JP2007130175A - Endoscope insertion part shape recognition system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately reproduce and display the shape of a curved part in the insertion part of an endoscope by simple constitution. <P>SOLUTION: Many coils S1-Sn are arranged on an endoscope insertion part 12 at prescribed intervals. The coil S1 is provided on an endoscope distal end 12C, the coil S3 is provided on a rigid member 121 provided on the boundary with the curved part 12B of a soft part 12A, and the coil S2 is provided on a curved piece 122A positioned at the almost center inside the curved part 12B. Strain gauges 20 and 21 are arranged respectively between the distal end 12C and the curved piece 122A and between the rigid member 121 and the curved piece 122A. The positions of the coils S1, S2 and S3 are detected by using an AC magnetic field by a magnetic field generator. The relation of the resistance value of the strain gauges 20 and 21 and the curvature of the curved part 12B is stored in a ROM provided in the connector of each endoscope and the curvature of the curved part 12B is obtained. From the positions of the coils S1-S3 and the curvature, the shape of the curved part 12B is reproduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an apparatus that detects the position of an endoscope insertion portion during insertion and displays the shape thereof.

  It is useful for the surgeon to grasp the shape of the endoscope insertion portion inserted into the body. In particular, in the use of a lower endoscope that is difficult to insert into the body, grasping the shape of the endoscope insertion portion is extremely useful. From these facts, various systems for grasping the shape of the endoscope insertion portion have been proposed.

  A system using an alternating magnetic field is known as a system for displaying the shape of the endoscope insertion portion. This is because a number of magnetic sensor coils are arranged at predetermined intervals along the longitudinal direction in the insertion portion, and the position of each coil in the three-dimensional space and the electromagnetic induction action between the alternating magnetic field and the coil are used. The direction is detected. The shape of the endoscope insertion portion is reproduced by applying a three-dimensional spline curve or the like to the position data of the measurement point where the coil is arranged, and displayed on the monitor.

  The endoscope insertion portion is generally divided into a bending portion connected to the distal end portion and a flexible portion connecting the operation portion and the bending portion. The bending portion is a portion that is bent in conjunction with operation of a knob provided in the operation portion. On the other hand, the soft part is a part that bends freely.

  As schematically shown in FIG. 7, the flexible portion 120 </ b> A is composed of a spiral tube 123, and the bending portion 120 </ b> B is composed of a large number of bending pieces 121. The bending pieces 121 are connected to each other by a hinge portion 122 so that the bending pieces 121 can be bent. FIG. 8 schematically shows another structure of the bending portion 120B. In the example of FIG. 8, the bending portion 120B includes two types of bending pieces 121A and 121B. In the configuration of FIG. 8, a bending piece 121A having a narrower width than the bending piece 121B on the soft part side is used on the bending part front end side, and the leading end side of the bending part 120B can be bent with a larger curvature than the soft part side.

  From the structure shown in FIGS. 7 and 8, when the bending portion is bent by the knob operation, the curvature is extremely larger than the curvature due to the natural bending of the soft portion. Further, the manner of bending is also greatly different, and as shown in FIG. 9, even the same bending portion 120B is bent with a plurality of different curvatures. Therefore, the shape of the curved portion cannot be accurately reproduced by the same method as the shape reproduction of the soft portion.

In order to solve the above problem, there is known a technique in which the number of coils installed in the bending portion is increased and the arrangement thereof is made dense so that the shape reproduction of the bending portion is accurately performed (Patent Document 1).
JP 2000-93386 A

  However, the installation of a large number of coils in the bending portion limits the curvature that the bending portion can tolerate, and also reduces the durability of the coil and the bending portion. Moreover, an increase in the number of parts, an increase in the size of the curved portion, and the like are caused.

  An object of the present invention is to provide an endoscope insertion portion shape grasping system capable of reproducing the shape of an insertion portion with a simple configuration.

  An endoscope insertion portion shape grasping system according to the present invention is an endoscope insertion portion shape grasping system for grasping the shape of a flexible endoscope insertion portion, and includes both ends of a bending portion in the insertion portion. A position detecting means for detecting the position of at least one point in the bending portion, a bending state detecting means for detecting bending states at both ends of the bending portion and a plurality of positions in the bending portion, and at both ends of the bending portion It is characterized by comprising a position, a position of a point in the bending portion, and a bending portion shape reproducing means for reproducing the shape of the bending portion from a bending state at a plurality of positions.

  The endoscope insertion portion shape grasping system further includes a bending direction detecting means for detecting the bending direction of the bending portion. The bending direction detection means is provided, for example, on an angle knob of an endoscope, and includes a sensor that detects an operation direction of the angle knob.

  The position detection means uses, for example, an alternating magnetic field. More specifically, the position detection means includes a magnetic field generator that generates the alternating magnetic field and a plurality of coils for magnetic sensors that are disposed in the insertion portion that detects the alternating magnetic field. It consists of.

  The bending state detection means includes a strain gauge that extends to the insertion portion, and the endoscope insertion portion shape grasping system includes a memory that stores a relationship between the output of the strain gauge and the curvature of the bending portion. At this time, the bending portion shape reproducing means reproduces the shape of the bending portion using the curvature. Further, for example, the memory is provided in each connector portion of each endoscope.

  Furthermore, the endoscope insertion part shape grasping system includes a soft part shape reproducing unit that reproduces the shape of the soft part in the insertion part.

  As described above, according to the present invention, it is possible to provide an endoscope insertion portion shape grasping system that can reproduce the shape of an insertion portion with a simple configuration.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of an endoscope to which an endoscope insertion portion shape grasping system according to an embodiment of the present invention is applied. In the present embodiment, an electronic endoscope is employed as the endoscope.

  The electronic endoscope 10 includes an operation unit 11 for an operator to hold and operate. An insertion portion 12 and a light guide cable 13 are connected to the operation portion 11, and a connector 13 </ b> A is provided at the tip of the light guide cable 13. The connector 13A is detachably attached to a processor device (not shown) in which, for example, a light source and a video signal processing circuit are integrally accommodated, and the processor device is passed through the connector 13A of the electronic endoscope 10, the light guide cable 13, and the like. Illumination light is supplied into the body cavity from the light source unit, and an image signal from the electronic endoscope 10 is supplied to the video signal processing circuit of the processor device.

  The insertion portion 12 includes a flexible portion 12A, a bending portion 12B, and a distal end portion 12C. The flexible portion 12 </ b> A is a flexible tube that is freely bent, occupies most of the insertion portion 12, and is directly connected to the operation portion 11. The bending portion 12B is provided in a section connecting the tip portion 12C and the flexible portion 12A, and the direction of the tip portion 11C rotates, for example, by about 270 ° in conjunction with the rotation operation of the angle knob 11A provided in the operation portion 11. Bendable until done. As will be described later, an imaging optical system, an imaging element, an illumination optical system, and the like are mounted on the distal end portion 12C.

  FIG. 2 is a partial enlarged view schematically showing a configuration around the bending portion 12B in the insertion portion 12. As shown in FIG.

  The distal end portion 12C of the endoscope insertion portion 12 has a rigid configuration, and the imaging element 15 and the distal end 16A of the light guide (optical fiber bundle) 16 are disposed therein. The distal end portion 12C of the insertion portion 12 is provided with an illumination optical system 16B for irradiating light from the light guide 16 and an image pickup optical system 15A for forming a subject image on the image pickup device 15.

  An annular hard member 121 is provided at the boundary between the flexible portion 12A and the curved portion 12B. The bending portion 12B is provided with a large number of bending pieces 122 as is conventionally known, and the bending pieces 122 are sequentially connected in a chain form from the distal end portion 12C to the rigid member 121.

  Further, the coil S1 is disposed at the distal end portion 12C, and the coil S2 is disposed at the bending piece 122A (the bending piece colored in FIG. 2) located at the approximate center of the bending portion 12B, and the rigid member 121 is disposed. Is provided with a coil S3. Coils S4, S5, S6,..., Sn are sequentially provided at predetermined intervals along the longitudinal direction of the flexible portion 12A further on the operation unit 11 side than the coil S3. Note that the coils S1 to Sn are, for example, coils for a magnetic sensor, and only the coils S1 to S3 are illustrated in FIG.

  In the present embodiment, the bending part 12B is provided with bending sensors 20 and 21 for detecting the bending state of the bending part 12B along the axial direction of the bending part 12B. The bending sensors 20 and 21 are sensors for detecting the degree of bending of the bending portion 12B, and strain gauges are used in this embodiment. One end of the strain gauge 20 is fixed to the distal end portion 12C by the fixing portion 20A, and one end of the strain gauge 21 is fixed to the rigid member 121 by the fixing portion 21A.

  On the other hand, the end 20B of the strain gauge 20 on the side opposite to the fixed part 20A and the end 21B of the strain gauge 21 on the side opposite to the fixed part 21A extend to the bending piece 121A, respectively. Further, the end portions 20B and 21B are engaged with the bending piece 121A by the guide 123 so that the end portions 20B and 21B can only slide along the axial direction of the bending portion 12B when the bending portion 12B is bent. Combined.

  That is, as shown in FIGS. 2 and 3, the inner surface of the bending piece 121 </ b> A is arranged along the axial direction so as to regulate other than the movement along the axial direction of the bending portion 12 </ b> B of the end portions 20 </ b> B and 21 </ b> B. An extending guide 123 is provided. Openings are provided at both ends in the longitudinal direction of the guide 123, and the end portions 20B and 21B are guided from the both ends of the guide 123 into the guide 123, respectively. In the present embodiment, the end portions 20B and 21B are arranged apart from each other by a predetermined distance so as not to contact each other in the guide 123. FIG. 3 is a partially enlarged cross-sectional view in a cross section perpendicular to the axis of the bending portion 12B schematically showing the relationship between the guide 123 provided on the bending piece 122A and the end portions 20B and 21B.

  FIG. 4 is a block diagram showing an electrical configuration of the entire electronic endoscope system of the present embodiment. In the present embodiment, the electronic endoscope system detects the position of the insertion unit 12 and displays the shape of the insertion unit shape grasping system, and the distal end of the insertion unit 12 captures an image. And a captured image display system for displaying images.

  The captured image display system supplies the illumination light to the image sensor 15 and the light guide 16 provided in the endoscope insertion unit 12 and the light guide 16, and drives the image sensor 15 and images are captured by the image sensor 15. It mainly comprises a light source / signal processing unit 30 for processing a video signal of an image and an image display device (not shown) for displaying a captured image.

  On the other hand, the insertion portion shape grasping system reproduces the plurality of magnetic sensor coils S1 to Sn provided in the endoscope insertion portion 12, the insertion portion shape grasping unit 40, and the insertion portion shape as described above. The image display device 41 and the magnetic field generator 42 are mainly configured.

  In the present embodiment, the light source / signal processing unit 30 and the insertion portion shape grasping unit 40 are provided in a processor device to which the electronic endoscope 10 is detachably mounted. That is, the signal line of the image sensor 15, the light guide 16, the signal lines of the coils S1 to Sn, the signal lines of the strain gauges 20 and 21, and the like are guided into the processor device via the light guide cable 13 and the connector 13A.

  The signal cables of the light guide 16 and the image sensor 15 are connected to the light source / signal processing unit 30 in the processor device. The image sensor 15 is driven by an image sensor driver 300 provided in the light source / signal processing unit 30, and the video signal output from the image sensor 15 is sent to the preceding signal processing circuit 301 of the light source / signal processing unit 30.

  Video signals that have undergone predetermined signal processing in the upstream signal processing circuit 301 are temporarily stored in the image memory 302 and then sequentially sent to the downstream signal processing circuit 303. The post-stage signal processing circuit 303 performs predetermined image signal processing on the video signal, and then encodes the video signal and outputs it to an output device such as an image display device.

  The driving of the image sensor driver 300 and the image memory 302 is controlled by the timing controller 304, and the timing controller 304 is controlled by the system controller 305.

  In-vivo imaging using the image sensor 15 is performed using illumination light irradiated through the light guide 16, and the illumination light is supplied from the light source unit in the processor device to the light guide 16. . The light source unit includes a lamp 306, and white light emitted from the lamp 306 is condensed on the end surface of the light guide 16 inserted into the processor device via the shutter 307 and the condenser lens 308.

  Electric power is supplied to the lamp 306 from the lamp power supply 309, and the shutter 307 is driven by a motor 310 that is driven and controlled by a motor driver 311. The lamp power supply 309 and the motor driver 311 are controlled by the system controller 305.

  The system controller 305 is connected to a front panel switch (F panel switch) 312 having switches that are operated by a user. The system controller 305 electronically responds to a switch operation on the front panel switch 312. Various settings in the endoscope system can be changed.

  In addition, the ROM 130 is mounted in the connector 13A of the electronic endoscope 10, and when the connector 13A is attached to the processor device, the ROM 130 is connected to the system controller 305 and the electronic endoscope identification information stored in the ROM 130 is stored. Is read out. That is, the ROM 130 stores information related to the electronic endoscope 10, such as a model and various parameters related to image processing, and these information are read by the system controller 305.

  On the other hand, signals from the magnetic sensor coils S1 to Sn are input to the signal switching circuit 134 in the connector 13A via, for example, the multi-channel amplifier 131 in the connector 13A. Further, the resistance change in the strain gauges 20 and 21 is detected by the strain gauge circuits 132 and 133 provided in the connector 13A, and is input to the signal switching circuit 134 in the same manner as the signals of the coils S1 to Sn.

  Furthermore, in this embodiment, the angle knob sensor 11B for detecting the operation direction (rotation direction) of the angle knob 11A is provided in the angle knob 11A of the operation unit 11, and the signal from the angle knob sensor 11B is also a light guide. 13 to the signal switching circuit 134 provided in the connector 13A.

  The signal switching circuit 134 is a circuit for selectively outputting the input signals of the coils S1 to Sn, the signals of the strain gauges 20 and 21, and the signal of the angle knob sensor 11B sequentially at a predetermined timing. Each signal is sent to the A / D converter 400 in the insertion portion shape grasping unit 40, converted from an analog signal to a digital signal, and then input to the control calculation unit 401. The selection of the output signal in the signal switching circuit 134 and the switching timing thereof are controlled by a control signal from the control calculation unit 401 of the insertion portion shape grasping unit 40.

  In the control calculation unit 401, the positions of the coils S1 to Sn are calculated from the signals of the coils S1 to Sn, for example. The degree of strain of the strain gauges 20 and 21 is calculated from the signals of the strain gauges 20 and 21, and the bending direction of the bending portion 12B is calculated from the signal of the angle knob sensor 11B.

  In the image display control unit 402, based on the position data of the coils S1 to Sn calculated in the control calculation unit 401, the data related to bending obtained by the strain gauges 20 and 21, and the data related to the bending direction obtained by the angle knob sensor 11B. Thus, image data that reproduces the shape of the entire insertion section 12 (for example, image data drawn by an interpolation curve that connects coil positions) is created and output to the image display device 41.

  The positions of the magnetic sensor coils S1 to Sn are detected by detecting the electromagnetic induction action of the coils S1 to Sn by the alternating magnetic field generated by the magnetic field generator 42, as is conventionally known. The magnetic field generator 42 generates an alternating magnetic field in a time series, for example, in a direction corresponding to each coordinate axis XYZ of the orthogonal coordinate system XYZ, and driving of the magnetic field generator 42 is controlled by a drive circuit XYZ403. The timing controller 404 controls the drive timings of the control calculation unit 401, the image display control unit 402, and the drive circuit XYZ 403.

  FIG. 5 illustrates positions P1 to P5 of the coils S1 to S5 in a state where the angle knob 11A is operated and the bending portion 12B is greatly bent, and a state when these are interpolated (fitted) using appropriate curves. This is a schematic diagram showing a curved state until the direction of the end face of the distal end portion 12C is rotated by approximately 270 °.

  In FIG. 5, the portion corresponding to the curved portion 12B is drawn with a solid line, and the portion corresponding to the flexible portion 12A is drawn with a broken line. As illustrated in FIG. 5, the soft portion 12A draws a very gentle curve compared to the curved portion 12B, and the points P3 to Pn corresponding to the soft portion 12A are connected with a Bezier curve, a spline curve, or the like with sufficient accuracy. The shape can be reproduced.

  On the other hand, the bending portion 12B is generally different in structure from the flexible portion 12A, and greatly differs in how the force is applied, such as being given force by an angle wire. Therefore, in the bending portion 12B, the way of bending is also significantly different from that of the flexible portion 12A, and when the same method as the flexible portion 12A is used for interpolation in the bending portion 12B as in the prior art, the shape of the insertion portion 12B to be reproduced is the actual shape. There are cases where it is significantly different from the above.

  For example, as shown in FIG. 5, the curved portion 12B is curved with an extremely large curvature compared to the flexible portion 12A, and the curve cannot generally be expressed by a single curvature. Therefore, in the present embodiment, the positions of both ends of the bending portion 12B and at least one point in the bending portion 12B are detected, and for example, the degree of bending is detected for each section divided by each detected position. Based on the data, the shape of the bending portion 12B is more accurately grasped, and the shape of the bending portion 12B is more accurately reproduced and displayed on the image display device as shown in FIG. .

  The bending method of the bending portion 12B is generally characteristic for each product. Therefore, in this embodiment, for example, the relationship between the output from the strain gauges 20 and 21 and the data (for example, curvature) indicating the curved shape in each corresponding section is described for each endoscope 10 as a lookup table, for example. Recorded in a ROM (memory) 130 in advance.

  Based on the data in the ROM 103, the control calculation unit 401 obtains the degree of curvature (for example, curvature) in each section from the signal output of the strain gauges 20 and 21. As a result, the curvature of the sections S1-S2 and S2-S3 of the bending section 12B, the positions of the points P1, P2, P3, and the direction in which the bending section 12B is bent are specified, and the shape of the bending section 12B is accurately reproduced. can do.

  As is well known in the art, the strain gauges 20 and 21 are generally formed by attaching a resistor such as a wire gauge to a base (a thin plate of an electrical insulator), and resistance due to deformation of the object to be measured. By detecting a change in the resistance value of the body, the deformation of the object to be measured is detected.

  That is, in the present embodiment, for example, the relationship between the resistance value R of the strain gauges 20 and 21 and the section curvature ρ of the bending portion 12B is measured in advance, and is stored in the ROM 130 provided in the connector 13A of the electronic endoscope 10. Stored before shipment. When the connector 13A of the electronic endoscope is attached to the processor device, these data are read from the ROM 130 together with the endoscope identification number and transferred to the control calculation unit 401.

  FIG. 6 is a graph schematically illustrating the relationship between the curvature ρ and the resistance value R. In FIG. 6, whether the curvature ρ is positive or negative is determined based on a signal from the angle knob sensor 11B.

  As described above, according to the present embodiment, the shape of the curved portion 12C and the flexible portion 12A is reproduced by different complementary methods, and the shape of the entire insertion portion 12 is more accurately reproduced by combining these. That is, the shape of the flexible portion 12A is displayed from the position of each coil using a conventionally known Bezier curve, spline curve, or the like, and from the curved portion 12B to the tip portion 12C, the coils S1, S2, and S3 are displayed. Bends divided by the positions (positions at both ends of the bending portion 12B and at least one position in the bending portion 12B), the bending direction of the bending portion 12B detected by the angle knob sensor 11B, and the positions of the coils S1, S2, and S3. The shape is reproduced and displayed based on the curvature in each section obtained from the signals of the strain gauges 20 and 21 corresponding to each section of the section 12B.

  When a Bezier curve, a spline curve, or the like is used for the interpolation curve of the soft part 12A, the control point for the point P2 of the interpolation curve of the soft part 12A is, for example, the tangent or curvature of the interpolation curve selected for the bending part 12B Determined with reference to the geometric parameters of

  As described above, according to the present embodiment, the shape of the curved portion can be more accurately reproduced with a simple configuration, and thereby the shape of the entire insertion portion can be more accurately reproduced. .

  In the present embodiment, the AC magnetic field generated by the magnetic field generator installed outside is detected using the coil provided in the endoscope insertion unit, but the magnetic field generating coil is provided in the endoscope insertion unit. This may be configured to be detected by a sensor installed outside.

  Further, the number of coils provided in the bending portion may be two or more, and the number of bending sensors (strain gauges) may be three or more.

  In this embodiment, the relationship between the resistance value of the strain gauge and the curvature of the bending portion is stored in the memory provided in the endoscope connector portion, but may be stored in the memory of a processor device or a computer, for example. . In such a case, for example, data is stored in the memory for each endoscope type (model number), and the endoscope model numbers are displayed in a list on the screen, and by selecting the corresponding model number from these It is good also as a structure which acquires corresponding data. Moreover, it is good also as a structure which selects automatically the data corresponding to a model number.

1 is an overview diagram of an endoscope to which an endoscope insertion portion shape grasping system according to an embodiment of the present invention is applied. It is the elements on larger scale which show typically the structure near a curved part. It is a partial expanded sectional view in a section perpendicular to an axis of a curved part which shows typically a relation between a guide provided in a curved piece, and an end of a strain gauge. It is a block diagram which shows the electric constitution of the whole electronic endoscope system of this embodiment. It is a figure which shows the state which fitted the positions P1-P5 of coils S1-S5 in the state in which the bending part was greatly curved, and these using the appropriate curve. It is a graph which illustrates typically the relation between curvature ρ and resistance value R. It is a figure which shows typically an example of the structure of an endoscope bending part. It is a figure which shows typically the structure of the endoscope bending part different from FIG. It is a schematic diagram of the curved part curved by the several different curvature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 (Electronic) endoscope 12 Insertion part 12A Soft part 12B Bending part 12C Tip part 20, 21 Bending sensor (strain gauge)
40 Insertion part shape grasping unit 41 Image display device 42 Magnetic field generator 130 ROM
401 Control Calculation Unit 402 Image Display Control Unit S1 to Sn Magnetic Sensor Coil

Claims (9)

An endoscope insertion portion shape grasping system for grasping the shape of a flexible endoscope insertion portion,
Position detecting means for detecting positions of both ends of the bending portion in the insertion portion, and a position of at least one point in the bending portion;
Bending state detection means for detecting each bending state at a plurality of positions of the bending portion;
An endoscope insertion portion shape comprising: the positions of both ends, the positions of points in the bending portion, and bending portion shape reproducing means for reproducing the shape of the bending portion from the bending state at the plurality of positions. Grasp system.   The endoscope insertion portion shape grasping system according to claim 1, further comprising a bending direction detecting means for detecting a bending direction of the bending portion.   The endoscope insertion portion shape grasping system according to claim 2, wherein the bending direction detection means is provided on an angle knob of an endoscope and is configured by a sensor that detects an operation direction of the angle knob. .   The endoscope insertion portion shape grasping system according to claim 1, wherein the position detecting means uses an alternating magnetic field.   The said position detection means is comprised from the magnetic field generator which generate | occur | produces an alternating magnetic field, and the some coil for magnetic sensors arrange | positioned at the said insertion part which detects the said alternating magnetic field. Endoscope insertion part shape grasping system.   The endoscope insertion portion shape grasping system according to claim 1, wherein the bending state detection means includes a strain gauge extending to the insertion portion.   7. A memory for storing a relationship between an output of the strain gauge and a curvature of the bending portion, wherein the bending portion shape reproducing means reproduces the shape of the bending portion using the curvature. Endoscope insertion part shape grasping system described in 1.   The endoscope insertion portion shape grasping system according to claim 7, wherein the memory is provided in each connector portion of each endoscope. The endoscope insertion part shape grasping system according to claim 1, further comprising a soft part shape reproduction unit that reproduces a shape of the soft part in the insertion part.

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