and the pixel number is lower than the maximum pixel number in the second photographing. Capsule endoscope characterized by converting number. The state detection means detects at least one of a movement speed or a movement distance in the subject,
The capsule endoscope according to claim 1, wherein the frame rate conversion unit converts the frame rate of the second imaging according to the detection result. The transmission means transmits the image to the outside by wireless transmission,
When the number of pixels is converted into the maximum number of pixels of the imaging unit, the imaging unit and the transmission unit execute processing related to the shooting and the wireless transmission without leaving a gap,
2. When the number of pixels is converted to a number of pixels lower than the maximum number of pixels, the operation is paused in a free time of processing related to the imaging and the wireless transmission generated at that time. 2. The capsule endoscope according to 2. The transmission means transmits the image to the outside by wireless transmission,
4. The image pickup unit and the transmission unit execute processing related to the photographing and the wireless transmission without leaving a gap, regardless of which number of pixels has been converted. The capsule endoscope according to any one of the above. The transmission means transmits the image to the outside by wireless transmission,
When the number of pixels is converted into the maximum number of pixels of the imaging unit, the imaging unit and the transmission unit execute processing related to the shooting and the wireless transmission without leaving a gap,
When the number of pixels is converted to a number of pixels lower than the maximum number of pixels, the operation is stopped or the idle time is filled in the idle time of the processing related to the imaging and the wireless transmission generated at that time. The method of determining whether to perform the imaging with the number of pixels lower than the maximum number of pixels and the wireless transmission is determined according to a comparison result between the detection result and a preset threshold value. The capsule endoscope according to any one of 1 to 4.   The capsule endoscope according to claim 4 or 5, wherein the pixel number conversion means converts the number of pixels by executing a pixel thinning process.   6. The pixel number conversion unit according to claim 1, wherein the pixel number conversion unit converts the pixel number by executing at least one of binning readout processing, pixel thinning processing, and averaging processing. The capsule endoscope according to any one of the above.   The capsule endoscope according to any one of claims 1 to 7, wherein the transmission unit transmits the information on the number of pixels in association with the image. Comprising storage means for storing all images obtained by photographing with the imaging means;
The capsule endoscope according to any one of claims 1 to 8, wherein the transmission unit transmits the images stored in the storage unit together after being discharged and collected outside the body. An operation control method for a capsule endoscope in which an image obtained by swallowing into a subject and photographing an observation site in the subject with a built-in imaging means is transmitted to the outside by a transmission means,
Detecting the degree of similarity of the front and back frames of the image by the state detection means;
Converting the number of pixels of the image by a pixel number conversion unit according to the detection result of the state detection unit;
A frame rate conversion step of converting a frame rate of the imaging unit by a frame rate conversion unit according to the detection result;
In the imaging step by the imaging means, the first imaging is executed at the frame rate converted in the frame rate conversion step. When the frame rate is lowered below the maximum frame rate, the first imaging is performed. Perform a second shoot in between,
In the step of converting the number of pixels, in the first photographing, the number of pixels is converted to the maximum number of pixels of the imaging unit, and in the second photographing, the number of pixels is lower than the maximum number of pixels. An operation control method for a capsule endoscope, wherein the number of pixels is converted.

Images