JP2006212051A - Capsule type imaging device, in vivo imaging system and in vivo imaging method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capsule type imaging device capable of specifying a position and attitude in a living body, being miniaturized, and reducing power consumption. <P>SOLUTION: The capsule type imaging device for imaging the inside of the living body comprises: an imaging part provided with an imaging element for imaging an optical image inside the living body image-formed on the light receiving surface of the imaging element; a control chip provided with a magnetic heading sensor of at least three axes and a processing part for outputting magnetic field information capable of specifying the position and attitude of the capsule type imaging device on the basis of the output of the magnetic heading sensor; and a substrate on which the imaging part and the control chip are loaded and which is parallel to the light receiving surface of the imaging element. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tablet-type imaging device, an in-vivo imaging system, and an in-vivo imaging method.

  Conventionally, a method of imaging a living body with a swallowed tablet imaging device is known (for example, Patent Documents 1 and 2). In such an in-vivo imaging method, it is desirable that the position and posture of the tablet imaging device can be specified in vivo. If the position and orientation of the tablet imaging device in the living body can be specified, the imaging part can be specified after imaging, or a predetermined part in the living body can be imaged.

In the in-vivo imaging method described in Patent Document 1, a signal transmitted by a tablet-type imaging device is received by an antenna disposed near the body surface of a subject, the position of the tablet-type imaging device is specified based on the strength of the received signal, and the tablet The orientation of the tablet type imaging device is to be specified by detecting the direction of the magnetic field generated by the type imaging device outside the living body. In addition, in the in-vivo imaging method described in Patent Document 2, the position and posture of the tablet imaging device are specified by detecting the intensity and direction of the magnetic field generated by the tablet imaging device outside the living body.
However, in the in-vivo imaging methods described in Patent Documents 1 and 2, since it is necessary to provide the tablet-type imaging device with a magnetic field generator that generates a magnetic field, the tablet-type imaging device becomes larger and the power consumption of the tablet-type imaging device increases. There is a problem of doing.

JP 2004-41709 A JP 2000-23980 A

  The present invention has been made in view of the above problems. An object of the first invention is to provide a tablet-type imaging device capable of specifying a position and posture in a living body and reducing size and power consumption. The second invention provides an in-vivo imaging system using a tablet-type imaging device capable of downsizing and low power consumption, and capable of specifying the position and posture of the tablet-type imaging device. With the goal. A third invention is an in-vivo imaging method using a tablet imaging device capable of miniaturization and low power consumption, and provides an in-vivo imaging method capable of specifying the position and posture of a tablet imaging device. With the goal.

(1) A tablet-type imaging device according to a first invention for achieving the above object is a tablet-type imaging device that images a living body, has an imaging element, and forms an image on a light receiving surface of the imaging element. Based on the output of the magnetic azimuth sensor, an imaging unit that picks up an in-vivo optical image, at least a triaxial magnetic azimuth sensor, and magnetic field information that can specify the position and orientation of the tablet imaging device A control chip having a processing unit, and a substrate on which the imaging unit and the control chip are mounted and parallel to the light receiving surface of the imaging element.
The tablet-type imaging device according to the present invention includes at least a three-axis magnetic orientation sensor, and the processing unit outputs magnetic field information based on the output of the magnetic orientation sensor, so that the position and orientation of the tablet-type imaging device in the living body are specified. can do. Therefore, according to the present invention, it is possible to specify an imaging position and an imaging direction after imaging, or to image a predetermined part in a living body.
Moreover, the magnetic field generation part for generating the magnetic field applied to a magnetic direction sensor can be arrange | positioned outside the living body. Therefore, for example, it is not necessary to provide a magnet as in the tablet-type imaging device described in Patent Document 1 or a coil as in the tablet-type imaging device described in Patent Document 2, so that the tablet-type imaging according to the present invention. The device can be reduced in size and power consumption.
The magnetic direction sensor and the processing unit are incorporated in a single control chip, and the imaging unit and the control chip are mounted on a single substrate. Therefore, the tablet-type imaging device can be downsized compared to the case where the magnetic orientation sensor and the processing unit are incorporated in different chips or the case where the imaging unit and the control chip are mounted on different substrates. Can do.
The substrate is parallel to the light receiving surface of the image sensor. Therefore, when the substrate is not parallel to the light receiving surface of the image sensor, for example, the tablet-type imaging device can be downsized as compared with the case where the substrate is perpendicular to the light receiving surface of the image sensor.

(2) The image sensor may further include a temperature sensor that outputs a temperature signal capable of specifying the temperature inside the living body, and the imaging unit may image the inside of the living body in accordance with an imaging instruction generated based on the temperature signal.
The temperature of an abnormal part in a living body is often different from the temperature of a normal part. In the tablet-type imaging device according to the present invention, the imaging unit images the inside of the living body in accordance with the imaging instruction generated based on the temperature signal, so that it is possible to prevent an abnormal part in the living body from being overlooked. For example, according to the tablet-type imaging device of the present invention, it is possible to automatically image a region where the in-vivo temperature is within a predetermined temperature range, or to prompt the operator to perform an imaging operation when the in-vivo temperature is within the predetermined temperature range. Can be displayed.

(3) The magnetic field detection element of the magnetic orientation sensor may be a magnetoresistive element.
In general, the magnetoresistive element is small. Therefore, the magnetic direction sensor can be reduced in size by using a magnetoresistive element for the magnetic direction sensor.
(4) The magnetoresistive element may be a giant magnetoresistive element.
The magnetoresistive effect of the giant magnetoresistive element is larger than that of the ferromagnetic magnetoresistive element. That is, a magnetic direction sensor using a giant magnetoresistive element outputs an appropriate electrical signal corresponding to the magnetic field even when the applied magnetic field is weak. Therefore, according to the tablet-type imaging device of the present invention, it is possible to specify an appropriate position and posture in the living body.
A magnetic field sensor using a giant magnetoresistive element does not require a bias magnetic field. Therefore, according to the present invention, the power consumption of the tablet imaging device can be reduced.

(5) The image sensor may be a CMOS area image sensor.
The CMOS area image sensor can be manufactured by a general integrated circuit manufacturing process. Therefore, since not only the magnetic direction sensor and the processing unit but also the imaging element can be easily incorporated into the control chip, the tablet type imaging device can be downsized.
Further, since the CMOS area image sensor can be operated with a single power source, it is advantageous for reducing the power consumption of the tablet imaging device 1.

(6) You may further provide the metal housing | casing which accommodates the said board | substrate, the said imaging part, and the said control chip.
When the temperature in the apparatus rises, the tablet imaging apparatus may not operate normally. In particular, when a magnetoresistive element is used as the magnetic field detection element of the magnetic azimuth sensor, the output of the magnetoresistive element has a temperature-dependent characteristic, and therefore there is a possibility that the appropriate position and orientation of the tablet imaging device cannot be specified. However, according to the tablet-type imaging device according to the present invention, since the metal casing having higher thermal conductivity than other solids is provided, the temperature rise in the device can be suppressed.

(7) An in-vivo imaging system according to a second invention for achieving the above object includes a tablet-type imaging device according to the first invention, and a first magnetic field generator that is arranged outside the living body and generates a first magnetic field. And a second magnetic field generator that is disposed outside the living body and is spaced apart from the first magnetic field generator, and generates the second magnetic field, and the first magnetic field or the second magnetic field is generated in a time-sharing manner. And a magnetic field control means for generating the second magnetic field generator.

(8) An acquisition unit that is arranged outside the living body and acquires the magnetic field information by communication, and is generated based on an output in a state where the first magnetic field of the magnetic orientation sensor is generated outside the living body. Specification means for specifying the position and orientation of the tablet imaging device based on the magnetic field information and the magnetic field information generated based on the output of the magnetic orientation sensor in the state where the second magnetic field is generated And may be further provided.
(9) The first magnetic field generation unit may include a first coil, and the second magnetic field generation unit may include a second coil disposed so that an axis is orthogonal to the axis of the first coil. .

(10) An in-vivo imaging system according to a third invention for achieving the above object includes a step of causing the subject to swallow the tablet-type imaging device according to the first invention, and generating a first magnetic field arranged outside the living body. The first magnetic field or the second magnetic field is generated in a time-sharing manner between a first magnetic field generation unit and a second magnetic field generation unit that is arranged outside the living body and generates a second magnetic field apart from the first magnetic field generation unit. A magnetic field control step, the magnetic field information generated based on the output of the magnetic direction sensor in a state where the first magnetic field is generated in the magnetic field control step, and the second magnetic field is generated in the magnetic field control step. Identifying the position and orientation of the tablet-type imaging device based on the magnetic field information generated based on the output of the magnetic orientation sensor in a state where the imaging is performed, and causing the imaging unit to image the inside of the living body Stages, Including.

  It should be noted that the order of each operation of the method described in the claims is not limited to the order of description as long as there is no technical obstruction factor, and may be executed in any order, or may be executed simultaneously. Also good.

Hereinafter, embodiments of the present invention will be described based on a plurality of examples. In each of the embodiments, the component having the same reference sign corresponds to the component of the other embodiment having the reference sign.
(First Example)
FIG. 2 is a schematic diagram of the in-vivo imaging system 3 according to the first embodiment of the present invention. The in-vivo imaging system 3 includes a tablet-type imaging device 1 and a master device 2.
The tablet-type imaging device 1 is swallowed by the subject 4 and images the in-vivo of the subject 4. The in-vivo imaging system 3 causes the tablet imaging device 1 to measure the magnetic field (see arrows 300 and 302) generated by the master device 2 attached to the subject 4, and based on the measurement result, the tablet imaging device in vivo. 1 position and posture are specified. Therefore, according to the in-vivo imaging system 3, it is possible to specify an imaging site after imaging or to image a predetermined site in the subject 4's living body.

FIG. 1 is a block diagram of the tablet-type imaging device 1. FIG. 3 is a schematic diagram of the tablet imaging device 1. In FIG. 3, the RF unit 102, the modem unit 104, the CDMA unit 106, and the control unit 130 are not shown.
As shown in FIG. 3, the housing 144 locks the lens 112 and accommodates the components of the tablet imaging device 1 excluding the lens 112. The housing 144 is made of metal. In general, a metal has a higher thermal conductivity than other solids, so that an increase in temperature in the housing 144 can be suppressed. Note that the housing 144 may be formed of a material other than metal according to the specifications of the tablet imaging device 1.

  A wiring pattern (not shown) as the antenna 100 is formed on the substrate 140, and the components of the tablet-type imaging device 1 described below are mounted except for the antenna 100, the lens 112, and the semitransparent mirror 114. When the components of the tablet imaging device are mounted on a plurality of substrates, the tablet imaging device becomes larger and the assembly process of the tablet imaging device becomes complicated. However, in the tablet type imaging apparatus 1 according to the present embodiment, since the above-described components are mounted on the single substrate 140, the tablet type imaging apparatus 1 can be reduced in size, and the assembly process of the tablet type imaging apparatus 1 is simplified. Can be The antenna 100 may be a separate component from the substrate 140.

As illustrated in FIG. 1, the RF unit 102 includes a duplexer, an amplifier, a filter, and the like that allow a reception signal to pass through a circuit on the reception side and a transmission signal to pass through the antenna 100.
At the time of reception, the modem unit 104 demodulates the received signal with a demodulator, converts it to a digital signal with an A / D converter, and outputs the digital signal to the CDMA unit 106 as a baseband signal. At the time of transmission, the modem unit 104 converts the baseband signal output from the CDMA unit 106 into an analog signal by a D / A converter and then modulates the baseband signal to the RF unit 102 as a transmission signal. Output.

  The CDMA unit 106 separates or synthesizes a control signal and a data signal for communication between the tablet imaging device 1 and the master device 2, a circuit for performing diffusion processing or despreading processing by adding a diffusion code to the signal. For example, a circuit is provided. At the time of reception, the CDMA unit 106 performs despreading processing on the baseband signal output from the modulation / demodulation unit 104, and separates the signal after despreading processing into a control signal and a data signal. Further, the CDMA unit 106 at the time of transmission performs spreading processing after combining the control signal with the data signal. Then, the CDMA unit 106 outputs the signal after spreading processing to the modem unit 104 as a baseband signal.

  The imaging unit 108 includes a CMOS area image sensor 110 (see FIG. 3) as an imaging element, an A / D converter (not shown), and the like, and images the inside of a living body. As shown in FIG. 3, the imaging unit 108 is mounted on the substrate 140 so that the light receiving surface 110 a of the CMOS area image sensor 110 is parallel to the substrate 140. Here, the size in the direction parallel to the light receiving surface 110a of the CMOS area image sensor 110 tends to be larger than the size of other components. However, in the tablet-type imaging device 1 according to the present embodiment, since the CMOS area image sensor 110 is mounted on the substrate 140 with the light receiving surface 110a parallel to the substrate 140 as described above, the tablet-type imaging device 1 is downsized. be able to.

  The CMOS area image sensor 110 includes photoelectric conversion elements, amplification elements, and the like that are discretely arranged in a two-dimensional space. The CMOS area image sensor 110 converts an in-vivo optical image formed on the light receiving surface 110a by the lens 112 and the semi-transparent mirror 114 into electric charges by a photoelectric conversion element. The CMOS area image sensor 110 accumulates the charge for each photoelectric conversion element for a certain period of time and outputs an electrical signal corresponding to the amount of light received for each photoelectric conversion element. The imaging device may be a CCD (Charge Coupled Device) image sensor provided with a charge transfer device.

The illumination unit 116 illuminates the living body according to the timing at which the imaging unit 108 images the inside of the living body. Specifically, for example, the illumination unit 116 is a so-called flash that emits light at the moment when the imaging unit 108 images the inside of the living body. The light emitted from the illumination unit 116 passes through the translucent mirror 114 and the lens 112 to illuminate the inside of the living body.
As shown in FIG. 1, a sensor control unit 122 and a magnetic orientation sensor module 123 as a processing unit are incorporated in a sensor chip 120 as a control chip. The sensor chip 120 is preferably a small package such as a WLCSP (Wafer Level Chip Scale Package). If WLCSP is used, the sensor chip 120 can be made substantially the same size as the bare chip.

  The magnetic direction sensor module 123 includes a first magnetic direction sensor 124, a second magnetic direction sensor 125, and a third magnetic direction sensor 126, and their sensitivity directions are orthogonal to each other. That is, the magnetic direction sensor module 123 is a so-called three-axis magnetic direction sensor capable of measuring a three-dimensional magnetic field. The sensitivity directions of the first magnetic direction sensor 124, the second magnetic direction sensor 125, and the third magnetic direction sensor 126 need only be different from each other, and may not be orthogonal to each other. Further, the magnetic direction sensor module 123 may be composed of three or more magnetic direction sensors.

  The first magnetic direction sensor 124, the second magnetic direction sensor 125, and the third magnetic direction sensor 126 each have a GMR element (giant magnetoresistive element) as a magnetic field detection element. Here, a magnetic field sensor using a GMR element as a magnetic field detection element does not require a bias magnetic field. Therefore, the first magnetic direction sensor 124, the second magnetic direction sensor 125, and the third magnetic direction sensor 126 can be easily downsized. The magnetic field detecting element may be a magnetoresistive element such as a ferromagnetic magnetoresistive element or a magnetic tunnel effect element.

  The sensor control unit 122 includes an A / D converter, a register, and the like (not shown), and acquires a magnetic field measurement result by the magnetic orientation sensor module 123. Specifically, the sensor control unit 122 converts the analog signal into digital data by sampling the analog signal output from the magnetic bearing sensor module 123 at a predetermined period by an A / D converter, and stores the digital data in a register. To do. This digital data corresponds to “magnetic field information” recited in the claims. Hereinafter, the above-described digital data as the magnetic field information and the digital data correlated with the output of the magnetic orientation sensor module 223 of the master device 2 described later are referred to as magnetic field data. The sensor control unit 122 may specify the magnitude and direction of the magnetic field based on the magnetic data, and store data indicating the specified magnitude and direction of the magnetic field in a register. In this case, data representing the magnitude and direction of the magnetic field corresponds to “magnetic field information” recited in the claims.

The control unit 130 includes a CPU 132, a ROM 134, a RAM 136, and an in-vivo imaging program executed by the CPU 132.
The battery 142 supplies power to the above-described components that require power supply.

FIG. 4 is a block diagram of the master device 2.
The antenna 200, the RF unit 202, the modem unit 204, the CDMA unit 206, and the sensor chip 220 of the master device 2 are substantially the same as the RF unit 102, the modem unit 104, the CDMA unit 106, and the sensor chip 120 of the tablet imaging device 1, respectively. It is the same configuration.

The coil control unit 210 supplies a current to the first coil 211 and the second coil 212 in a time division manner according to control of the control unit 230, thereby generating a magnetic field in the two coils in a time division manner. The first coil 211 is disposed at a predetermined relative position with respect to the sensor chip 220. Specifically, the first coil 211 and the sensor chip 220 are accommodated in the main box 2a (see FIG. 2). The second coil 212 is disposed away from the first coil 211, and its axis is orthogonal to the axis of the first coil 211 (see arrows 300 and 302 shown in FIG. 2). Specifically, the second coil 212 is accommodated in the sub box 2b.
The first coil 211 and the second coil 212 only need to be able to apply magnetic fields in different directions to the tablet imaging device 1, and their axes need not be orthogonal. Hereinafter, the magnetic field generated by the first coil 211 is referred to as “first magnetic field”, and the magnetic field generated by the second coil 212 is referred to as “second magnetic field”. The first magnetic field and the second magnetic field are collectively referred to as “external magnetic field”.

The control unit 230 includes an imaging control program executed by the CPU 232, ROM 234, RAM 236, and CPU 232.
The interface unit 214 is an interface for connecting to a processing device for processing measurement results such as a PC (Personal Computer) or a storage device for storing measurement results such as an HDD (Hard Disk Drive). Specifically, the interface unit 214 is a USB (Universal Serial Bus) interface, an IEEE 1394 interface, or the like. Therefore, the in-vivo imaging system 3 may be a system including the above-described apparatus such as a PC.

FIG. 5 is a flowchart for explaining the operation of the in-vivo imaging system 3.
First, the in-vivo imaging system 3 causes the tablet-type imaging device 1 swallowed by the subject 4 to capture an image of the inside of the living body every predetermined time (see Steps S10 and S12). Specifically, the control unit 122 of the tablet imaging device 1 determines whether a predetermined time has elapsed. When the control unit 122 determines that the predetermined time has elapsed, the control unit 122 images the inside of the living body in cooperation with the imaging unit 108 and the illumination unit 116, and in cooperation with the CDMA unit 106, the modulation / demodulation unit 104, and the like. The image is transmitted to the master device 2.

Next, the in-vivo imaging system 3 identifies the position and posture of the tablet imaging device 1 (see step S14). Details will be described later.
Next, the in-vivo imaging system 3 stores the in-vivo image captured by the tablet imaging device 1 in association with the position and posture of the tablet imaging device 1 at the time of imaging (see step S16). Specifically, the master device 2 associates the in-vivo image with the position and posture of the tablet imaging device 1 and stores them in the RAM 236.

FIG. 6 is a sequence diagram of processing for specifying the position and posture of the tablet imaging device 1.
First, the master device 2 measures a magnetic field in a state where no external magnetic field is generated by the magnetic azimuth sensor module 223 (see step S100), and stores the measurement result (see step S102). Specifically, the control unit 230 reads the magnetic field data from the register of the sensor control unit 222 and stores the magnetic field data in the RAM 236. This magnetic field data correlates with a disturbance magnetic field such as geomagnetism. Hereinafter, this magnetic field data is referred to as “master side disturbance magnetic field data”.

  Next, the master device 2 causes the tablet-type imaging device 1 to measure the magnetic field in a state where no external magnetic field is generated by the method described below, and stores the measurement result. This magnetic field data is also used for the above-described correction processing, like the disturbance magnetic field data on the master side. Hereinafter, this magnetic field data is referred to as “tablet disturbance magnetic field data”.

  First, the master device 2 transmits an instruction for causing the tablet imaging device 1 to measure a magnetic field (hereinafter referred to as a magnetic field measurement instruction) (see step S104). Specifically, the control unit 230 transmits a magnetic field measurement instruction from the antenna 200 to the tablet imaging device 1 in cooperation with the CDMA unit 206, the modulation / demodulation unit 204, and the like. Next, the tablet imaging device 1 measures the magnetic field by the magnetic orientation sensor module 123 in accordance with the magnetic field measurement instruction transmitted from the master device 2 (see step S106). Specifically, when receiving a magnetic field measurement instruction in cooperation with the modem unit 104, the CDMA unit 106, etc., the control unit 130 reads the disturbance magnetic field data on the tablet side from the register of the sensor control unit 122. Then, the control unit 130 cooperates with the CDMA unit 106, the modulation / demodulation unit 104, and the like to transmit the disturbance magnetic field data on the tablet side from the antenna 100 to the master device 2 (see step S108). Next, the master device 2 receives the disturbance magnetic field data on the tablet side in cooperation with the modem unit 204, the CDMA unit 206, etc., and stores the received disturbance magnetic field data on the tablet side in the RAM 236 (see step S110). .

Next, the master device 2 causes the tablet imaging device 1 to measure the magnetic field in a state where the first magnetic field is generated by the method described below, and stores the measurement result. Hereinafter, this magnetic field data is referred to as “first magnetic field data”.
First, the master device 2 controls the coil control unit 210 to supply a current to the first coil 211 to generate a first magnetic field in the first coil 211 (see step S112), and to input a magnetic field measurement instruction to the tablet-type imaging. It transmits toward the apparatus 1 (refer step S114). When receiving the magnetic field measurement instruction transmitted from the master device 2, the tablet imaging device 1 reads the first magnetic field data from the register of the sensor control unit 122 (see step S <b> 116), and transmits the magnetic field data to the master device 2. (See step S118). The master device 2 receives the first magnetic field data transmitted from the tablet imaging device 1, and stores the magnetic field data in the RAM 236 (see step S120).

Next, the master device 2 measures the magnetic field data in a state where the second magnetic field is generated by the magnetic direction sensor module 223 by the same method as the processing for acquiring the disturbance magnetic field data on the master side described above, and obtains the measurement result. Store (see steps S122 to 126). Hereinafter, this magnetic field data is referred to as “second magnetic field data on the master side”.
Next, the master device 2 causes the tablet-type imaging device 1 to measure the magnetic field data in a state in which the second magnetic field is generated by the same method as the process of acquiring the first magnetic field data described above, and stores the measurement result. (See steps S128 to 134). Hereinafter, this magnetic field data is referred to as “second magnetic field data on the tablet side”.

Next, the master device 2 specifies the position and posture of the tablet imaging device 1 based on the plurality of magnetic field data (see step S136). Hereinafter, this process will be described with reference to FIG.
First, the master device 2 performs correction processing for removing the influence of a disturbance magnetic field such as geomagnetism on the first magnetic field data, the second magnetic field data on the master side, and the second magnetic field data on the tablet side (see step S200). . Specifically, the control unit 230 subtracts the value of the disturbance magnetic field data on the master side from the value of the second magnetic field data on the master side. Similarly, the control unit 230 subtracts the value of the disturbance magnetic field data on the tablet side from the value of the first magnetic field data and the value of the second magnetic field data on the tablet side. Hereinafter, the magnetic field data not particularly described indicates the corrected magnetic field data. Note that the above-described correction processing is not necessary in an environment where the influence of the disturbance magnetic field can be ignored.

  Next, the master device 2 specifies the relative position of the first coil 211 with respect to the second coil 212 based on the master-side second magnetic field data (see step S202). Specifically, the control unit 230 specifies the magnitude and direction of the second magnetic field applied to the magnetic orientation sensor module 223 based on the second magnetic field data on the master side, and based on the magnitude and direction of the second magnetic field. The relative position of the magnetic direction sensor module 223 with respect to the second coil 212 is specified. Here, as described above, the first coil 211 is disposed at a predetermined relative position with respect to the sensor chip 220 on which the magnetic orientation sensor module 223 is mounted. That is, the relative position of the first coil 211 with respect to the magnetic orientation sensor module 223 is known. The control unit 230 determines the relative position of the first coil 211 with respect to the second coil 212 based on the relative position of the magnetic direction sensor module 223 with respect to the second coil 212 and the relative position of the first coil 211 with respect to the magnetic direction sensor module 223. Identify. In addition, when the relative position of the first coil 211 with respect to the second coil 212 is unchanged and the relative position of the first coil 211 with respect to the second coil 212 can be stored in the in-vivo imaging system 3 in advance. A process for specifying the relative position is not necessary.

Next, the master device 2 specifies the distance between the tablet imaging device 1 and the first coil 211 and the relative posture of the tablet imaging device 1 with respect to the first coil 211 based on the first magnetic field data. (See step S204). Specifically, the control unit 230 specifies the magnitude and direction of the first magnetic field applied to the magnetic orientation sensor module 123 based on the first magnetic field data. Then, the control unit 230 specifies the distance between the tablet imaging device 1 and the first coil 211 based on the magnitude of the first magnetic field, and the first coil 211 of the tablet imaging device 1 based on the direction of the first magnetic field. Identify relative posture with respect to.
Next, the master device 2 determines the distance between the tablet imaging device 1 and the second coil 212 and the relative posture of the tablet imaging device 1 with respect to the second coil 212 in the same manner as in step S204. The identification is performed based on the second magnetic field data on the tablet side (see step S206).

  Next, the master device 2 determines the relative position of the first coil 211 with respect to the second coil 212, the distance between the tablet imaging device 1 and the first coil 211, the tablet imaging device 1 and the second coil 212. Based on the distance, a position candidate of the tablet imaging device 1 is specified (see step S208). As shown in FIG. 8, the relative position of the first coil 211 with respect to the second coil 212 (see arrow 304), the distance between the tablet imaging device 1 and the first coil 211 (see the spherical surface 306 indicated by the dotted line), If the distance between the tablet-type imaging device 1 and the second coil 212 (see the spherical surface 308 indicated by the dotted line) is determined, the tablet-type imaging device 1 is located somewhere in the position candidates (see the circle 310 indicated by the dotted line). I understand. However, the position of the tablet imaging device 1 cannot be specified.

  Next, the master device 2 picks up the tablet image from the position candidates based on the relative posture with respect to the first coil 211 of the tablet image pickup device 1 and the relative posture with respect to the second coil 212 of the tablet image pickup device 1. The position of the device 1 is specified, and the posture of the tablet imaging device 1 is specified (see step S210). Specifically, the control unit 230 specifies the posture in which the relative posture with respect to the first coil 211 and the relative posture with respect to the second coil 212 of the tablet imaging device 1 coincide with each other as the posture of the tablet imaging device 1. .

According to the in-vivo imaging system 3 according to the first embodiment of the present invention described above, an in-vivo image, its imaging position and imaging direction are associated with each other and stored in the ROM 234, so that an imaging site is specified after imaging in the living body. be able to.
In addition, according to the in-vivo imaging system 3, since the inside of the living body is imaged every predetermined time, the tablet imaging device 1 can autonomously image the inside of the living body. In this way, the number of communications between the master device 2 and the tablet imaging device 1 can be reduced, so that the power consumption of the tablet imaging device 1 can be reduced.

  In addition, although the test subject 4 demonstrated swallowing one tablet type imaging device 1, you may swallow several tablet type imaging devices 1. FIG. When the number of times of imaging is large, the battery 142 of the tablet-type imaging device 1 is consumed and imaging becomes impossible. However, if a plurality of tablet imaging devices 1 are swallowed, the plurality of tablet imaging devices 1 can share imaging in the living body.

(Second embodiment)
FIG. 9 is a flowchart for explaining the operation of the in-vivo imaging system 3 according to the second embodiment. The in-vivo imaging system 3 according to the second embodiment images the inside of the living body every time the tablet type imaging device 1 moves a predetermined distance.
First, the master device 2 specifies the position and posture of the tablet imaging device 1 every predetermined time by the same processing as in the first embodiment (see step S14 in FIG. 5). Then, the master device 2 specifies the movement distance from the previous imaging of the tablet imaging device 1 based on the current position of the tablet imaging device 1 and the position of the tablet imaging device 1 at the previous imaging (step). (See S20). When the movement distance reaches a predetermined distance, the master device 2 causes the tablet-type imaging device 1 to image the inside of the living body (see step S22 and step S12 in FIG. 5), and when the captured biological image and the tablet-type imaging device 1 capture an image. Are stored in the RAM 236 (see step S16 in FIG. 5).

According to the in-vivo imaging system 3 according to the second embodiment described above, since the inside of the living body is imaged every time the tablet-type imaging device 1 moves a predetermined distance, the vicinity of the site once imaged in the living body is imaged again. It can prevent, and can image the living body without waste. Therefore, according to the in-vivo imaging system 3 according to the second embodiment, the power consumption of the tablet imaging device 1 can be reduced.
The in-vivo imaging system 3 according to the second embodiment has been described as imaging the living body every time the tablet-type imaging device 1 moves a predetermined distance. However, every time the tablet-type imaging device 1 is positioned at a predetermined site in the living body. Alternatively, the inside of the living body may be imaged.

(Third embodiment)
FIG. 10 is a block diagram of the tablet imaging device 1 according to the third embodiment.
The tablet imaging apparatus 1 according to the third embodiment includes a temperature sensor 128. Specifically, the temperature sensor 128 is incorporated in the sensor chip 320 of the tablet imaging device 1. The configuration of the sensor chip 320 other than the temperature sensor 128 is substantially the same as that of the sensor chip 120 according to the first embodiment.
The temperature sensor 128 is a band gap reference type temperature sensor that detects the temperature based on the temperature characteristics of the transistor. The temperature sensor 128 outputs an analog signal correlated with the temperature of the sensor chip 320. This analog signal corresponds to the “temperature signal” recited in the claims. The temperature sensor 128 may not be incorporated in the sensor chip 320. In that case, the temperature sensor 128 is not limited to a band gap reference type temperature sensor. For example, the temperature sensor 128 may be a thermistor or the like.

  The sensor control unit 122 of the sensor chip 320 converts the analog signal output from the magnetic azimuth sensor module 123 and the analog signal output from the temperature sensor 128 into digital data by an A / D converter, and registers the digital data. To store. Hereinafter, digital data correlated with the analog signal output from the temperature sensor 128 is referred to as “temperature data”.

FIG. 11 is a flowchart for explaining the operation of the in-vivo imaging system 3 according to the third embodiment. The in-vivo imaging system 3 according to the third embodiment images in-vivo when there is an abnormality in the in-vivo temperature (hereinafter referred to as in-vivo temperature).
First, the in-vivo imaging system 3 specifies the position and posture of the tablet imaging device 1 by the same processing as in the first embodiment (see step S14 in FIG. 5).

  Next, the in-vivo imaging system 3 measures the in-vivo temperature every predetermined time by the method described below (see step S30). First, the tablet-type imaging device 1 measures the internal temperature every predetermined time. Specifically, the control unit 130 reads temperature data from a register of the sensor control unit 122. And the control part 130 specifies body temperature based on temperature information. More specifically, for example, a table indicating the correlation between the temperature of the sensor chip 320 and the living body temperature outside the housing 144 is stored in the ROM 134. And the control part 130 specifies the temperature corresponding to temperature information as internal temperature based on this table.

Next, the tablet imaging device 1 determines whether or not the internal temperature is within the abnormal temperature range (see step S32). Here, the abnormal temperature range is a temperature range indicated by an abnormal site such as an ulcer. When the temperature inside the body is within the abnormal temperature range, the tablet-type imaging device 1 images the inside of the living body and stores the in-vivo image and the position and posture of the tablet-type imaging device 1 at the time of imaging in the ROM 234 of the master device 2 (see FIG. 5 steps S12 and 16). At this time, the signal output for the control unit 130 of the tablet imaging device 1 to cause the imaging unit 108 to image the inside of the living body corresponds to the “imaging instruction” recited in the claims. On the other hand, when the internal temperature is outside the abnormal temperature range, the tablet-type imaging device 1 executes the processes of steps S20 to S22.
Since the processing from step S20 to S22 is substantially the same as the in-vivo imaging system 3 according to the second embodiment, the description thereof is omitted (see FIG. 9).

According to the in-vivo imaging system 3 according to the third embodiment described above, since an abnormal part in the living body estimated based on the living body temperature is imaged, the oversight of the abnormal part can be prevented.
In the in-vivo imaging system 3 according to the third embodiment, the tablet imaging device 1 autonomously images the inside of the living body when the in-body temperature is within the abnormal temperature range. However, the in-body temperature is within the abnormal temperature range. Sometimes, the operator may be prompted to perform an imaging operation by screen display or the like, and the inside of the living body may be imaged by the tablet imaging device 1 in accordance with the imaging operation of the operator.
In addition, although it has been described that the tablet imaging device 1 determines whether or not the internal temperature is within the abnormal temperature range, the master device 2 may be allowed to determine.

(Fourth embodiment)
FIG. 12 is a schematic diagram of a sensor chip 420 according to the fourth embodiment.
The sensor chip 420 according to the fourth embodiment incorporates not only the sensor control unit 122, the magnetic orientation sensor module 123, and the temperature sensor 128 but also a CMOS area image sensor 110 as an image sensor. Here, the CMOS area image sensor 110 can be manufactured by a general integrated circuit manufacturing process. Therefore, the CMOS area image sensor 110 can be easily integrated on one chip together with the sensor control unit 122, the magnetic orientation sensor module 123, and the temperature sensor 128.

FIG. 13 is a schematic diagram of the tablet-type imaging device 1 according to the fourth embodiment.
The sensor chip 420 is mounted on the surface of the substrate 140 opposite to the translucent mirror 114 and the illumination unit 116. The substrate 140 is formed with an opening 140 a that exposes the light receiving surface 110 a of the CMOS area image sensor 110. The in-vivo optical image passes through the opening 140a and is formed on the light receiving surface 110a of the CMOS area image sensor 110.

According to the tablet-type imaging device 1 according to the fourth embodiment described above, not only the sensor control unit 122, the magnetic orientation sensor module 123, and the temperature sensor 128 but also the CMOS area image sensor 110 is incorporated in one sensor chip 420. . Therefore, according to the tablet type imaging device 1 according to the fourth embodiment, the tablet type imaging device 1 can be downsized.
In addition, the sensor chip 420 is mounted on the surface of the substrate 140 opposite to the translucent mirror 114 and the illumination unit 116. That is, since the sensor chip 420 and other components can be distributed and mounted on both surfaces of the substrate 140, the tablet-type imaging device 1 can be reduced in size.

1 is a block diagram of a tablet imaging device according to a first embodiment of the present invention. 1 is a schematic diagram of an in-vivo imaging system according to a first embodiment of the present invention. 1 is a schematic diagram of a tablet imaging device according to a first embodiment of the present invention. 1 is a block diagram of a master device according to a first embodiment of the present invention. 1 is a flowchart of an in-vivo imaging system according to a first embodiment of the present invention. The sequence diagram of the process which specifies the position and attitude | position of a tablet type imaging device. The flowchart for demonstrating the process which specifies the position and attitude | position of a tablet type imaging device. The schematic diagram for demonstrating the process which specifies the position and attitude | position of a tablet type imaging device. The flowchart of the in-vivo imaging system by the 2nd Example of this invention. The block diagram of the tablet type imaging device which concerns on the 3rd Example of this invention. The flowchart of the in-vivo imaging system by the 3rd Example of this invention. The schematic diagram of the sensor chip concerning the 4th example of the present invention. The schematic diagram of the tablet-type imaging device which concerns on 4th Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tablet type imaging device, 2 Master apparatus, In-vivo imaging system, 108 Imaging part 110 CMOS area image sensor (imaging element), 110a Light-receiving surface (light-receiving surface of an image sensor), 120, 320, 420 Sensor chip (control chip) 122 sensor control unit (processing unit), 123 magnetic direction sensor module (magnetic direction sensor), 128 temperature sensor, 140 substrate, 144 housing, 211 first coil (magnetic field generation unit), 212 second coil (magnetic field generation unit) )

Claims (10)

A tablet-type imaging device for imaging a living body,
An image pickup unit that has an image pickup device and picks up an in-vivo optical image formed on the light receiving surface of the image pickup device;
A control chip having at least a three-axis magnetic azimuth sensor and a processing unit that outputs magnetic field information capable of specifying the position and orientation of the tablet imaging device based on the output of the magnetic azimuth sensor;
The imaging unit and the control chip are mounted, and a substrate parallel to the light receiving surface of the imaging element;
A tablet-type imaging device comprising: A temperature sensor that outputs a temperature signal capable of specifying the temperature in the living body;
The tablet imaging apparatus according to claim 1, wherein the imaging unit images the inside of a living body in accordance with an imaging instruction generated based on the temperature signal.   The tablet-type imaging device according to claim 1, wherein the magnetic field detection element of the magnetic orientation sensor is a magnetoresistive element.   The tablet-type imaging device according to claim 3, wherein the magnetoresistive element is a giant magnetoresistive element.   The tablet imaging device according to any one of claims 1 to 4, wherein the imaging device is a CMOS area image sensor.   The tablet-type imaging device according to claim 1, further comprising a metal housing that houses the substrate, the imaging unit, and the control chip. Tablet-type imaging device according to any one of claims 1 to 6,
A first magnetic field generator disposed outside the living body for generating a first magnetic field;
A second magnetic field generator that is arranged outside the living body and spaced apart from the first magnetic field generator, and generates a second magnetic field;
Magnetic field control means for generating the first magnetic field or the second magnetic field in a time division manner in the first magnetic field generator and the second magnetic field generator;
An in-vivo imaging system comprising: An acquisition means arranged outside the living body for acquiring the magnetic field information by communication;
The magnetic field information generated on the basis of the output of the magnetic azimuth sensor in the state of generating the first magnetic field and the output of the magnetic azimuth sensor in the state of generating the second magnetic field. Identifying means for identifying the position and orientation of the tablet imaging device based on the magnetic field information generated based on
The in-vivo imaging system according to claim 7, further comprising: The first magnetic field generator has a first coil,
9. The in-vivo imaging system according to claim 7, wherein the second magnetic field generation unit includes a second coil disposed such that an axis is orthogonal to an axis of the first coil. Allowing the subject to swallow the tablet imaging device according to any one of claims 1 to 6;
A first magnetic field generation unit that is arranged outside the living body and generates a first magnetic field, and a second magnetic field generation unit that is arranged outside the living body and generates a second magnetic field separated from the first magnetic field generation unit in a time-sharing manner. A magnetic field control step for generating the first magnetic field or the second magnetic field;
The magnetic field information generated based on the output of the magnetic direction sensor in a state where the first magnetic field is generated in the magnetic field control step, and the second magnetic field in a state where the second magnetic field is generated in the magnetic field control step. Identifying the position and orientation of the tablet imaging device based on the magnetic field information generated based on the output of the magnetic orientation sensor;
Causing the imaging unit to image a living body;
An in-vivo imaging method comprising:

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