JP2006075536A - Intra-patient introduction system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow credible position detection while suppressing an increase in power consumption in a position detection apparatus or the like which detects the position of a detection object, such as a capsule endoscope or the like, using a position detection magnetic field. <P>SOLUTION: The capsule endoscope 2 comprises an intra-patient information acquiring section 14 for acquiring intra-patient information, a signal treatment section 15 for carrying out a predetermined treatment with regard to the acquired intra-patient information, a magnetic field sensor 16 for detecting the position detection magnetic field and for outputting an electric signal according to the detected magnetic field, a radio transmitting section 19 for sending the intra-patient information and the magnetic field information by radio, a timing controlling section 21 for controlling the timing to drive the intra-patient information acquiring section 14, the magnetic field sensor 16 and the radio transmitting section 19, and a speed deriving section 28 for deriving a travel speed of the capsule endoscope 2. The timing control section 21 controls the timing to drive on the basis of the moving speed derived by the speed deriving section 28. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an intra-subject introduction apparatus that is introduced into a subject and moves within the subject, and a position of the intra-subject introduction apparatus within the subject using a position detection magnetic field that has position dependency with respect to intensity. The present invention relates to an in-subject introduction system provided with a position detection device for detecting the above.

  In recent years, in the field of endoscopes, swallowable capsule endoscopes have been proposed. This capsule endoscope is provided with an imaging function and a wireless communication function. The capsule endoscope is swallowed from the mouth of the subject for observation (examination) until it is spontaneously discharged until it is spontaneously discharged. It has the function of moving and capturing images sequentially.

  While moving inside the body cavity, image data captured inside the body by the capsule endoscope is sequentially transmitted to the outside by wireless communication and stored in a memory provided outside. By carrying a receiver having a wireless communication function and a memory function, the subject can freely act after swallowing the capsule endoscope and before being discharged. After the capsule endoscope is ejected, a doctor or a nurse can make a diagnosis by displaying an image of an organ on a display based on image data stored in a memory (see, for example, Patent Document 1). .)

  Further, a conventional capsule endoscope system has been proposed that includes a mechanism for detecting the position of the capsule endoscope in the body cavity. For example, a magnetic field having a position dependency with respect to strength is formed inside a subject to which a capsule endoscope is introduced, and the inside of the subject is determined based on the strength of the magnetic field detected by a magnetic field sensor built in the capsule endoscope. It is possible to detect the position of the capsule endoscope. In such a capsule endoscope system, in order to form a magnetic field, a configuration in which a predetermined coil is arranged outside the subject is adopted, and a magnetic field is generated inside the subject by flowing a predetermined current through the coil. Trying to form.

Japanese Patent Laid-Open No. 2003-19111

  However, the conventional capsule endoscope system including the position detection mechanism has a problem that power consumption in at least the capsule endoscope increases. Specifically, in the conventional capsule endoscope system, position detection is performed at regular time intervals, and the magnetic field sensor built in the capsule endoscope 2 and the transmission result of wirelessly transmitting the detection result of the magnetic field sensor are transmitted. There is a problem that the power consumption increases by the drive power of the mechanism.

  In particular, there is a premise that the capsule endoscope is preferably as small as possible in order to reduce the burden on the subject. Accordingly, a small battery or the like built in the capsule endoscope is usually used, and the amount of power to be held is usually limited. Therefore, the influence of the increase in power consumption in the capsule endoscope is larger than that in a normal electronic device, and the suppression of the increase in power consumption is very important in the capsule endoscope system.

  The present invention has been made in view of the above, and relates to a position detection device that detects the position of a detection target such as a capsule endoscope using a magnetic field for position detection, while suppressing an increase in power consumption. It is an object to realize an in-subject introduction system that enables reliable position detection.

  In order to solve the above-described problems and achieve the object, an in-subject introduction system according to claim 1 is introduced into a subject and moves inside the subject, and a predetermined position. An intra-subject introduction system comprising: a position detection device that detects a position of the intra-subject introduction device within the subject using a magnetic field for detection, wherein the intra-subject introduction device includes the subject A magnetic field sensor that detects the magnetic field for position detection in a region where the internal introduction device is located, a wireless transmission means that transmits a wireless signal including a detection result by the magnetic field sensor, and an intracorporeal introduction device in the subject. Timing control means for controlling the driving timing of the wireless transmission means and / or the magnetic field sensor based on a moving state, and the position detection device forms the magnetic field for position detection. Magnetic field forming means, receiving means for performing reception processing of a radio signal including a detection result by the magnetic field sensor, and introduction into the subject inside the subject based on the radio signal subjected to reception processing by the receiving means And a position deriving unit for deriving the position of the apparatus.

  According to the first aspect of the present invention, the in-subject introduction apparatus having the wireless transmission means and / or the timing control means for controlling the drive timing of the magnetic field sensor in accordance with the movement state is provided. Since information used for position detection is output at a proper timing, it is possible to perform reliable position detection while suppressing power consumption of the intra-subject introduction apparatus.

  Further, in the in-subject introduction system according to claim 2, in the above-described invention, the in-subject introduction apparatus further includes speed deriving means for deriving a movement speed of the in-subject introduction apparatus as the movement state, The timing control means controls the drive timing based on the moving speed derived by the speed deriving means.

  Further, in the in-subject introduction system according to claim 3, in the above invention, the timing control means sets the drive cycle of the wireless transmission means and / or the magnetic field sensor to a predetermined length when the moving speed is low. The driving cycle is set to a short cycle that is shorter than the long cycle when the moving speed is high.

  The in-subject introduction system according to claim 4 is the above-described invention, wherein the in-subject introduction apparatus further includes vibration detection means for detecting a vibration state of the in-subject introduction apparatus as the moving state, The timing control means controls the drive timing based on a vibration state detected by the vibration detection means.

  In the in-subject introduction system according to claim 5, in the above invention, the wireless signal transmitted by the wireless transmission unit further includes information on the drive timing, and the position detection device includes the wireless Magnetic field control means for controlling the magnetic field formation timing by the magnetic field formation means based on information related to the drive timing included in the signal is further provided.

  According to a sixth aspect of the present invention, in the in-subject introduction system according to the present invention, the position detection device is configured so that the in-subject introduction system is based on positions of the in-subject introduction device at a plurality of times derived by the position deriving means. A moving speed deriving unit for deriving a moving speed of the introducing device; and a transmitting unit for transmitting a radio signal including the moving speed derived by the moving speed deriving unit as information. A wireless receiving means for receiving the wireless signal transmitted by the transmitting means; and a moving speed of the in-subject introduction device derived based on the wireless signal received and processed by the wireless receiving means. And a moving speed deriving unit that outputs information related to the timing control means.

  According to a seventh aspect of the present invention, there is provided the in-subject introduction system according to the present invention, wherein the position detecting device controls a magnetic field formation timing by the magnetic field forming unit based on a moving speed derived by the speed deriving unit. Control means is further provided.

  The in-subject introduction system according to the present invention includes the in-subject introduction apparatus having the timing control means for controlling the drive timing of the wireless transmission means and / or the magnetic field sensor in accordance with the movement state. Since information used for position detection is output at a necessary timing, there is an effect that reliable position detection can be performed while suppressing power consumption of the in-subject introduction apparatus.

  Hereinafter, a position detection apparatus and an in-subject introduction system, which are the best modes for carrying out the present invention (hereinafter simply referred to as “embodiments”), will be described. Note that the drawings are schematic, and it should be noted that the relationship between the thickness and width of each part, the ratio of the thickness of each part, and the like are different from the actual ones. Of course, the part from which the relationship and ratio of a mutual dimension differ is contained.

(Embodiment 1)
First, the in-subject introduction system according to the first embodiment will be described. FIG. 1 is a schematic diagram illustrating the overall configuration of the intra-subject introduction system according to the first embodiment. As shown in FIG. 1, the in-subject introduction system according to the first embodiment includes a capsule endoscope 2 that is introduced into the subject 1 and moves along a passage route, and a capsule endoscope. A position detection device 3 that performs wireless communication with the endoscope 2 and detects a positional relationship between a target coordinate axis fixed to the capsule endoscope 2 and a reference coordinate axis fixed to the subject 1; In order to exchange information between the display device 4 that displays the contents of the radio signal transmitted from the capsule endoscope 2 and received by the position detection device 3, and between the position detection device 3 and the display device 4. The portable recording medium 5 is provided. As shown in FIG. 1, in the first embodiment, an object coordinate axis that is a coordinate axis that is formed by the X axis, the Y axis, and the Z axis and is fixed to the capsule endoscope 2, and the x axis, It is formed by the y-axis and the z-axis, is determined independently of the movement of the capsule endoscope 2, and specifically sets a reference coordinate axis that is a coordinate axis fixed with respect to the subject 1. The positional relationship of the target coordinate axis with respect to the reference coordinate axis is detected using the mechanism described below.

  The display device 4 is for displaying an in-vivo image captured by the capsule endoscope 2 received by the position detection device 3 and is based on data obtained by the portable recording medium 5. It has a configuration such as a workstation that performs image display. Specifically, the display device 4 may be configured to directly display an image or the like by a CRT display, a liquid crystal display, or the like, or may be configured to output an image or the like to another medium such as a printer.

  The portable recording medium 5 is detachable from the processing device 12 and the display device 4 to be described later, and has a structure capable of outputting and recording information when being attached to both. Specifically, the portable recording medium 5 is inserted into the processing device 12 while the capsule endoscope 2 is moving in the body cavity of the subject 1, and the target coordinate axis with respect to the in-subject image and the reference coordinate axis. The positional relationship is stored. Then, after the capsule endoscope 2 is ejected from the subject 1, the capsule endoscope 2 is taken out from the processing device 12 and inserted into the display device 4, and the recorded data is read out by the display device 4. When data is transferred between the processing device 12 and the display device 4 using a portable recording medium 5 such as a compact flash (registered trademark) memory, the processing device 12 and the display device 4 are connected by wire. Unlike the capsule endoscope 2, the subject 1 can freely move even when the capsule endoscope 2 is moving inside the subject 1.

  Next, the capsule endoscope 2 will be described. The capsule endoscope 2 functions as an example of a detection target in the claims. Specifically, the capsule endoscope 2 is introduced into the subject 1, acquires in-subject information while moving in the subject 1, and transmits a radio signal including the acquired in-subject information to the outside It has the function to transmit to. In addition, the capsule endoscope 2 has a magnetic field detection function for detecting a positional relationship, which will be described later, and has a configuration in which driving power is supplied from the outside. Specifically, a radio signal transmitted from the outside is received. It has a function of receiving and reproducing the received radio signal as drive power.

  FIG. 2 is a block diagram showing a configuration of the capsule endoscope 2. As shown in FIG. 2, the capsule endoscope 2 functions as a mechanism for acquiring in-subject information. In-subject information acquisition unit 14 for acquiring in-subject information and the acquired in-subject information And a signal processing unit 15 for performing predetermined processing. The capsule endoscope 2 detects a magnetic field as a magnetic field detection mechanism, outputs a magnetic signal corresponding to the detected magnetic field, an amplifying unit 17 for amplifying the output electric signal, and an amplification And an A / D converter 18 that converts the electrical signal output from the unit 17 into a digital signal.

  The in-subject information acquisition unit 14 is for acquiring in-subject information, that is, an in-subject image as image data in the subject in the first embodiment. Specifically, the in-subject information acquisition unit 14 is an LED 22 that functions as an illumination unit, an LED drive circuit 23 that controls driving of the LED 22, and an imaging unit that captures at least a part of a region illuminated by the LED 22. A functioning CCD 24 and a CCD driving circuit 25 for controlling the driving state of the CCD 24 are provided. In addition, as a specific structure of an illumination part and an imaging part, it is not essential to use LED and CCD, For example, it is good also as using CMOS etc. as an imaging part.

  The magnetic field sensor 16 is for detecting the direction and intensity of the magnetic field formed in the region where the capsule endoscope 2 is present. Specifically, the magnetic field sensor 16 is formed using, for example, an MI (Magneto Impedance) sensor. The MI sensor has a configuration in which, for example, an FeCoSiB amorphous wire is used as a magnetosensitive medium. When a high frequency current is applied to the magnetosensitive medium, the MI impedance of the magnetosensitive medium greatly changes due to an external magnetic field. The magnetic field strength is detected using the effect. In addition to the MI sensor, the magnetic field sensor 16 may be configured using, for example, an MRE (magnetoresistive effect) element, a GMR (giant magnetoresistive effect) magnetic sensor, or the like.

  As shown in FIG. 1, in the first embodiment, a target coordinate axis defined by the X axis, the Y axis, and the Z axis is assumed as the coordinate axis of the capsule endoscope 2 to be detected. Corresponding to the target coordinate axis, the magnetic field sensor 16 detects the magnetic field strengths of the X direction component, the Y direction component, and the Z direction component for the magnetic field formed in the region where the capsule endoscope 2 is located, It has a function of outputting an electrical signal corresponding to the magnetic field strength in the direction. The magnetic field strength component on the target coordinate axis detected by the magnetic field sensor 16 is transmitted to the position detection device 3 via the wireless transmission unit 19 described later, and the position detection device 3 detects the value of the magnetic field component detected by the magnetic field sensor 16. Based on this, the positional relationship between the target coordinate axis and the reference coordinate axis is derived.

Furthermore, the capsule endoscope 2 includes a transmission circuit 26 and a transmission antenna 27, and includes a wireless transmission unit 19 for performing wireless transmission to the outside, and a plurality of types of signals output to the wireless transmission unit 19. And a switching unit 20 that appropriately switches between the two signals. Specifically, the switching unit 20 is output from the magnetic field signal output via the A / D conversion unit 18, the image signal output via the signal processing unit 15, and the timing control unit 21 (described later). The drive timing signal is appropriately switched and output to the wireless transmission unit 19. Accordingly, these signals are included in the radio signal transmitted via the radio transmission unit 19. As will be described later, in the processing device 12 (described later) provided in the position detection device 3, the capsule endoscope 2 are reconfigured as magnetic field signals S _{1 to} S ₃ , image signal S ₄ and drive timing signal S ₅ , respectively.

  The capsule endoscope 2 includes a speed deriving unit 28 for deriving the moving speed of the capsule endoscope 2 inside the subject 1, and an in-subject information acquiring unit 14 based on a result derived by the speed deriving unit 28. And a timing control unit 21 that controls the drive timing of the magnetic field sensor 16, the wireless transmission unit 19, and the like.

  The speed deriving unit 28 is for deriving the moving speed as an example of the moving state of the capsule endoscope 2. As a specific configuration of the capsule endoscope 2, for example, an acceleration sensor such as a small gyroscope and a mechanism for time-integrating the acceleration detected by the acceleration sensor are provided, and the derived moving speed is set to the timing control unit 21. Has a function of outputting to.

  The timing control unit 21 has a function of controlling at least the drive timing of the magnetic field sensor 16 and the wireless transmission unit 19 among the components of the capsule endoscope 2. Specifically, the timing control unit 21 sets the drive cycle of the magnetic field sensor 16 and the like based on the moving state of the capsule endoscope 2, that is, the moving speed of the capsule endoscope 2 in the first embodiment. The magnetic field sensor 16 and the like are driven at a timing according to the set drive cycle. That is, as the capsule endoscope 2 moves, the in-subject information acquisition unit 14 and the magnetic field sensor 16 have a function of repeatedly performing the in-subject information acquisition operation and the magnetic field detection operation, respectively. Corresponding to the operation, the wireless transmission unit 19 is configured to repeat a predetermined wireless transmission operation. In the first embodiment, the timing control unit 21 is for defining the cycle of the repetitive operation, and the setting of the drive cycle and the like will be described in detail later.

  In addition, the timing control unit 21 has a function of generating a drive timing signal as information related to the drive timing such as the set drive cycle, and the generated drive timing signal is transmitted to the position detection device 3 via the wireless transmission unit 19. Transmitted along with other signals. Further, the timing control unit 21 has a function of controlling the operation content of the switching unit 20, and specifically controls timing for switching a magnetic field signal, an image signal, and a drive timing signal input to the switching unit 20. To do.

  Next, the position detection device 3 will be described. As shown in FIG. 1, the position detection device 3 includes receiving antennas 7a to 7d for receiving a radio signal transmitted from the capsule endoscope 2, and a first linear magnetic field forming unit that forms a first linear magnetic field. 9, a second linear magnetic field forming unit 10 that forms a second linear magnetic field, a diffusion magnetic field forming unit 11 that forms a diffusion magnetic field, a wireless signal received via the receiving antennas 7 a to 7 d, and the like. And a processing device 12 that performs processing.

  The receiving antennas 7a to 7d are for receiving radio signals transmitted from the radio transmitting unit 19 provided in the capsule endoscope 2. Specifically, the receiving antennas 7a to 7d are formed by a loop antenna or the like, and have a function of transmitting a received radio signal to the processing device 12.

  It should be noted that specific configurations of the receiving antennas 7a to 7d and the first linear magnetic field forming unit 9 described below are not limited to those shown in FIG. In other words, FIG. 1 schematically shows only these components, and the number of receiving antennas 7a to 7d and the like is not limited to the number shown in FIG. As for the shape and the like, any configuration can be adopted without being limited to that shown in FIG.

  Next, the first linear magnetic field forming unit 9, the second linear magnetic field forming unit 10, and the diffusion magnetic field forming unit 11 that respectively form the first linear magnetic field, the second linear magnetic field, and the diffusion magnetic field that function as the position detection magnetic field will be described. . The first linear magnetic field forming unit 9 is for forming a linear magnetic field in a predetermined direction in the subject 1. Here, the “linear magnetic field” refers to a magnetic field component substantially only in one direction in at least a predetermined spatial region, in this first embodiment, in a spatial region where the capsule endoscope 2 inside the subject 1 can be located. The magnetic field. Specifically, as shown in FIG. 1, the first linear magnetic field forming unit 9 includes a coil formed so as to cover the body portion of the subject 1 and supplies predetermined power to the coil. It has a function of forming a linear magnetic field in a spatial region inside the subject 1 by flowing predetermined power through a power supply unit (not shown). Here, an arbitrary direction may be selected as the traveling direction of the first linear magnetic field, but in the first embodiment, the first linear magnetic field is z on the reference coordinate axis fixed with respect to the subject 1. It is assumed that the magnetic field is a linear magnetic field traveling in the axial direction.

  FIG. 3 is a schematic diagram showing the first linear magnetic field formed by the first linear magnetic field forming unit 9. As shown in FIG. 3, the coil forming the first linear magnetic field forming unit 9 is formed so as to include the body of the subject 1 inside and has a configuration extending in the z-axis direction on the reference coordinate axis. Therefore, as shown in FIG. 3, the first linear magnetic field formed in the subject 1 by the first linear magnetic field forming unit 9 forms magnetic force lines that travel in the z-axis direction of the reference coordinate axis.

  The second linear magnetic field forming unit 10 is for forming a second linear magnetic field that is a linear magnetic field that travels in a direction different from the first linear magnetic field. Further, the diffusion magnetic field forming unit 11 is different from the first linear magnetic field forming unit 9 and the second linear magnetic field forming unit 10 in that the magnetic field direction has a position dependency, which is the diffusion magnetic field forming unit 11 in the first embodiment. It is for forming the magnetic field which spreads as it separates from.

  FIG. 4 is a schematic diagram showing the configuration of the second linear magnetic field forming unit 10 and the diffusion magnetic field forming unit 11 and the mode of the second linear magnetic field formed by the second linear magnetic field forming unit 10. As shown in FIG. 4, the second linear magnetic field forming unit 10 includes a coil 33 that extends in the y-axis direction of the reference coordinate axis and has a coil cross section that is parallel to the xz plane. For this reason, as shown in FIG. 4, the second linear magnetic field formed by the coil 33 becomes a linear magnetic field at least inside the subject 1 and gradually attenuates as the distance from the coil 33 increases, that is, the strength. Will have a position dependency.

  The diffusion magnetic field forming unit 11 includes a coil 34. Here, the coil 33 is arranged so as to form a magnetic field having a traveling direction in a predetermined direction. In the case of the first embodiment, the traveling direction of the linear magnetic field formed by the coil 33 is the reference coordinate axis. In the y-axis direction. Further, the coil 34 is fixed at a position where a diffusion magnetic field that is the same as the magnetic field direction stored in the magnetic force line direction database 42 described later is formed.

  FIG. 5 is a schematic diagram showing an aspect of the diffusion magnetic field formed by the diffusion magnetic field forming unit 11. As shown in FIG. 5, the coil 34 provided in the diffusion magnetic field forming unit 11 is formed in a spiral shape on the surface of the subject 1, and the diffusion magnetic field formed by the diffusion magnetic field forming unit 11 is shown in FIG. Thus, in the magnetic field formed by the coil 34 (not shown in FIG. 5), the magnetic lines of force are once diffused radially and are incident on the coil 34 again. Further, the diffusion magnetic field forming unit 11 is also arranged outside the subject 1 and forms a magnetic field radially, so that the formed diffusion magnetic field has a characteristic that the intensity decreases as the distance from the coil 34 increases.

Next, the processing device 12 will be described. FIG. 6 is a block diagram schematically showing a specific configuration of the processing device 12. First, the processing device 12 has a function of performing reception processing of a radio signal transmitted by the capsule endoscope 2. Corresponding to such a function, the processing device 12 performs a demodulation process or the like on a reception antenna selection unit 37 that selects any one of the reception antennas 7a to 7d and a radio signal received through the selected reception antenna. Thus, a receiving circuit 38 that extracts an original signal included in a wireless signal and a signal processing unit 39 that reconstructs an image signal or the like by processing the extracted original signal are provided. Specifically, the signal processing unit 39 reconstructs the magnetic field signals S _{1 to} S ₃ , the image signal S _4, and the drive timing signal S ₅ based on the extracted original signal, and outputs them to appropriate components. Has the function of Here, the magnetic field signals S _{1 to} S ₃ are magnetic field signals corresponding to the first linear magnetic field, the second linear magnetic field, and the diffusion magnetic field detected by the magnetic field sensor 16, respectively. The image signal S ₄ corresponds to the in-subject image acquired by the in-subject information acquisition unit 14, and the drive timing signal S ₅ corresponds to the drive timing signal generated by the timing control unit 21. is there. Among these, the image signal S ₄ reconstructed by the signal processing unit 39 is output to the recording unit 43. The recording unit 43 is for outputting input data to the portable recording medium 5, and records not only the image signal S ₄ but also the result of position detection, which will be described later, on the portable recording medium 5. Has the function of

The processing device 12 is fixed to the subject 1 and the function of detecting the position of the capsule endoscope 2 in the subject 1 based on the magnetic field intensity detected by the capsule endoscope 2. A function of detecting an orientation formed by the target coordinate axis fixed with respect to the capsule endoscope 2 with respect to the reference coordinate axis. Specifically, among the signals transmitted by the capsule endoscope 2 and output by the signal processing unit 39, the magnetic field signals S ₁ and S ₂ corresponding to the detected intensities of the first linear magnetic field and the second linear magnetic field are used. Based on the direction deriving unit 40 for deriving the direction formed by the target coordinate axis with respect to the reference coordinate axis, the magnetic field signal S ₃ and the magnetic field signal S ₂ corresponding to the detection intensity of the diffusion magnetic field, and the deriving result of the direction deriving unit 40 A position deriving unit 41 for deriving the position of the endoscope 2, and a magnetic force line direction database 42 that records the correspondence between the traveling direction and position of the magnetic force lines constituting the diffusion magnetic field when the position deriving unit 41 derives the position. Prepare. The azimuth derivation and position derivation by these components will be described in detail later.

  Further, the processing device 12 includes a selection control unit 48 that controls an antenna selection mode by the reception antenna selection unit 37. The selection control unit 48 is most suitable for receiving a radio signal transmitted from the capsule endoscope 2 based on the azimuth and position of the capsule endoscope 2 derived by the orientation deriving unit 40 and the position deriving unit 41, respectively. And a function of selecting the receiving antenna 7. The selection control unit 48, the reception circuit 38, and the reception antennas 7a to 7d constitute a reception unit 44, which functions as an example of reception means in the claims.

Further, the processing device 12 has a function of controlling the driving timing of the first linear magnetic field forming unit 9 and the like based on the driving timing signal extracted by the signal processing unit 39. Specifically, the processing device 12 determines the drive timing of the first linear magnetic field forming unit 9, the second linear magnetic field forming unit 10, and the diffusion magnetic field forming unit 11 based on the drive timing signal S ₅ output from the signal processing unit 39. The magnetic field control part 49 to control is provided. And the processing apparatus 12 is further provided with the electric power supply part 51 which has a function which supplies drive electric power with respect to the above component.

  Next, the operation of the intra-subject introduction system according to the first embodiment will be described. In the first embodiment, the capsule endoscope 2 moves in the subject 1 and intermittently repeats acquisition of in-subject information, magnetic field detection, and wireless transmission thereof. 12 performs a predetermined process on the radio signal transmitted intermittently. In the following, a position detection operation using a magnetic field signal or the like included in each of wireless signals repeatedly transmitted from the capsule endoscope 2 will be described, and then the capsule endoscope 2 side will be described. A drive timing control process of the wireless transmission unit 19 or the like that performs wireless signal transmission will be described.

  First, the position detection operation will be described. In the intra-subject introduction system according to the first embodiment, a positional relationship is derived between a reference coordinate axis fixed with respect to the subject 1 and a target coordinate axis fixed with respect to the capsule endoscope 2. Specifically, after deriving the azimuth of the target coordinate axis with respect to the reference coordinate axis, using the derived azimuth, the position of the origin of the target coordinate axis on the reference coordinate axis, that is, within the capsule type inside the subject 1 The position of the endoscope 2 is derived. Therefore, in the following description, after describing the azimuth derivation mechanism, the position derivation mechanism using the derived azimuth will be described. is there.

  The direction deriving mechanism performed by the direction deriving unit 40 will be described. FIG. 7 is a schematic diagram showing the relationship between the reference coordinate axis and the target coordinate axis when the capsule endoscope 2 is moving in the subject 1. As already described, the capsule endoscope 2 travels along the passage path inside the subject 1 and rotates by a predetermined angle with the traveling direction as an axis. Therefore, the target coordinate axis fixed with respect to the capsule endoscope 2 causes a azimuth shift as shown in FIG. 7 with respect to the reference coordinate axis fixed with respect to the subject 1.

  On the other hand, the first linear magnetic field forming unit 9 and the second linear magnetic field forming unit 10 are each fixed to the subject 1. Therefore, the first and second linear magnetic fields formed by the first linear magnetic field forming unit 9 and the second linear magnetic field forming unit 10 are in a fixed direction with respect to the reference coordinate axis, specifically, the first linear magnetic field is the reference coordinate axis. In the z-axis direction, the second linear magnetic field when the second linear magnetic field forming unit 10 is used proceeds in the y-axis direction.

  Orientation derivation in the first embodiment is performed using the first linear magnetic field and the second linear magnetic field. Specifically, first, the magnetic field sensor 16 provided in the capsule endoscope 2 detects the traveling directions of the first linear magnetic field and the second linear magnetic field supplied in time division. The magnetic field sensor 16 is configured to detect magnetic field components in the X-axis direction, the Y-axis direction, and the Z-axis direction in the target coordinate axis, and information regarding the traveling direction of the detected first and second linear magnetic fields in the target coordinate axis is as follows. And transmitted to the position detection device 3 via the wireless transmission unit 19.

The radio signal transmitted by the capsule endoscope 2 is processed as the magnetic field signals S ₁ and S ₂ through processing by the signal processing unit 39 and the like. For example, in the example of FIG. 7, the magnetic field signal S ₁ includes information regarding coordinates (X ₁ , Y ₁ , Z ₁ ) as the traveling direction of the first linear magnetic field, and the magnetic field signal S ₂ includes the second Information about coordinates (X ₂ , Y ₂ , Z ₂ ) is included as the traveling direction of the linear magnetic field. On the other hand, the orientation deriving unit 40 receives the magnetic field signals S ₁ and S ₂ and derives the orientation of the target coordinate axis with respect to the reference coordinate axis. Specifically, the azimuth deriving unit 40 has coordinates (X ₃ ) at which the inner product value for both (X ₁ , Y ₁ , Z ₁ ) and (X ₂ , Y ₂ , Z ₂ ) is 0 on the target coordinate axis. , Y ₃ , Z ₃ ) as corresponding to the direction of the z axis in the reference coordinate axis. Then, the azimuth deriving unit 40 performs a predetermined coordinate conversion process based on the above correspondence, derives the coordinates on the reference coordinate axes of the X axis, the Y axis, and the Z axis in the target coordinate axis, and uses these coordinates as azimuth information. Output. The above is the direction deriving mechanism by the direction deriving unit 40.

Next, a position derivation mechanism of the capsule endoscope 2 by the position derivation unit 41 using the derived azimuth information will be described. The position deriving unit 41 has a configuration in which magnetic field signals S ₂ and S ₃ are input from the signal processing unit 39, azimuth information is input from the azimuth deriving unit 40, and information stored in the magnetic force line azimuth database 42 is input. . The position deriving unit 41 derives the position of the capsule endoscope 2 as follows based on the input information.

First, the position deriving unit 41 uses the magnetic field signal S _2, performs the derivation of the distance between the second linear magnetic field generator 10 and the capsule endoscope 2. The magnetic field signal S ₂ corresponds to the detection result of the second linear magnetic field in the region where the capsule endoscope 2 exists, and the second linear magnetic field is arranged outside the subject 1 by the second linear magnetic field forming unit 10. Corresponding to this, the strength is attenuated as the distance from the second linear magnetic field forming unit 10 increases. By utilizing such properties, the position deriving unit 41, the intensity of the second linear magnetic field in the second linear magnetic field generator 10 near (determined from the current value to be supplied to the second linear magnetic field generator 10), from the magnetic field signal S ₂ The strength of the second linear magnetic field in the obtained region of the capsule endoscope 2 is compared, and the distance r between the second linear magnetic field forming unit 10 and the capsule endoscope 2 is derived. As a result of deriving the distance r, it is clear that the capsule endoscope 2 is located on the curved surface 52 that is a set of points separated from the second linear magnetic field forming unit 10 by the distance r, as shown in FIG. It becomes.

Then, the position deriving unit 41 derives the position on the curved surface 52 of the capsule endoscope 2 based on the magnetic field signal S ₃ , the direction information derived by the direction deriving unit 40 and the information stored in the magnetic force direction database 42. . Specifically, based on the magnetic field signal S ₃ and orientation information, to derive the traveling direction of the diffusion field at the location of the capsule endoscope 2. Since the magnetic field signal S ₃ is a signal corresponding to the result of detecting the diffusion magnetic field based on the target coordinate axis, the direction of the diffusion magnetic field based on the magnetic field signal S ₃ is coordinated from the target coordinate axis to the reference coordinate axis using the azimuth information. By performing the conversion process, the traveling direction of the diffusion magnetic field on the reference coordinate axis at the position where the capsule endoscope 2 exists is derived. Since the magnetic field direction database 42 records the correspondence between the traveling direction and position of the diffusion magnetic field on the reference coordinate axis, the position deriving unit 41 is stored in the magnetic field direction database 42 as shown in FIG. The position corresponding to the traveling direction of the diffusion magnetic field derived by referring to the information is derived, and the derived position is specified as the position of the capsule endoscope 2. By performing the above processing, the azimuth and position of the capsule endoscope 2 in the subject 1 are derived, and the position detection is completed.

  The above-described position detection operation is repeatedly performed with reception of a wireless signal repeatedly transmitted from the capsule endoscope 2 side. The detected azimuth and position of the capsule endoscope 2 are recorded on the portable recording medium 5 via the recording unit 43, and are used together with the recorded image data for diagnosis by a doctor or the like.

  Next, a drive timing control process for the wireless transmission unit 19 and the like that performs wireless signal transmission performed on the capsule endoscope 2 side will be described. FIG. 10 is a flowchart for explaining a drive timing control process performed by the timing control unit 21 provided in the capsule endoscope 2.

  As shown in FIG. 10, the timing control unit 21 acquires the moving speed of the capsule endoscope 2 derived by the speed deriving unit 28 (step S101), and whether the acquired moving speed is greater than a predetermined threshold value. It is determined whether or not (step S102). If it is larger than the threshold (No at Step S102), the drive cycle is set to a predetermined long cycle (Step S103). On the other hand, when it is smaller than the threshold value (step S102, Yes), the drive cycle is set to a predetermined short cycle shorter than the long cycle (step S104). Thereafter, a drive timing signal including at least information related to the set drive cycle is generated (step S105), and the in-vivo information acquiring unit 14, the magnetic field sensor 16, and the wireless transmitter 19 are driven at the drive timing according to the set drive cycle. Drive (step S106).

  In the first embodiment, the timing of magnetic field formation by the first linear magnetic field forming unit 9, the second linear magnetic field forming unit 10 and the diffusion magnetic field forming unit 11 is synchronized with the drive timing set by the timing control unit 21. It is assumed that the magnetic field control unit 49 controls. That is, the magnetic field control unit 49 derives a drive cycle based on the drive timing signal generated by the timing control unit 21 and reconfigured by the signal processing unit 39, and forms the first linear magnetic field at a timing corresponding to the derived drive cycle. The unit 9, the second linear magnetic field forming unit 10, and the diffusion magnetic field forming unit 11 are controlled to be driven. Specifically, the magnetic field control unit 49 controls the drive timing of the first linear magnetic field forming unit 9 and the like by controlling the supply timing of the drive power held in the power supply unit 51.

  Next, advantages of the in-subject introduction system according to the first embodiment will be described. First, as described above, the in-subject introduction system according to the first embodiment drives the wireless transmission unit 19, the magnetic field sensor 16, and the in-subject information acquisition unit 14 based on the movement state of the capsule endoscope 2. It has a configuration for controlling timing. Therefore, the first embodiment has an advantage that the drive timing of the wireless transmission unit 19 and the like can be optimized with respect to the movement state of the capsule endoscope 2.

  For example, in the first embodiment, control using the moving speed of the capsule endoscope 2 is performed as the moving state. Specifically, the timing control unit 21 sets the drive cycle to a short cycle when the capsule endoscope 2 moves at a high speed, and sets the drive cycle to a long cycle when the capsule endoscope 2 moves at a low speed, Control is performed so that the wireless transmission unit 19 and the like operate at a drive timing corresponding to the set drive cycle. Therefore, when the moving speed of the capsule endoscope 2 is low, the frequency of wireless signal transmission and the like decreases, and there is an advantage that wasteful operations can be reduced in the capsule endoscope 2.

  In general, when the capsule endoscope 2 moves at a low speed, the moving distance of the capsule endoscope 2 per unit time is also small, so that the first linear magnetic field detected by the magnetic field sensor 16 is used. And the like have almost the same direction and intensity in a short cycle, and there is little need to drive the magnetic field sensor 16 and the like in a short cycle. Therefore, in the first embodiment, when the moving speed of the capsule endoscope 2 is low, the drive cycle is set to a long cycle, so that the same magnetic field detection and the information related to the similar magnetic field are included multiple times. Repetitive transmission of radio signals is avoided, and the capsule endoscope 2 is prevented from operating wastefully.

  By adopting such a configuration, it is possible to avoid complication of processing in the entire intra-subject introduction system, and it is possible to reduce power consumption in the capsule endoscope 2. The capsule endoscope 2 normally has a configuration that is driven by finite power supplied by a small primary battery or the like for storing in a capsule, for example. Therefore, there is a limit to the power that can be used by the capsule endoscope 2, and the advantage of avoiding power consumption due to useless operation by adopting the configuration of the first embodiment is remarkable. Become.

  In the flowchart shown in FIG. 10, the magnitude relationship with the predetermined threshold is derived in step S102, and two cycles are set according to the magnitude relationship. However, as long as the drive cycle is determined according to the moving speed. In this case, an arbitrary period setting algorithm may be used. Specifically, a plurality of threshold values may be provided to increase the corresponding drive cycle value, or the drive cycle may be set so that the product of the moving speed and the drive cycle becomes a constant value. In particular, in the case of a configuration in which the product of the moving speed and the driving cycle is set to a substantially constant value, a radio signal is transmitted every time it moves by an approximately equal distance regardless of the moving speed. The power consumption of the capsule endoscope 2 can be reduced while making it possible to effectively detect a change in the position of the mirror 2 and the like.

  Further, the first embodiment has an advantage that the power consumption in the position detection device 3 can be reduced. That is, the magnetic field control unit 49 provided in the processing device 12 constituting the position detection device 3 has a function of controlling the driving state of the first linear magnetic field forming unit 9 and the like based on the driving timing signal. Specifically, the magnetic field control unit 49 performs control based on the drive timing signal generated by the timing control unit 21 included in the capsule endoscope 2, so that the magnetic field sensor 16 performs the first operation only at the timing when the magnetic field sensor 16 performs magnetic field detection. The first linear magnetic field forming unit 9, the second linear magnetic field forming unit 10, and the diffusion magnetic field forming unit 11 can be driven. As described above, the first linear magnetic field forming unit 9 and the like have a function of forming a magnetic field based on the power supplied from the power supply unit 51 provided in the processing apparatus 12. Therefore, the power consumption of the power supply unit 51 is reduced by optimizing the drive timing in accordance with the drive cycle of the magnetic field sensor 16 as compared with the conventional case where the magnetic field is formed over the entire period. It is possible.

(Modification)
Next, a modification of the in-subject introduction system according to the first embodiment will be described. The in-subject introduction system according to the present modification has a configuration in which the vibration state of the capsule endoscope is detected as the movement state of the capsule endoscope, and drive timing control is performed based on the vibration state.

  FIG. 11 is a schematic block diagram showing the configuration of the capsule endoscope 54 constituting the present modification. As shown in FIG. 11, in this modification, a vibration detection unit 55 is newly provided instead of the speed deriving unit, and the timing control unit 56 is configured to control the drive timing based on the detection result of the vibration detection unit 55. Have.

  The vibration detection unit 55 is for detecting the movement state of the capsule endoscope 54 as with the speed deriving unit 28 in the first embodiment, and detects the vibration state of the capsule endoscope 54 as the movement state. Is to do. Specifically, the vibration detection unit 55 includes an acceleration sensor, a cantilever, and the like, and has a function of detecting the vibration state of the capsule endoscope 54. Here, the “vibration state” is a broad concept indicating a state of exercising at an acceleration equal to or higher than a certain threshold value, and is not limited to a single vibration motion or the like.

  The advantages of this modification will be described. In this modification, a vibration state is used as the movement state of the capsule endoscope 54. For example, when the capsule endoscope 54 is stopped inside the subject 1, the timing control unit 56 is used. Can make the drive cycle infinite (that is, temporarily stop the functions of the magnetic field sensor 16 and the like). Therefore, it is possible to prevent the magnetic field sensor 16 and the like from being driven wastefully when stopped (that is, when the position does not change), and as a result, it is possible to reduce power consumption.

  Further, in this modified example, at the time of position detection, the orientation of the capsule endoscope 54 by the orientation deriving unit 40 is derived similarly to the first embodiment, and the capsule endoscope 54 is The azimuth may be changed while staying in a predetermined region (that is, in a state where the value of the moving speed is 0). Since the present modification has a function of controlling the drive timing by detecting vibrations, the capsule endoscope 54 performs a predetermined drive even when the direction of the capsule endoscope 54 is changed while maintaining the state of 0. It is possible to operate at the timing, and even in such a case, there is an advantage that the position detection (particularly, the derivation of the direction) can be reliably performed.

(Embodiment 2)
Next, the in-subject introduction system according to the second embodiment will be described. In the intra-subject introduction system according to the second embodiment, the position detection device side derives the movement state of the capsule endoscope, and wirelessly transmits information regarding the derived movement state to the capsule endoscope Is adopted. In addition, in the following description, what attached | subjected the code | symbol and name similar to Embodiment 1 shall have the structure and function similar to Embodiment 1 unless there is particular mention below.

  FIG. 12 is a schematic diagram illustrating an overall configuration of the intra-subject introduction system according to the second embodiment. As shown in FIG. 12, the in-subject introduction system according to the second embodiment has basically the same configuration as the in-subject introduction system according to the first embodiment, while the position detection device 58 includes The transmission antennas 59a to 59d are newly provided.

  Next, the capsule endoscope 57 constituting the in-subject introduction system according to the second embodiment will be described. FIG. 13 is a block diagram schematically showing the configuration of the capsule endoscope 57. As shown in FIG. As shown in FIG. 13, the capsule endoscope 57 has the same basic configuration as that of the capsule endoscope 2 in the first embodiment, but is newly transmitted from the position detection device 58. The wireless reception unit 61 that performs signal reception processing and a signal processing unit 64 that extracts the moving speed of the capsule endoscope 57 from the signals processed by the wireless reception unit 61 are included.

  The wireless reception unit 61 receives a wireless signal transmitted from the position detection device 58 and performs reception processing for extracting a predetermined original signal by performing demodulation or the like. Specifically, the radio reception unit 61 includes a reception antenna 62 for receiving a radio signal, and a reception circuit 63 that performs reception processing such as demodulation on the radio signal received via the reception antenna 62. Is done.

  The signal processing unit 64 is for reconstructing information included in the radio signal based on the original signal extracted from the radio signal by the radio reception unit 61. In the present second embodiment, as will be described later, the wireless signal transmitted from the position detection device 58 includes information on the moving speed of the capsule endoscope 57, and the signal processing unit 64 It has a function of extracting information related to the moving speed of the endoscope 57 and outputting the information to the timing control unit 21.

  Next, the configuration of the processing device 60 provided in the position detection device 58 will be described. FIG. 14 is a schematic block diagram illustrating the configuration of the processing device 60. As shown in FIG. 14, the processing device 60 basically has the same configuration as the processing device 12 in the first embodiment, while the capsule endoscope 57 of the capsule endoscope 57 is based on the information recorded in the recording unit 43. A moving speed deriving unit 67 for deriving a moving speed, a transmitting circuit 68 for generating a radio signal including information on the moving speed, a transmitting antenna selecting unit 69 for selecting an antenna for transmitting the radio signal generated by the transmitting circuit 68, Is provided.

The moving speed deriving unit 67 is for deriving the moving speed of the capsule endoscope 57 based on the past position detection results regarding the capsule endoscope 57. Specifically, the recording unit 43 has a function of recording the position of the capsule endoscope 57 derived by the position deriving unit 41 with respect to a plurality of times as described in the first embodiment. The moving speed deriving unit 67 acquires the position of the capsule endoscope 57 recorded in the recording unit 43 at a plurality of past times and information on the times at which the positions are derived, thereby obtaining the capsule endoscope 57. The movement speed is derived. Specifically, for example, in the capsule endoscope 57 time _{t 1 (x 1, y 1} , z 1) located in at time t ₂ has elapsed by Δt from time _{t 1 (x 2, y 2} , z ₂ ). Using this information, the moving speed v

v = {(x ₂ −x ₁ ) ² + (y ₂ −y ₁ ) ² + (z ₂ −z ₁ ) ² } ^1/2 / Δt (1)

Can be defined by

  The transmission circuit 68 is for generating a radio signal including information on the moving speed derived by the moving speed deriving unit 67. Specifically, the transmission circuit 68 generates a radio signal by performing necessary processing such as modulation processing.

  The transmission antenna selection unit 69 is for selecting a transmission antenna most suitable for transmitting a radio signal among a plurality of transmission antennas 59a to 59d. Specifically, like the reception antenna selection unit 37, the transmission antenna selection unit 69 has a function of selecting a transmission antenna from the transmission antennas 59 a to 59 d based on the control of the selection control unit 48. The transmission circuit 68, the transmission antenna selection unit 69, and the transmission antennas 59a to 59d constitute a transmission unit 70.

  Next, advantages of the in-subject introduction system according to the second embodiment will be described. The in-subject introduction system according to the second embodiment controls the drive timing of the magnetic field sensor 16 and the like provided in the capsule endoscope 57 according to the moving speed of the capsule endoscope 57 as in the first embodiment. In addition, the magnetic field forming timing of the first linear magnetic field forming unit 9 provided in the position detection device 58 is controlled. Therefore, as in the first embodiment, it is possible to suppress the useless operation of the capsule endoscope 57 and the like, and there are advantages such as reduction in power consumption.

  Further, the second embodiment has a configuration in which the moving speed of the capsule endoscope 57 is performed by the moving speed deriving unit 67 provided in the processing device 60, and there is a new advantage by adopting such a configuration. First, the second embodiment has an advantage that it is not necessary to arrange a speed deriving unit inside the capsule endoscope 57, and the capsule endoscope 57 can be prevented from being enlarged.

(Embodiment 3)
Next, the in-subject introduction system according to the third embodiment will be described. The in-subject introduction system according to the third embodiment has a function of performing position detection by using geomagnetism instead of the first linear magnetic field.

  FIG. 15 is a schematic diagram illustrating an overall configuration of the intra-subject introduction system according to the third embodiment. As shown in FIG. 15, the in-subject introduction system according to the third embodiment includes a capsule endoscope 2, a display device 4, and a portable recording medium 5, as in the first embodiment. The configuration of the device 72 is different. Specifically, the first linear magnetic field forming unit 9 provided in the position detection device in the first embodiment or the like is omitted, and a geomagnetic sensor 73 is newly provided. The processing device 74 also has a configuration different from that of the first embodiment.

  The geomagnetic sensor 73 basically has the same configuration as the magnetic field sensor 16 provided in the capsule endoscope 2. That is, the geomagnetic sensor 73 has a function of detecting the strength of the magnetic field component in the predetermined three-axis direction in the arranged region and outputting an electrical signal corresponding to the detected magnetic field strength. On the other hand, unlike the magnetic field sensor 16, the geomagnetic sensor 73 is disposed on the body surface of the subject 1 and is respectively in the x-axis, y-axis, and z-axis directions on the reference coordinate axis fixed with respect to the subject 1. It has a function of detecting the intensity of the corresponding magnetic field component. That is, the geomagnetic sensor 73 has a function of detecting the traveling direction of the geomagnetism, and outputs an electrical signal corresponding to the magnetic field strength detected in the x-axis direction, the y-axis direction, and the z-axis direction to the processing device 74. Have

  Next, the processing device 74 according to the third embodiment will be described. FIG. 16 is a block diagram illustrating a configuration of the processing device 74. As shown in FIG. 16, the processing device 74 basically has the same configuration as the processing device 12 in the first embodiment, while the geomagnetism on the reference coordinate axis based on the electrical signal input from the geomagnetic sensor 73. And a geomagnetic azimuth deriving unit 75 that outputs the derived result to the azimuth deriving unit 40.

  A problem that arises when geomagnetism is used as the first linear magnetic field is derivation of the advancing direction of geomagnetism on the reference coordinate axis fixed with respect to the subject 1. That is, since the subject 1 can freely move while the capsule endoscope 2 moves in the body, the positional relationship between the reference coordinate axis fixed to the subject 1 and the geomagnetism. Is expected to change as the subject 1 moves. On the other hand, from the viewpoint of deriving the positional relationship of the target coordinate axis with respect to the reference coordinate axis, when the traveling direction of the first linear magnetic field in the reference coordinate axis is unknown, the reference coordinate axis and the target coordinate axis are related to the traveling direction of the first linear magnetic field. The problem will be that the correspondence cannot be clarified.

  Therefore, in the third embodiment, the geomagnetic sensor 73 and the geomagnetic azimuth deriving unit 75 are provided to monitor the advancing direction of the geomagnetism that varies on the reference coordinate axis due to the movement of the subject 1 or the like. That is, based on the detection result of the geomagnetic sensor 73, the geomagnetic azimuth deriving unit 75 derives the geomagnetic traveling direction on the reference coordinate axis and outputs the derived result to the azimuth deriving unit 40. On the other hand, the azimuth deriving unit 40 derives the correspondence between the reference coordinate axis and the target coordinate axis with respect to the direction of geomagnetism by using the input direction of geomagnetism, and combines it with the correspondence in the second linear magnetic field. It is possible to derive azimuth information.

  Depending on the direction of the subject 1, the geomagnetism traveling direction and the second linear magnetic field formed by the second linear magnetic field forming unit 10 may be parallel to each other. In such a case, it is possible to detect the positional relationship by using data on the direction of the target coordinate axis and the position of the origin at the immediately preceding time. Further, in order to avoid that the geomagnetism and the second linear magnetic field are parallel to each other, the extending direction of the coil 34 constituting the second linear magnetic field forming unit 10 is the y-axis direction on the reference coordinate axis as shown in FIG. For example, it is also effective to have a configuration that extends in the z-axis direction.

  Next, advantages of the in-subject introduction system according to the third embodiment will be described. The in-subject introduction system according to the third embodiment has further advantages by using geomagnetism in addition to the advantages in the first embodiment. That is, by adopting a configuration using geomagnetism as the first linear magnetic field, it is possible to omit the mechanism for forming the first linear magnetic field, and the subject at the time of introduction of the capsule endoscope 2 It is possible to derive the positional relationship of the target coordinate axis with respect to the reference coordinate axis while reducing the burden of 1. Since the geomagnetic sensor 73 can be configured using an MI sensor or the like, the geomagnetic sensor 73 can be sufficiently miniaturized, and the burden on the subject 1 does not increase by newly providing the geomagnetic sensor 73. .

  In addition, by adopting a configuration in which geomagnetism is used as the first linear magnetic field, there is an advantage from the viewpoint of reducing power consumption. That is, when the first linear magnetic field is formed using a coil or the like, the power consumption increases due to the current flowing through the coil, but the use of geomagnetism requires such power consumption. Therefore, it is possible to realize a system with low power consumption.

1 is a schematic diagram illustrating an overall configuration of an in-subject introduction system according to a first embodiment. It is a typical block diagram which shows the structure of the capsule endoscope with which an in-subject introduction system is equipped. It is a schematic diagram which shows the 1st linear magnetic field formed by the 1st linear magnetic field formation part with which a position detection apparatus is equipped. It is a schematic diagram which shows the aspect of the 2nd linear magnetic field formed by the 2nd linear magnetic field formation part while showing the structure of the 2nd linear magnetic field formation part with which a position detection apparatus is equipped, and a diffusion magnetic field formation part. It is a schematic diagram which shows the aspect of the diffusion magnetic field formed by the diffusion magnetic field formation part. It is a typical block diagram which shows the structure of the processing apparatus with which a position detection apparatus is equipped. It is a schematic diagram which shows the relationship between a reference | standard coordinate axis and an object coordinate axis. It is a schematic diagram which shows the utilization aspect of a 2nd linear magnetic field in the case of position derivation. It is a schematic diagram which shows the utilization aspect of the diffusion magnetic field in the case of position derivation. It is a flowchart for demonstrating the process in the timing control part with which a capsule endoscope is equipped. FIG. 10 is a schematic block diagram illustrating a configuration of a capsule endoscope in a modification of the first embodiment. FIG. 3 is a schematic diagram illustrating an overall configuration of an in-subject introduction system according to a second embodiment. It is a typical block diagram which shows the structure of the capsule endoscope with which an in-subject introduction system is equipped. It is a typical block diagram which shows the structure of the processing apparatus with which the in-subject introduction system is equipped. FIG. 6 is a schematic diagram illustrating an overall configuration of an in-subject introduction system according to a third embodiment. It is a typical block diagram which shows the structure of the processing apparatus with which the in-subject introduction system is equipped.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Subject 2 Capsule endoscope 3 Position detection apparatus 4 Display apparatus 5 Portable recording medium 7a-7d Reception antenna 9 1st linear magnetic field formation part 10 2nd linear magnetic field formation part 11 Diffusion magnetic field formation part 12 Processing apparatus 14 Subject In-specimen information acquisition unit 15 Signal processing unit 16 Magnetic field sensor 17 Amplification unit 18 A / D conversion unit 19 Wireless transmission unit 20 Switching unit 21 Timing control unit 22 LED
23 LED drive circuit 24 CCD
Reference Signs List 25 CCD drive circuit 26 transmitting circuit 27 transmitting antenna 28 speed deriving unit 33 coil 34 coil 37 receiving antenna selecting unit 38 receiving circuit 39 signal processing unit 40 direction deriving unit 41 position deriving unit 42 magnetic field direction database 43 recording unit 48 selection control unit 49 Magnetic field control unit 51 Power supply unit 52 Curved surface 54 Capsule type endoscope 55 Vibration detection unit 56 Timing control unit 57 Capsule type endoscope 58 Position detection device 59a to 59d Transmission antenna 60 Processing device 61 Wireless reception unit 62 Reception antenna 63 Reception Circuit 64 Signal processing unit 67 Moving speed deriving unit 68 Transmitting circuit 69 Transmitting antenna selecting unit 70 Wireless transmitting unit 72 Position detecting device 73 Geomagnetic sensor 74 Processing device 75 Geomagnetic direction deriving unit

Claims (7)

An in-subject introduction device that is introduced into the subject and moves within the subject, and a position detection device that detects the position of the in-subject introduction device within the subject using a predetermined magnetic field for position detection An in-subject introduction system comprising:
The in-subject introduction device comprises:
A magnetic field sensor for detecting the position detection magnetic field in a region where the intra-subject introduction apparatus is located;
Wireless transmission means for transmitting a wireless signal including a detection result by the magnetic field sensor;
Timing control means for controlling the drive timing of the wireless transmission means and / or the magnetic field sensor based on the movement state of the in-subject introduction apparatus inside the subject;
With
The position detection device includes:
Magnetic field forming means for forming the position detecting magnetic field;
Receiving means for receiving a wireless signal including a detection result by the magnetic field sensor;
Position deriving means for deriving the position of the in-subject introduction device in the subject based on the radio signal subjected to the reception processing by the receiving means;
An in-subject introduction system characterized by comprising: The in-subject introduction apparatus further includes speed deriving means for deriving a movement speed of the in-subject introduction apparatus as the movement state,
The in-subject introduction system according to claim 1, wherein the timing control unit controls the driving timing based on a moving speed derived by the speed deriving unit.   The timing control unit sets a driving cycle of the wireless transmission unit and / or the magnetic field sensor to a predetermined long cycle when the moving speed is low, and sets the driving cycle to the long cycle when the moving speed is high. The in-subject introduction system according to claim 1 or 2, wherein a short cycle that is shorter than the cycle is set. The in-subject introduction device further includes vibration detection means for detecting a vibration state of the in-subject introduction device as the movement state,
The in-subject introduction system according to claim 1, wherein the timing control unit controls the drive timing based on a vibration state detected by the vibration detection unit. The wireless signal transmitted by the wireless transmission means further includes information on the drive timing,
The said position detection apparatus is further equipped with the magnetic field control means which controls the magnetic field formation timing by the said magnetic field formation means based on the information regarding the said drive timing contained in the said radio | wireless signal. The intra-subject introduction system according to one. The position detection device includes:
A moving speed deriving means for deriving a moving speed of the intra-subject introduction apparatus based on the positions of the intra-subject introduction apparatus at a plurality of times derived by the position deriving means;
Transmitting means for transmitting a radio signal including the moving speed derived by the moving speed deriving means as information;
Further comprising
The in-subject introduction device comprises:
Wireless reception means for performing reception processing of the wireless signal transmitted by the transmission means;
A moving speed deriving unit for deriving a moving speed of the intra-subject introduction apparatus based on the radio signal received and processed by the wireless receiving unit, and outputting information on the derived moving speed to the timing control unit;
The in-subject introduction system according to claim 1, further comprising:   The subject according to claim 6, wherein the position detecting device further includes a magnetic field control unit that controls a magnetic field formation timing by the magnetic field forming unit based on a moving speed derived by the speed deriving unit. Internal introduction system.

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