JP2008029864A - Capsule medical apparatus direction/position detecting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capsule medical apparatus direction/position detecting device system capable of stably detecting the direction and position of a capsule medical apparatus body. <P>SOLUTION: The capsule medical apparatus direction/position detecting device system comprises a coil 42 mounted in a capsule body 3; magnetic field generating means (excitation coil arrays 51a and 51b) for generating a magnetic field for generating induced electromotive force in the coil 42; magnetic field detecting means (detection coil arrays 52a and 52b) composed of at least one set of opposed coils for detecting the field intensity from the coil; and a computing means (an arithmetic operation part 54) for computing the direction and position of the capsule body based on the detection value received from the magnetic field detecting means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a capsule medical device direction position detection system for detecting the position and direction of a capsule medical device body inserted into a body cavity.

  For example, Japanese Patent Laid-Open No. 2001-179700 discloses a conventional example in which the inside of a subject is propelled by a rotating magnetic field. In the above Japanese Patent Laid-Open No. 2001-179700, a magnetic field generator that generates a rotating magnetic field, a robot body that receives the rotating magnetic field and rotates to obtain thrust, a position detector that detects the position of the robot body, Movement control of a movable micromachine having magnetic field changing means for changing the direction of the rotating magnetic field by the magnetic field generation unit to direct the robot main body in a direction to reach the destination based on the position of the robot main body detected by the position detection unit A system is disclosed.

  The movement control system for a micromachine described in the above-mentioned Japanese Patent Application Laid-Open No. 2001-179700, when moving inside a liquid that is a gel-like substance, shows the next movement direction based on position information. The direction can be changed relatively freely. Therefore, the micromachine movement control system described in Japanese Patent Laid-Open No. 2001-179700 does not utilize direction (direction) information for control.

Japanese Patent Application Laid-Open No. 2001-179700 discloses a system for detecting the position of a micromachine. The system detects a magnetic field of a magnet of a micromachine, and has a magnetic field generating means outside, and is a capsule type medical device. There is no disclosure of a system in which a coil provided in the apparatus receives a magnetic field generated by a magnetic field generating means to generate an induced magnetic field, and detects the position by detecting the induced magnetic field generated by the coil.
JP 2001-179700 A

  However, the movement control system of the micromachine described in the above-mentioned Japanese Patent Application Laid-Open No. 2001-179700 is such that the lumen width and diameter are reduced, narrowed, or the lumen meanders like a body lumen. In some cases, the micromachine cannot be guided smoothly.

  Therefore, when the micromachine movement control system described in JP-A-2001-179700 is applied to guide control of a capsule medical device moving in a body cavity, the capsule medical device suppresses a change in direction by a lumen. It is not always possible to proceed or change direction in the specified direction. Therefore, if the magnetic field in the target direction is generated without considering the above, there is a possibility that the capsule medical device may not be able to operate due to the suppression of the lumen. In order to solve the above problem, it is necessary to perform control in consideration of the direction of the capsule medical device. In order to detect the orientation of the capsule medical device, it is necessary to stably and strongly generate the induced electromotive force generated in the coil.

  The present invention has been made in view of the above-described points, and an object of the present invention is to provide a capsule medical device direction position detection system that can stably detect the direction and position of the capsule medical device body.

A capsule medical device direction position detection system according to an aspect of the present invention includes a direction detection unit that detects a direction of a capsule medical device body, and the direction detection unit includes:
A coil provided in the capsule medical device body;
Magnetic field generating means for generating an alternating magnetic field for generating an induced electromotive force in the coil provided in the capsule medical device body;
Magnetic field detection means for detecting magnetic field intensity from the coil provided in the capsule medical device body;
Receiving a detection value from the magnetic field detection means, and calculating means for calculating the orientation and position of the capsule medical device body,
The magnetic field generating means is composed of at least one pair of opposed coils.

  The capsule medical device direction position detection device system of the present invention has an effect that the direction and position of the capsule medical device body can be stabilized.

  An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 11 relate to an embodiment of the present invention, FIG. 1 is an overall configuration diagram of a capsule medical device magnetic guidance system of the embodiment, and FIG. 2 is a circuit block of the capsule medical device magnetic guidance system of FIG. FIG. 3, FIG. 3 is a side view of the capsule body, FIG. 4 is a view illustrating how the rotating magnetic field changes when a rotating magnetic field is applied, and FIG. 6 is an explanatory diagram showing a rotating magnetic field generator and a direction / position detecting device, FIG. 7 is an enlarged perspective view of the rotating magnetic field generating device and the direction / position detecting device of FIG. 6, and FIG. 8 is a rotating magnetic field generating device of FIG. FIG. 9 is a perspective view of a rotating magnetic field generator and a direction / position detecting device showing a modification of the direction / position detecting device of FIG. 7, and FIG. 10 is a rotating magnetic field generator of FIG. Cutting device and direction / position detection device 11 is a flowchart showing an operation of controlling the direction of the rotating magnetic field based on the direction (direction) and position information of the capsule body detected by the direction / position detection device, and FIG. 12 is a direction / position detection device of FIG. FIG. 13 is a flowchart showing an operation for controlling the direction of the rotating magnetic field and the like based on the orientation (direction) and position information of the capsule body detected by the direction / position detection device of FIG. FIG. 14 is a flowchart showing the control further added to the flowchart of FIG. 11 or FIG. 13, FIG. 15 is an explanatory view of the capsule body showing a modification of the coil constituting the resonance circuit, and FIG. FIG. 15B is an explanatory view showing a cross-sectional shape of the covering member in FIG. 15A, and FIG. FIG. 16 is a side view of the capsule body in which a coil is wound around a rod-shaped member, and FIG. 16 is a circuit block diagram showing a power supply circuit configured using a resonance circuit composed of the coil of FIG. Is a circuit block diagram showing a first power supply circuit, FIG. 16B is a circuit block diagram showing a second power supply circuit, and FIG. 16C is a circuit block diagram showing a third power supply circuit. .

As shown in FIGS. 1 and 2, the capsule medical device magnetic guidance system 1 according to the first embodiment of the present invention is inserted into a body cavity of a patient (not shown) and functions as a capsule endoscope that images the inside of the body cavity. A capsule type medical device main body 3 (hereinafter abbreviated as a capsule main body), a rotating magnetic field generating device 4 as a first magnetic field generating means that is arranged around the patient, that is, outside the body, and applies a rotating magnetic field to the capsule main body 3. The magnetic field control device (or power supply control device) 5 that controls the supply of a drive current that generates a rotating magnetic field in the rotating magnetic field generating device 4 and the process of performing wireless communication with the capsule body 3 are arranged outside the patient's body. At the same time, the processing device 6 that controls the magnetic field control device 5 to control the direction and magnitude of the rotating magnetic field applied to the capsule body 3 and the processing device 6 are connected to the capsule body 3. For example, an operation input device 8 is connected to the display device 7 for displaying a captured image and the like and the processing device 6 and is operated by an operator such as an operator to input an instruction signal corresponding to the operation. Direction input device 8a for generating a magnetic field direction instruction signal, speed input device 8b for generating a rotating magnetic field instruction signal at a rotation frequency corresponding to the operation, generation of an eccentric rotating magnetic field corresponding to the operation, etc. And a function button 8c for generating an instruction signal corresponding to the function.

  Further, the capsule medical device magnetic induction system 1 generates an alternating magnetic field for generating an induced electromotive force in a resonance circuit 40 (described later) incorporated in the capsule body 3 and generates an induced electromotive force by the alternating magnetic field. A direction detecting means 9 for detecting the magnetic field generated by the resonant circuit 40 and detecting the direction (direction) of the capsule body 3 in the longitudinal direction and detecting the position, and a direction / position detecting device 9 as the direction and position detecting means are provided. ing. The detailed configuration of the direction / position detection device 9 will be described later.

  First, the capsule body 3 will be described.

    As shown in FIG. 3, the capsule main body 3 is provided with a spiral projection (or screw portion) 12 serving as a thrust generating structure portion that generates thrust by rotation on the outer peripheral surface of a capsule-shaped outer container 11. In addition to the inside sealed by the exterior container 11, in addition to the objective optical system 13, the imaging element 14 disposed at the imaging position thereof, and the illumination element 15 (see FIG. 1) that illuminates for imaging. The magnet 16 is accommodated.

  The objective optical system 13 is disposed, for example, inside the hemispherically transparent tip cover 11a in the outer container 11 so that its optical axis coincides with the central axis C of the cylindrical capsule body 3. The central portion of the tip cover 11a becomes the observation window 17. Although not shown in FIG. 3, the illumination element 15 is disposed around the objective optical system 13.

    Therefore, in this case, the visual field direction of the objective optical system 13 is the optical axis direction of the objective optical system 13, that is, the direction along the cylindrical central axis C of the capsule body 3.

    Further, in the capsule body 3, for example, in the vicinity of the rear end of the outer container 11, the capsule coil 42 constituting the resonance circuit 40 is wound in a predetermined direction, specifically, the capsule coil 42 is wound in a solenoid shape. The solenoid is stored in a state where the direction of the capsule body 3 is set in the longitudinal direction.

  Further, the magnet 16 disposed near the center in the longitudinal direction in the capsule body 3 has an N pole and an S pole disposed in a direction orthogonal to the central axis C. In this case, the center of the magnet 16 is arranged so as to coincide with the center of gravity of the capsule body 3, and the center of the magnetic force acting on the magnet 16 when a magnetic field is applied from the outside is the center of gravity of the capsule body 3. Thus, the capsule body 3 can be easily magnetically propelled smoothly. Further, the magnet 16 is arranged so as to coincide with a specific arrangement direction of the image sensor 14. That is, the upward direction when the image captured by the image sensor 14 is displayed is set to the direction from the south pole to the north pole of the magnet 16.

  The rotating magnetic field generator 4 applies a rotating magnetic field to the capsule body 3 to magnetically rotate the magnet 16, and the capsule body 3 with the magnet 16 fixed inside is rotated together with the magnet 16. The spiral protrusion 12 provided on the outer peripheral surface of the main body 3 is rotated in contact with the inner wall of the body cavity so that the capsule main body 3 can be propelled.

  In addition, in this way, when the capsule body 3 including the magnet 16 is controlled by an external magnetic field, it is determined which direction is the upward direction of the image captured by the capsule body 3 from the direction of the external magnetic field. I want to know.

  In the capsule body 3, in addition to the objective optical system 13, the image sensor 14, and the magnet 16 described above, as shown in FIG. 2, a signal processing circuit 20 that performs signal processing on a signal imaged by the image sensor 14, and a signal A memory 21 that temporarily stores a digital video signal generated by the processing circuit 20, and a video signal read from the memory 21 is modulated with a high-frequency signal and converted into a signal to be transmitted wirelessly, or a control signal transmitted from the processing device 6 A radio circuit 22 for demodulating the signal, a capsule control circuit 23 for controlling the capsule body 3 such as the signal processing circuit 20, and a battery 24 for supplying power for operation to the electric system inside the capsule body 3 such as the signal processing circuit 20. It is stored.

  Further, in the capsule body 3, a capacitor 41 that is electrically connected to the in-capsule coil 42 is provided, and constitutes a resonance circuit 40 together with the in-capsule coil 42. In the resonance circuit 40, when an alternating magnetic field is generated by the direction / position detecting device 9, an induced electromotive force is generated by the alternating magnetic field and a current flows.

  The coil 42 has a unique self-resonant frequency. When an alternating magnetic field close to the self-resonant frequency is generated from the direction / position detecting device 9, an effective induced electromotive force can be generated without the capacitor 41. The capacitor 41 can be generated. By doing so, the capacitor 41 can be omitted, the size can be reduced, and the configuration can be simplified.

  The processing device 6 that performs wireless communication with the capsule body 3 includes a wireless circuit 25 that performs wireless communication with the wireless circuit 22, an image display for image data transmitted from the capsule body 3, and the like. Of the rotating magnetic field generated by the rotating magnetic field generator 4 via the power control device 5 and the data processing circuit 26 for performing the data processing, the control circuit 27 for controlling the data processing circuit 26, the power control device 5 and the like. It has a storage circuit 28 for storing state information and setting information by the direction input device 8a or the like.

  A display device 7 is connected to the data processing circuit 26, and an image or the like captured by the image sensor 14 and processed by the data processing circuit 26 via the wireless circuits 22 and 25 is displayed. In addition, since the data processing circuit 26 captures an image while the capsule body 3 is rotated, the data processing circuit 26 performs a process of correcting the orientation of the image when displayed on the display device 7 in a certain direction so that the operator can easily view the image. Image processing is performed so that it can be displayed (described in Japanese Patent Application No. 2002-105493).

    An instruction signal corresponding to the operation is input to the control circuit 27 from the direction input device 8a, the speed input device 8b, and the like constituting the operation input device 8, and the control circuit 27 performs a control operation corresponding to the instruction signal.

  In addition, the control circuit 27 is connected to the storage circuit 28, and the direction of the rotating magnetic field generated by the rotating magnetic field generator 4 via the magnetic field controller 5 (the normal direction of the magnetic field rotation plane of the rotating magnetic field) and the magnetic field The direction information is always stored. After that, even when an operation for changing the direction of the rotating magnetic field or the direction of the magnetic field is performed, the direction of the rotating magnetic field or the direction of the magnetic field is continuously changed so that the rotating magnetic field can be smoothly changed. Yes. Note that the storage circuit 28 may be provided inside the control circuit 27.

  The magnetic field control device 5 connected to the control circuit 27 generates an alternating current, and also includes an alternating current generation and control unit 31 including three alternating current generation and control circuits that control the frequency and phase thereof, A driver unit 32 including three drivers each amplifying an alternating current, and the output currents of the three drivers are supplied to the three electromagnets 33a, 33b, and 33c constituting the rotating magnetic field generator 4, respectively. .

    In this case, the electromagnets 33a, 33b, and 33c are arranged so as to generate magnetic fields in three orthogonal axes. For example, the electromagnets 33a, 33b, and 33c are a pair of opposed coils each having two coils, and a three-axis opposed coil in which the respective magnetic field generation directions are orthogonal can be considered. As an example of the counter coil, two Helmholtz coils arranged so as to sandwich the patient can be considered.

Then, by operating the direction input device 8a constituting the operation input device 8, a magnetic field direction instruction signal is generated, or by operating the speed input device 8b, a rotating magnetic field instruction signal having a rotation frequency corresponding to the operation. Or by generating an oscillating magnetic field (alternating current or periodic) set by operating the function button 8c, the longitudinal axis of the capsule body 3 with respect to the magnet 16 of the capsule body 3 A couple that rotates the central axis C itself around the center point of C can be generated. In this case, the capsule main body 3 is tilted or vibrated because it is applied alternately or periodically so as to change the direction of the oscillating magnetic field (acting as a couple) in the reverse direction before the central axis C itself is completely rotated. It becomes like this. In the direction input device 8a, a rotating magnetic field is generated so as to move the capsule body 3 in the desired direction by tilting in a desired direction to move a joystick (not shown).

  For example, FIG. 4 shows a state when a rotating magnetic field is applied. A rotating magnetic field in which the direction of the rotating magnetic field pole changes on a rotating magnetic field plane perpendicular to the direction of the central axis C in the longitudinal direction of the capsule body 3 is applied. The capsule body 3 is rotated around the longitudinal direction together with the magnet 16 fixed in the capsule body 3 in a direction perpendicular to the longitudinal direction, and the body cavity is formed by the spiral projection 12 shown in FIG. 3 according to the rotational direction. It can be moved forward or backward by engaging with the inner wall. Here, the direction of the rotating magnetic field is defined as the normal direction of the magnetic field rotation plane of the rotating magnetic field.

  Further, in the present embodiment, an oscillating magnetic field (couple generating magnetic field) that acts to oscillate (vibrate) the magnet 16 around the direction y ′ of the central axis C in the longitudinal direction can be applied to the capsule body 3. ing.

  As a result, the capsule body 3 is rotated around the central axis C in the longitudinal direction and is eccentric so that the direction of the central axis C of the rotation is inclined. In other words, the rotational torque of the spinning top is reduced, and an operation in which the mandrel is shaken by the action of gravity (hereinafter, this operation is called a jiggling operation) can be performed.

  In this way, when the capsule body 3 is advanced or retracted along the longitudinal direction of the lumen in a lumen approximately the same as the diameter of the capsule body 3, the capsule body 3 is moved in the longitudinal direction. Can be moved smoothly by applying a rotating magnetic field that rotates around.

  On the other hand, when the capsule body 3 hits the bent portion at a portion where the lumen is bent, and it is simply rotated around the longitudinal direction, it may be difficult to move smoothly in the bending direction. . In such a case, as described above, the oscillating magnetic field is applied along the central axis C in the longitudinal direction of the capsule body 3 so that a force that rotates the central axis C acts on the center. Thus, the capsule body 3 is caused to perform a jiggling operation, and when the longitudinal direction in the jiggling operation is in the bending direction of the lumen, the capsule body 3 can be smoothly moved in that direction. .

  In addition, by tilting the joystick, the state of the capsule body 3 or the state of the rotating magnetic field is always grasped so that the direction of the rotating magnetic field can be controlled from the current traveling direction to a desired arbitrary direction. In this embodiment, the state of the rotating magnetic field (specifically, the direction of the rotating magnetic field and the direction of the magnetic field) is always stored in the storage circuit 28.

  Specifically, an operation instruction signal in the operation input device 8 in FIG. 2 is input to the control circuit 27, and the control circuit 27 outputs a control signal for generating a rotating magnetic field corresponding to the instruction signal to the magnetic field control device 5. The information on the direction of the rotating magnetic field and the direction of the magnetic field is stored in the storage circuit 28.

    Therefore, the storage circuit 28 always stores information on the rotating magnetic field generated by the rotating magnetic field generator 4 and the direction of the periodically changing magnetic field forming the rotating magnetic field.

  The storage circuit 28 is not limited to storing information corresponding to the control signal of the direction of the rotating magnetic field and the direction of the magnetic field from the control circuit 27, and is output from the control circuit 27 to the magnetic field control device 5. Information for determining the direction of the rotating magnetic field and the direction of the magnetic field that are actually output to the rotating magnetic field generating device 4 through the alternating current generating & controlling unit 31 and the driver unit 32 in the magnetic field controlling device 5 according to the control signal. It may be sent from the side to the control circuit 27 and stored in the storage circuit 28.

  In this embodiment, when the application of the rotating magnetic field is started and stopped, or when the direction of the rotating magnetic field (in other words, the direction of the capsule traveling direction) is changed, a sudden force acts on the capsule body 3. The rotating magnetic field is controlled so as to continuously change so as to operate smoothly.

  Further, in the present embodiment, the image picked up by the image pickup device 14 is also rotated by the rotation of the capsule body 3. Therefore, when this is displayed on the display device 7 as it is, the displayed image is also a rotated image. Therefore, since the operability of the instruction operation to the desired direction by the direction input device 8b is lowered, it is desirable to stop the rotation of the display image.

    Therefore, in this embodiment, as described in Japanese Patent Application No. 2002-105493, the data processing circuit 26 and the control circuit 27 perform the process of correcting the rotated image into an image whose rotation is stationary.

    Note that, based on the magnetic field orientation information, the image may be rotated and the capsule body 3 may be canceled and displayed (the image correlation processing or the like may be performed to obtain a still image of a predetermined orientation). Display it).

  Further, as shown in FIG. 5, the direction / position detecting device 9 includes an exciting coil array as second magnetic field generating means for generating an alternating magnetic field for generating an induced electromotive force in the resonance circuit 40 of the capsule body 3. 51, and a detection coil array 52 that detects the magnetic field generated by the resonance circuit 40 of the capsule body 3 to detect the direction (direction) of the capsule body 3 in the longitudinal direction and also detects the position. Yes.

  The excitation coil array 51 and the detection coil array 52 are configured as one set, and in this embodiment, three sets are arranged so as to generate magnetic fields in three orthogonal directions. Further, the direction / position detecting device 9 is configured to measure the signal detected by the detection coil array 52 and the longitudinal direction of the capsule body 3 based on the data measured by the signal measuring device 53. An arithmetic processing unit 54 that calculates a direction (direction) and a position, and the excitation coil array for generating an AC magnetic field necessary for mutual induction of the resonance circuit 40 by the control of the arithmetic processing unit 54. And an oscillator 55 that oscillates 51 at a predetermined oscillation frequency, for example, 1 kHz to 1 MHz.

である。 Here, the measurement magnetic field B _total (vector) detected by the detection coil array 52 is the applied magnetic field generated by the excitation coil array 51 as B _ext (vector), and the magnetic field generated by the resonance circuit 40 is B _reso (vector). As
[Formula 1]

It is.

  The magnetic field generated by the resonance circuit 40 can be described as a function of the position and direction of the resonance circuit 40 on the three-dimensional coordinates (not shown) as follows.

但し、
ｘ_０：カプセル本体３のｘ座標，ｙ_０：カプセル本体３のｙ座標，
ｚ_０：カプセル本体３のｚ座標，
θ：カプセル本体３のｚ軸の回りの角度、φ：カプセル本体３のｙ軸の回りの角度，
ｒ：共振回路４０から検出コイルアレイ５２までの距離，
Ｍ：共振回路４０が生成する等価的な磁気モーメントの強さ
即ち、演算処理部５４は、検出コイルアレイ５２により検出される測定磁界Ｂ_totalから励磁コイルアレイ５１により発生する印加磁界Ｂ_extを減算して共振回路４０により発生する磁界Ｂ_resoを求め、この値からカプセル本体３の位置（ｘ，ｙ，ｚ）、カプセル本体３の向き（θ，φ）及び等価的磁気モーメントＭを算出するようになっている。 [Formula 2]

However,
x ₀ : x coordinate of the capsule body 3, y ₀ : y coordinate of the capsule body 3,
z ₀ : z coordinate of the capsule body 3,
θ: angle around the z-axis of the capsule body 3, φ: angle around the y-axis of the capsule body 3,
r: distance from the resonance circuit 40 to the detection coil array 52,
M: Strength of equivalent magnetic moment generated by the resonance circuit 40 That is, the arithmetic processing unit 54 subtracts the applied magnetic field B _ext generated by the exciting coil array 51 from the measured magnetic field B _total detected by the detection coil array 52. _Thus , the magnetic field B _reso generated by the resonance circuit 40 is obtained, and from this value, the position (x, y, z) of the capsule body 3, the orientation (θ, φ) of the capsule body 3, and the equivalent magnetic moment M are calculated. It has become.

  The excitation coil array 51 and the detection coil array 52 are configured to be incorporated in the rotating magnetic field generator 4 as shown in FIGS. 6 to 8, for example.

    As shown in FIGS. 6 to 8, the excitation coil arrays 51a and 51b and the detection coil arrays 52a and 52b are, for example, on four surfaces excluding the head and feet so that the patient's body can be inserted. The plurality of sense coils 61 are uniformly arranged and face each other.

  The excitation coil arrays 51a and 51b and the detection coil arrays 52a and 52b can be combined such that, for example, if one surface on the front side is an excitation side, one surface on the opposite side is the detection side. As described above, one set is configured, and three sets are arranged so as to generate magnetic fields in three orthogonal directions. In addition, since the detection coil array 52 cannot be arranged as one set for the head and foot portions, the sense coil 63 that is 90 degrees different from the direction (direction) of the sense coil 61 is distributed to the other four surfaces. Forming.

  Further, in order to stably and strongly generate the induced electromotive force in the resonance circuit 40 instead of the excitation coil arrays 51a and 51b, three sets of exciting counter coils (in the form of a cube similar to the rotating magnetic field generator 4) ( Helmholtz coils) 62a, 62b, and 62c may be three-axis Helmholtz coils in which the magnetic field generation directions are orthogonal to each other. Thereby, the induced electromotive force can be stably generated in the resonance circuit 40, and the magnetic field of the resonance circuit 40 can be detected by the detection coil arrays 52a and 52b.

  The excitation coil array 51 and the detection coil array 52 are arranged in a mountain shape at a predetermined angle so as to generate magnetic fields in three orthogonal directions as shown in FIGS. 9 and 10 (51b). (52b) and 51c (52c)). Similarly, two pairs of exciting opposing coils (Helmholtz coils) 62 may be formed in a mountain shape (62b, 62c) at a predetermined angle.

  The thus configured direction / position detecting device 9 inputs the orientation (direction) and position information of the capsule body 3 calculated by the arithmetic processing unit 54 to the control circuit 27 of the processing device 6. Yes.

  When the operation input device 8 is operated, the control circuit 27 generates a rotating magnetic field according to the flowchart described later, based on the information stored in the storage circuit 28 and the information detected by the direction / position detection device 9. Or the direction of the rotating magnetic field generated is controlled.

  The operation of the present embodiment having such a configuration will be described.

    In this embodiment, the rotating magnetic field is generated by the three sets of opposing coils (Helmholtz coils) 33a to 33c of the rotating magnetic field generator 4, and the alternating magnetic field for generating the induced electromotive force in the capsule coil 42 is shown. Is applied to the exciting coil arrays 51a to 51c (not the explanation using the exciting opposing coils (Helmholtz coils) 62a to 62c), and the magnetic field generated by the current caused by the induced electromotive force of the intra-capsule coil 42 is generated. The detection coil arrays 52a to 52c are detected.

  When examining the inside of a body cavity with the capsule body 3, the patient swallows the capsule body 3. When the capsule body 3 inserted into the body cavity passes through the esophagus or the like, it is illuminated by the illumination element 15, and an image captured by the imaging element 14 is wirelessly transmitted to the processing apparatus 6 outside the body via the wireless circuit 22.

  The processing device 6 receives the image data demodulated by the wireless circuit 25 and stores the demodulated image data in an image storage device (such as a hard disk) provided inside the data processing circuit 26 and performs display processing. The images output and sequentially captured by the capsule body 3 are displayed.

  Here, in this embodiment, the control circuit 27 generates or generates a rotating magnetic field based on the direction (direction) and position information of the capsule body 3 detected by the direction / position detection device 9 according to the flowchart shown in FIG. An operation for controlling the direction of the rotating magnetic field is performed.

  First, the control circuit 27 controls and drives the direction / position detection device 9 to measure the direction (direction) and position of the capsule body 3 (step S1).

    The direction / position detection device 9 causes the exciting coil array 51 to oscillate at a predetermined oscillation frequency, for example, 1 kHz to 1 MHz, by an oscillator 55 to generate an alternating magnetic field.

  Then, the resonance circuit 40 of the capsule body 3 generates an induced electromotive force by mutual induction by an AC magnetic field, and generates a magnetic field by causing a current to flow through the coil 42 in the capsule. The magnetic field generated by the resonance circuit 40 is detected by the detection coil array 52. The measurement value detected by the detection coil array 52 is captured by the signal measuring device 53 and input to the arithmetic processing unit 54.

  The arithmetic processing unit 54 calculates the direction (direction) and position of the resonance circuit 40 from the above-described formulas 1 and 2 based on the input measurement value, and the calculated result is the direction (direction) and position of the capsule body 3. The data is output to the control circuit 27 as data.

  The control circuit 27 controls and drives the rotating magnetic field generating device 4 based on the direction (direction) and position data of the capsule body 3 input from the direction / position detecting device 9 to generate the rotating magnetic field. Is set (set) (step S2).

  The control circuit 27 then rotates the magnetic field generator 4 so as to control the capsule body 3 to a desired direction (direction) and position in accordance with an operation input device 8 operated by the operator, for example, a joystick of the direction input device 8a. Control drive.

  That is, the control circuit 27 detects the input of the operation input device 8 (joystick) (step S3), and determines that there is an input (step S4), the capsule main body 3 is operated according to the operation of the operation input device 8. Next, the generation condition of the next rotating magnetic field generated by the rotating magnetic field generation device 4 is calculated so as to control to the desired direction (direction) and position (step S5), and the rotating magnetic field is generated (added) (step S6). When there is no input from the operation input device 8 (joystick), the control circuit 27 maintains the set direction of the rotating magnetic field until this input is present.

  And the capsule main body 3 changes direction (direction) and position according to the produced | generated rotating magnetic field. Here, the capsule main body 3 is easy to face due to excessive movement or difficulty in movement with respect to the operation of the operation input device 8 depending on the state of the lumen, for example, the presence of body fluid or sputum or the size of the organ. The degree of thickness changes, and an error that does not correspond to the calculated orientation of the capsule body 3 occurs.

  Therefore, the control circuit 27 again measures the direction (direction) and position of the capsule body 3, and performs the following control to correct the error.

    That is, the control circuit 27 controls and drives the direction / position detection device 9 again to measure the direction (direction) and position data of the capsule body 3 (step S7).

  The control circuit 27 then obtains the direction (direction) data of the capsule body 3 obtained from the direction / position detection device 9 and the direction of the rotating magnetic field generated by the rotating magnetic field generator 4 (the normal of the magnetic field rotation plane of the rotating magnetic field). (Direction) data is compared (step S8), and it is determined whether or not the comparison result is larger than a preset set value α (step S9).

  Then, the control circuit 27 compares the direction (direction) data of the capsule body 3 obtained from the direction / position detection device 9 with the direction data of the rotating magnetic field generated by the rotating magnetic field generating device 4 to obtain a set value α. If larger, the direction of the rotating magnetic field is set as the measured orientation data of the capsule body 3 (step S10), and the process from S3 to S10 is repeated.

  As a result, since the capsule medical device magnetic guidance system 1 updates the orientation data of the capsule body 3 every time the operation input device 8 is operated, an error due to the state of the lumen with respect to the operation of the operation input device 8 occurs. There is nothing. Therefore, the capsule medical device magnetic guidance system 1 of the present embodiment can be operated by smoothly guiding the capsule body 3 magnetically.

  Note that the capsule medical device magnetic guidance system 1 may be configured as shown in FIGS. 12 and 13.

    As shown in FIG. 12, the magnetic field control device 5 </ b> B is based on the direction data of the rotating magnetic field generated by the rotating magnetic field generation device 4, and the direction calculation unit 71 that calculates the direction of the capsule body 3 and the feedback calculated by the control circuit 27. Based on the rate, a feedback rate adjusting unit 72 for adjusting the AC current generated by the AC current generating & controlling unit 31 is provided.

  Then, the control circuit 27 generates a rotating magnetic field based on the direction (direction) and position information of the capsule body 3 detected by the direction / position detecting device 9 according to the flowchart shown in FIG. An operation for controlling the orientation and the like is performed. The flowchart shown in FIG. 13 is substantially the same as the operation from S1 to S4 in the flowchart of the first embodiment until S14 when it is determined that the input of the operation input device 8 is detected, and the description thereof is omitted. .

  In the present modification, the rotating magnetic field is generated by the three pairs of opposing coils (helmholtz coils) 33a to 33c of the rotating magnetic field generator 4, and the alternating magnetic field for generating an induced electromotive force in the capsule coil 42 is generated. Is applied to the excitation opposing coils (Helmholtz coils) 62a to 62c, and the detection coil arrays 52a to 52c detect the magnetic field generated by the current that flows due to the induced electromotive force of the in-capsule coil 42.

  When it is determined that there is an input from the operation input device 8 (joystick) (step S14), the control circuit 27 controls the capsule body 3 in a desired direction (direction) and position according to the operation of the operation input device 8. Next, the generation condition of the next rotating magnetic field generated by the rotating magnetic field generator 4 is calculated (step S15), and the rotating magnetic field is generated (added) (step S16).

  And the capsule main body 3 changes direction (direction) and position according to the produced | generated rotating magnetic field. Here, as described above, the capsule main body 3 may move too much or be difficult to move with respect to the operation of the operation input device 8 depending on the state of the lumen, for example, the presence of body fluid or sputum or the size of the organ. Thus, the degree of ease of orientation changes, and an error that does not correspond to the calculated orientation of the capsule body 3 occurs.

  Therefore, the control circuit 27 again measures the direction (direction) and position of the capsule body 3, and performs the following control to correct the error.

    First, the control circuit 27 controls and drives the direction / position detection device 9 again to measure the direction (direction) and position data of the capsule body 3, and detects the direction (direction) of the capsule body 3 (step S17).

  Next, the control circuit 27 controls the direction calculation unit 71 to compare the direction data of the rotating magnetic field generated by the rotating field generator 4 with the direction (direction) and position data of the capsule body 3. Then, the control circuit 27 calculates the difference (Δθ, Δφ) between the direction data of the rotating magnetic field obtained from the direction calculation unit 71 and the direction (direction) data of the capsule body 3 obtained from the direction / position detection device 9. Calculate (step S18).

  Next, the control circuit 27 detects an input of the operation input device 8 (joystick) (step S19), and calculates the direction change (θ ′, φ ′) of the capsule body 3 according to the operation of the operation input device 8. Calculate (step S20).

  Then, the control circuit 27 subtracts the difference (Δθ, Δφ) obtained by multiplying the feedback rate A from the calculated change in direction (θ ′, φ ′) of the capsule body 3 and the capsule according to the operation of the operation input device 8. A change amount (change instruction amount) of the direction (direction) of the main body 3 is calculated (step S21).

Here, the direction change instruction amount (θ, φ) of the capsule body 3 according to the calculated operation of the operation input device 8 is:
(Θ, φ) = (θ′−AΔθ, φ′−AΔφ)
However, A: Feedback rate.

  Next, the control circuit 27 generates, based on the calculated direction change instruction amount (θ, φ) of the capsule body 3, the rotating magnetic field generation device 4 so as to have a direction (direction) according to the operation of the operation input device 8. Next, the generation condition of the rotating magnetic field is calculated (step S22). Then, the control circuit 27 generates (adds) a rotating magnetic field based on the calculated rotating magnetic field generation conditions (step S16), and repeats thereafter.

  As a result, the capsule medical device magnetic guidance system 1 according to the modified example can control the operation of the capsule body 3 more stably than the first embodiment.

  In the flowchart shown in FIG. 13, the feedback rate A is set to a predetermined set value in advance. However, the feedback rate A may be controlled to be variable.

    In the control described with reference to the flowchart of FIG. 11 or FIG. 13, the orientation of the capsule inner coil 42 of the capsule body 3, the exciting opposing coils (Helmholtz coils) 62a to 62c and the detection coil of the direction / position detecting device 9 are used. If the orientations of the arrays 52a to 52c coincide with each other, highly accurate direction / position detection is possible. However, if the angle of the capsule body 3 is increased, the accuracy of the direction / position detection is reduced. .

  Therefore, in order to keep the accuracy of the direction / position detection with high accuracy, the control of the flowchart shown in FIG. 14 is further added to the control described in the flowchart of FIG. That is, as shown in FIG. 14, the control circuit 27 first has excitation opposing coils (Helmholtz coils) 62 a to 62 c of the direction / position detection device 9 in the direction (direction) of the capsule body 3 that is known in advance as an initial value. The direction of the alternating magnetic field to be generated is input and set (steps S31 and S32), and the direction / position detector 9 is controlled and driven to detect the position / orientation (step S33).

  Next, the control circuit 27 calculates an angle β formed by the direction of the alternating magnetic field generated by the exciting opposing coils (helmholtz coils) 62a to 62c and the calculated direction of the capsule body 3 (step S34).

Then, the control circuit 27 compares the calculated β with a threshold value β ₀ (for example, 30 ° or 45 °) (step S35), and when this threshold value β ₀ is exceeded, the exciting counter coil is based on the calculated β. (Helmholtz coils) The direction of the alternating magnetic field generated by the 62a to 62c is set to be the direction of the capsule body 3 (step S36). Thereafter, S33 to S36 are repeated.
As a result, by applying the above control, the capsule medical device magnetic guidance system 1 causes the direction of the in-capsule coil 42 of the capsule body 3 and the exciting counter coils (helmholtz coils) 62a to 62c of the direction / position detecting device 9 to be applied. The direction of the alternating magnetic field generated by the first and second coils substantially coincides with each other. As a result, the direction of the capsule inner coil 42 of the capsule body 3, the exciting opposing coils (Helmholtz coils) 62a to 62c and the detection coils of the direction / position detecting device 9 Since the three directions of the arrays 52a to 52c substantially coincide with each other, more accurate control can be performed.

    Further, since the Helmholtz coil 62 is composed of the three sets of Helmholtz coils 62a, 62b, and 62c so as to generate magnetic fields in three axial directions, the direction of the alternating magnetic field can be arbitrarily set.

  The capsule coil 42 constituting the resonance circuit 40 of the capsule body 3 may be configured as shown in FIG. 15, for example.

    As shown in FIGS. 15A and 15B, the intra-capsule coil 42 is wound around a covering member 81 that covers the built-in material of the capsule body 3, and the outer periphery thereof is coated with a resin material. The covering member 81 is formed of a high permeability foil that is a high permeability member such as permalloy, nickel, or iron, and is formed in an arc shape to prevent eddy currents.

Further, as shown in FIG. 15C, the intra-capsule coil 42 may be configured to be wound around a rod-shaped member 82 formed of a high magnetic permeability member such as permalloy, nickel, or iron. In FIGS. 15A, 15B, and 15C, the spiral protrusion (or screw portion) 12 is omitted.
Thereby, the capsule body 3 can further strengthen the magnetic field generated by the resonance circuit 40 configured by the intracapsule coil 42, and can improve the direction / position accuracy by the direction / position detection device 9.

  Further, a power supply circuit as shown in FIG. 16 may be configured using the resonance circuit 40 configured by the capsule coil 42 to supply power.

    A power supply circuit 90A shown in FIG. 16A is configured by providing two changeover switches 91 at both ends of the capsule coil 42, connecting the capacitor 41 to the terminal a side, and connecting the power circuit 92 to the terminal b side. Has been. The output side of the power supply circuit 92 has one end connected to each circuit inside the capsule and the other end connected to a secondary battery or a super capacitor.

  The change-over switch is controlled by the control circuit 27. In the case of direction / position detection by the direction / position detection device 9, the change-over switch is switched to the terminal a side to form the resonance circuit 40 to supply power. In this case, the terminal b is switched to be connected to the power supply circuit 92.

  A power supply circuit 90B shown in FIG. 16B is configured by connecting a resonance circuit 40 and a power circuit 92 to the power supply circuit 90A by a transformer 93. Thereby, the power supply circuit 90B can reduce the influence of the power supply on the direction / position detection by the direction / position detection device 9 as compared with the power supply circuit 90A.

  A power supply circuit 90C shown in FIG. 16C is configured by connecting the resonance circuit 40 and the power circuit 92 via two changeover switches 94 to the power supply circuit 90B. By configuring the power supply circuit, it is possible to supply power to the capsule body 3.

  It should be noted that embodiments configured by partially combining the above-described embodiments and the like also belong to the present invention.

[Appendix]
(Additional item 1)
A magnet provided in the capsule medical device body inserted into the body cavity;
First magnetic field generating means for generating a magnetic field in an arbitrary direction;
A thrust generating mechanism for generating a thrust in the capsule medical device main body by the action of the magnetic field generated by the first magnetic field generating means and the magnet;
Direction detecting means for detecting the direction of the capsule medical device body;
Control means for controlling the magnetic field generated by the first magnetic field generating means based on the orientation information of the capsule medical device body detected by the orientation detecting means;
A capsule medical device magnetic guidance system comprising:

(Appendix 2)
The direction detection means includes
A coil provided in the capsule medical device body;
Second magnetic field generating means for generating an alternating magnetic field for generating an induced electromotive force in the coil provided in the capsule medical device body;
Magnetic field detection means for detecting magnetic field intensity from the coil provided in the capsule medical device body;
A calculation unit that receives a detection value from the magnetic field detection unit and calculates an orientation and a position of the capsule medical device body;
The capsule medical device magnetic guidance system according to Additional Item 1, further comprising:

(Appendix 3)
The capsule medical device magnetic guidance system according to Item 2, wherein a capacitor is connected to the coil to constitute a resonance circuit.

(Appendix 4)
A magnet provided in the capsule medical device body inserted into the body cavity;
First magnetic field generating means for generating a magnetic field in an arbitrary direction;
A thrust generating mechanism for generating a thrust in the capsule medical device main body by the action of the magnetic field generated by the first magnetic field generating means and the magnet;
Direction and position detection means for detecting the direction and position of the capsule medical device body;
Control means for controlling the magnetic field generated by the first magnetic field generation means based on the orientation and position information of the capsule medical device body detected by the orientation and position detection means;
A capsule medical device magnetic guidance system comprising:

(Appendix 5)
The orientation and position detection means is
A coil provided in the capsule medical device body;
Second magnetic field generating means for generating an alternating magnetic field for generating an induced electromotive force in the coil provided in the capsule medical device body;
Magnetic field detection means for detecting magnetic field intensity from the coil provided in the capsule medical device body;
A calculation unit that receives a detection value from the magnetic field detection unit and calculates an orientation and a position of the capsule medical device body;
Item 6. The capsule medical device magnetic guidance system according to Item 4, further comprising:

(Appendix 6)
6. The capsule medical device magnetic guidance system according to claim 5, wherein a capacitor is connected to the coil to form a resonance circuit.

(Appendix 7)
The first magnetic field generating means is a rotating magnetic field generating means for generating a rotating magnetic field;
The capsule medical device magnetic guidance system according to Additional Item 1 or 4, wherein the thrust generation mechanism is a spiral structure provided in the capsule medical device body.

(Appendix 8)
The control means includes a normal direction of a magnetic field rotation plane of the rotating magnetic field generated by the rotating magnetic field generating means and an orientation of the capsule medical device body detected by the orientation detecting means or the orientation and position detecting means. 9. The capsule medical device magnetic guidance system according to appendix 8, wherein the rotating magnetic field generating means is controlled so that the angle is equal to or less than a set value.

(Appendix 9)
The capsule medical device magnetic guidance system according to claim 1 or 4, wherein the major axis direction of the capsule medical device body and the direction of the coil are configured substantially parallel to each other.

(Appendix 10)
6. The capsule medical device magnetic guidance system according to Additional Item 2 or 5, wherein the second magnetic field generation device is configured by at least one pair of opposed coils.

(Appendix 11)
The second magnetic field generator is two or three sets of opposing coils arranged so as to be orthogonal to each other,
The control means is configured so that the angle formed by the direction of the magnetic field generated by the two or three sets of counter coils and the direction of the capsule medical device body calculated by the calculation means is equal to or less than a set value. The capsule medical device magnetic guidance system according to Additional Item 2 or 5, wherein the direction of the magnetic field generated by the control is controlled.

(Appendix 12)
6. The capsule medical device magnetic guidance system according to claim 2 or 5, further comprising a power supply circuit connected to the coil, wherein power is supplied to an internal circuit of the capsule medical device body by the power supply circuit.

(Additional Item 13)
A primary side of a transformer is connected to the resonance circuit, a secondary coil of the transformer is connected to a power supply circuit, and power is supplied to the internal circuit of the capsule medical device body by the power supply circuit. Item 6. The capsule medical device magnetic guidance system according to Item 2 or 5.

(Appendix 14)
The control means has an input means for changing the orientation of the capsule medical device body, and information of the input means and the orientation of the capsule medical device body detected by the orientation detection means or the orientation and position detection means. 6. The capsule medical device magnetic guidance system according to Additional Item 2 or 5, wherein the first magnetic field generation unit is controlled based on the information.

(Appendix 15)
The capsule medical device magnetic guidance system according to Additional Item 9, wherein the coil is formed on an outer peripheral surface of the capsule medical device body.

(Appendix 16)
Item 16. The capsule medical device magnetic guidance system according to Item 15, wherein a high permeability member is disposed on the inner space side of the coil.

(Appendix 17)
Item 17. The capsule medical device magnetic guidance system according to Item 16, wherein the high magnetic permeability member is formed of a high magnetic permeability foil.

(Appendix 18)
13. The capsule medical device magnetic guidance system according to appendix 12, wherein switching means for switching a connection state between the power supply circuit and the coil is provided.

(Appendix 19)
13. The capsule medical device magnetic guidance system according to appendix 12, wherein switching means for switching a connection state is provided between the capacitor and the coil.

(Appendix 20)
13. The capsule medical device magnetic guidance system according to additional items 10 to 12, wherein the counter coil is a Helmholtz coil.

1 is an overall configuration diagram of a capsule medical device magnetic guidance system of one embodiment. It is a circuit block diagram of the capsule medical device magnetic guidance system of FIG. It is side surface explanatory drawing of a capsule main body. It is explanatory drawing of the mode of a change of the rotating magnetic field when a rotating magnetic field is applied. It is explanatory drawing of the direction / position detection by the direction / position detection apparatus with respect to a capsule main body. It is explanatory drawing which shows a rotating magnetic field generator and a direction / position detection apparatus. FIG. 7 is an enlarged perspective view of the rotating magnetic field generation device and the direction / position detection device of FIG. 6. FIG. 8 is a cutaway view of the rotating magnetic field generation device and the direction / position detection device of FIG. 7. It is a perspective view which shows the modification of the direction / position detection apparatus of FIG. FIG. 10 is a cutaway view of the rotating magnetic field generation device and the direction / position detection device of FIG. 9. It is a flowchart which shows the operation | movement which controls the direction of a rotating magnetic field, etc. based on the direction (direction) and position information of a capsule main body detected by the direction / position detection apparatus. FIG. 6 is a circuit block diagram showing a modification of the direction / position detection device of FIG. 2. 13 is a flowchart showing an operation for controlling the direction of a rotating magnetic field and the like based on the direction (direction) and position information of the capsule body detected by the direction / position detection device of FIG. It is a flowchart which shows the control further added to the flowchart of FIG. 11 or FIG. It is explanatory drawing of the capsule main body which shows the modification of the coil which comprises the resonance circuit. It is a circuit block diagram which shows the power supply circuit comprised using the resonance circuit comprised by the coil of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capsule type medical device magnetic guidance system 3 Capsule body 4 Rotating magnetic field generator 5 Magnetic field controller 6 Processing device 7 Display device 8 Operation input unit 8a Direction input device 8b Speed input device 8c Function button 9 Direction / position detection device 12 Spiral Protrusion 16 Magnet 20 Signal processing circuit 26 Data processing circuit 27 Control circuit 31 AC current generation & control unit 32 Driver unit 33a to 33c Electromagnet 40 Resonance circuit 41 Capacitor 42 Capsule coil 51 (51a to 51c) Excitation coil array 52 (52a to 52a 52c) Detection coil array 53 Signal measuring device 54 Arithmetic processing unit 55 Oscillator 61, 63 Sense coil 62 (62a to 62c) Exciting counter coil (Helmholtz coil)

Claims (6)

It is provided with direction detection means for detecting the direction of the capsule medical device body, and this direction detection means
A coil provided in the capsule medical device body;
Magnetic field generating means for generating an alternating magnetic field for generating an induced electromotive force in the coil provided in the capsule medical device body;
Magnetic field detection means for detecting magnetic field intensity from the coil provided in the capsule medical device body;
Receiving a detection value from the magnetic field detection means, and calculating means for calculating the orientation and position of the capsule medical device body,
The capsule medical device direction position detection system, wherein the magnetic field generating means is constituted by at least one pair of opposing coils. The magnetic field generating means are two or three sets of opposed coils arranged to be orthogonal to each other,
The magnetic field generated by the counter coil so that the angle formed by the direction of the magnetic field generated by the two or three sets of counter coils and the direction of the capsule medical device body calculated by the calculation means is less than a set value. The capsule medical device direction position detection system according to claim 1, further comprising control means for controlling the orientation of the capsule medical device.   The capsule medical device direction position detection system according to claim 1, wherein a major axis direction of the capsule medical device body and a direction of the coil are substantially parallel.   4. The capsule medical device direction position detection system according to claim 3, wherein the coil is formed on an outer peripheral surface of the capsule medical device body.   The capsule medical device direction position detection system according to claim 3, wherein a high permeability member is disposed on the inner space side of the coil.   6. The capsule medical device direction position detection system according to claim 5, wherein the high magnetic permeability member is formed of a high magnetic permeability foil.

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