WO2017010244A1 - Endoscope system, endoscope apparatus, and insertion shape calculation method - Google Patents

Abstract

This endoscope system 1, which acquires an image captured inside a subject, is provided with: a detection device 50 that detects electromagnetic waves radiated in accordance with a coil driving signal and that outputs a response signal; a coil 40 that radiates electromagnetic waves toward the detection device by using the applied coil driving signal; a transmission line 60 through which signals are transmitted between an oscillator and the coil; and an insertion shape calculation unit that obtains the distance between the coil and the detection device on the basis of an output timing at which the coil driving signal is outputted from the oscillator and a reception timing at which the response signal from the detection device is received, and that calculates an insertion shape of an insertion part on the basis of the distance.

Description

Endoscope system, endoscope apparatus, and insertion shape calculation method

The present invention relates to a technique for analyzing an insertion portion shape of an endoscope apparatus in an endoscope system.

There are two types of endoscopy: upper endoscopy and lower endoscopy. In any case, the endoscope operator needs to perform an appropriate operation based on the shape of the insertion portion of the endoscope apparatus and the insertion position in the body cavity of the patient as the subject. It is common for a doctor who is an operator to determine the shape of the insertion portion of the endoscope apparatus based on experience or the like. For this reason, it may be difficult for inexperienced residents and third parties to easily grasp the shape of the insertion portion of the endoscope apparatus.

Therefore, a technique for observing the shape of the insertion portion of the endoscope apparatus in the body cavity has been proposed. For example, according to Patent Document 1, a plurality of magnetic coils are incorporated in an insertion portion of an endoscope, and a position detection unit (coil unit) that receives magnetism generated from the magnetic coil is provided, whereby the shape of the insertion portion is changed. Obtainable.

JP 2010-88573 A

By using the technique described in Patent Document 1 above, it is possible to obtain the shape of the endoscope apparatus insertion portion. However, in the endoscope system described in Patent Document 1, an antenna unit is added and the antenna unit needs to be installed separately from the endoscope apparatus, so that the configuration of the endoscope system becomes large. End up. At the same time, depending on the surrounding environment, the antenna unit is susceptible to noise and the like. Furthermore, the above configuration cannot be applied to a portable endoscope apparatus.

An object of the present invention is to provide an endoscope system that acquires an insertion shape of an endoscope apparatus insertion portion with a compact configuration.

In order to achieve the above object, an endoscope system for acquiring a captured image in an object by inserting an insertion unit of an endoscope apparatus into the object, an oscillator for outputting a coil drive signal; A detection device that is provided in the insertion portion and detects an electromagnetic wave radiated based on the coil drive signal and outputs a response signal; and a detection device provided in the insertion portion and applied to the detection device by the applied coil drive signal. A coil that radiates electromagnetic waves, a transmission line that is provided in the insertion portion and transmits a signal between the oscillator and the coil, an output timing at which a coil drive signal is output from the oscillator, and a response signal from the detection device. An insertion shape for obtaining a distance between the coil and the detection device from a reception timing to be received and calculating an insertion shape of the insertion portion based on the distance It includes a detecting section, a.

According to the present invention, it is possible to provide an endoscope system that acquires the insertion shape of the endoscope apparatus insertion portion with a compact configuration.

1 is an external view of an endoscope system according to the present embodiment. It is a whole block diagram which shows the internal structure of an endoscope system. It is the figure which cut the insertion part in the plane perpendicular to the insertion direction. It is the figure which cut the insertion part inserted in the body cavity in the plane parallel to the insertion direction. It is a wiring diagram of a type in which one transmission line is wired to each coil. It is a wiring diagram of a type in which a common transmission line is wired to each coil. It is a functional block diagram for demonstrating the control processing by CPU. It is a figure which shows a mode that a coil drive signal is output from an oscillator and a response signal returns. It is a figure which shows the timing which the corresponding voltage is output from an A / D conversion part. It is an example of arrangement | positioning of the coil and RF tag in an insertion part. It is a figure which shows the timing which the corresponding voltage is output from an A / D conversion part. It is the main flowchart which showed the process regarding insertion shape calculation. It is a subroutine showing processing related to insertion shape calculation. It is an example of the synthesized image displayed on a monitor. It is a whole block diagram which shows the internal structure of the endoscope system in 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external view of an endoscope system 1 according to the present embodiment. The endoscope system 1 includes an endoscope apparatus (also called a scope) 10, an insertion shape observation apparatus 200, an image processing apparatus 300, a light source apparatus 400, and a monitor 500. The insertion shape observation device 200 and the video processing device 300 are collectively referred to as a processor.

The endoscope system 1 is a system in which an endoscope apparatus 10 is operated by a doctor to obtain an image in a body cavity of a patient as a subject, and an endoscopic examination or the like is performed. In FIG. 1 and the following, a case where a lower endoscopy is performed using a lower gastrointestinal endoscopic apparatus will be described as an example.

The endoscope apparatus 10 includes an operation unit 20 operated by a doctor and an insertion unit 30 provided with an imaging unit 74 (see FIG. 2) for imaging a body cavity at a distal end. The insertion unit 30 is provided with a plurality of coils and detection devices for calculating the insertion shape. Details will be described later.

The insertion shape observation apparatus 200 is for obtaining the insertion shape of the insertion portion 30 in the body cavity. The insertion shape observation apparatus 200 calculates the insertion shape by measuring a change in the distance between the coil and the detection device due to the deformation of the insertion unit 30. The insertion shape observation apparatus 200 generates an insertion shape image based on the calculated insertion shape. The insertion shape observation apparatus 200 includes an oscillator or the like that outputs a coil drive signal. Details of the calculation of the insertion shape will be described later.

The video processing device 300 performs various processes on the image signal acquired by the imaging unit 74 provided at the distal end of the insertion unit 30, and outputs endoscopic image data that is a video image in the body cavity. The light source device 400 is a light source that generates irradiation light that irradiates a body cavity for imaging. The monitor 500 displays an endoscopic image output from the video processing device 300 and an insertion shape image generated by the insertion shape observation device 200.

<First Embodiment>
FIG. 2 is an overall block diagram showing an internal configuration of the endoscope system 1. It is a block diagram for mainly explaining insertion shape observation processing.

The insertion unit 30 has an imaging unit 74 at the tip. The imaging unit 74 includes a lens unit 70 and an imaging element 72 that photoelectrically converts an optical image and outputs an image signal. The imaging device 72 is, for example, a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor).

The insertion unit 30 includes a coil 40 and an RF (radio frequency) tag 50 for observing the insertion shape. In 1st Embodiment, the example which applies RF tag 50 as a detection device is shown. The detection device may be an element that detects an electromagnetic wave or a magnetic field radiated from the coil 40 and outputs a corresponding signal. The RF tag is also referred to as an RFID tag, and includes a control circuit and a memory. The RF tag generates electric power from an external electromagnetic wave and radiates a predetermined response signal.

The coil 40 receives the response signal radiated from the RF tag 50 in response to the radiated electromagnetic wave by radiating the electromagnetic wave when the coil driving signal is applied. The insertion unit 30 is provided with a transmission line 60 for transmitting a signal between the coil 40 and the insertion shape observation device 200. The insertion section 30 is provided with a plurality of coils 40 and RF tags 50 and a plurality of transmission lines 60 at predetermined intervals at positions near the surface along the insertion direction (longitudinal direction). In addition, the insertion unit 30 is provided with a light guide that guides illumination light supplied from the light source device 400 to the inside.

The insertion shape observation apparatus 200 includes a CPU 210, a memory 230, a communication IF 240, an oscillator 250, an A / D conversion unit 260, and a video signal output unit 270. The CPU 210 controls the entire processing of the insertion shape observation apparatus 200 in an integrated manner. The CPU 210 reads the control program stored in the memory 230 and executes each control process according to the control program. The memory 230 stores control programs and data.

The communication IF 240 communicates control data between the insertion shape observation device 200 and the video processing device 300, and receives image data (endoscopic image data) output from the video processing device 300 to the insertion shape observation device 200. . The oscillator 250 outputs a coil drive signal to the coil 40 in accordance with an instruction from the CPU 210. The A / D converter 260 samples a voltage waveform of a signal input / output to / from the oscillator 250 and outputs a digital signal.

The coil drive signal output from the oscillator 250 is transmitted to the coil 40 through the transmission line 60 and applied. The coil 40 radiates an electromagnetic wave corresponding to the applied coil driving signal. The signal radiated from the coil 40 is detected by the RF tag 50. The RF tag 50 receives the emitted signal and emits a corresponding response signal. The oscillator 250 may output a pulse signal, an FM (modulation) signal, or the like as the coil drive signal.

The coil 40 receives a response signal radiated from the RF tag 50. The response signal received by the coil 40 returns to the oscillator 250 through the transmission line 60 (same path as the coil drive signal). The A / D converter 260 samples the voltage waveform of the coil drive signal output from the oscillator 250 and outputs the corresponding voltage to the CPU 210. The A / D conversion unit 260 samples the voltage waveform of the response signal received by the coil 40 and outputs a corresponding voltage to the CPU 210.

The CPU 210 measures the time difference between the voltage corresponding to the coil drive signal output from the A / D converter 260 and the voltage corresponding to the response signal output from the A / D converter 260, and determines the coil 40 from the time difference. The distance between the RF tags 50 is calculated. The CPU 210 sets the adjacent coils 40 and RF tags 50 as one set for the plurality of coils 40 and RF tags 50 provided along the insertion direction of the insertion unit 30, acquires the distance of each set, and obtains the distance of each set. An insertion shape is calculated from the above, and an insertion shape image is generated. A specific example of the combined arrangement of the coil 40 and the RF tag 50 will be described later with reference to FIG.

A plurality of RF tags exist in the vicinity of one coil 40, and the plurality of RF tags respond by electromagnetic waves from one coil 40. The one coil 40 simultaneously receives response signals from the plurality of RF tags. There is a possibility of receiving. It is necessary to exclude other than the response signal of the specific RF tag 50. Therefore, for example, in order to prevent response signals from being output from RF tags 50 other than desired, the resonance frequency of the antenna portion of each RF tag 50 may be changed, or a filter may be provided. Good.

Further, the response signal of the desired RF tag 50 may be identified from the plurality of response signals by the ID of the RF tag 50 included in the response signal from the RF tag 50. The means for identifying the response signal of the desired RF tag 50 by the ID information may be provided in the A / D converter 260 or may be performed by the CPU 210.

The video signal output unit 270 is configured by a video encoder or the like, and receives image data (image data obtained by synthesizing endoscope image data with insertion shape image data) generated by the CPU 210 as a predetermined video signal (for example, HDMI or RGB). ) And output.

The video processing apparatus 300 includes a CPU 310, a memory 330, a communication IF 340, and a signal processing unit 350. The CPU 310 controls the entire processing of the video processing device 300 in an integrated manner. The CPU 310 reads the control program stored in the memory 330 and executes each control process according to the control program.

The memory 330 stores control programs and data. The communication IF 340 communicates image data (endoscopic image data), control data, and the like between the video processing device 300 and the insertion shape observation device 200. The signal processing unit 350 performs various necessary image signal processing such as A / D, AGC (Automatic Gain Control), and CDS (Correlated Double Sampling) on the image signal acquired by the imaging unit 74 of the insertion unit 30.

The light source device 400 includes a light emitting unit 410 made of a xenon lamp or the like. A light guide 420 made of glass fiber or the like is connected to the light source device 400.

3A and 3B are diagrams showing the transmission line 60, the coil 40, and the like provided in the insertion portion 30. FIG. FIG. 3A is a cross-sectional view of the insertion portion 30 taken along a plane perpendicular to the insertion direction (longitudinal direction). FIG. 3B is a cross-sectional view of the insertion portion 30 inserted into the body cavity along a plane parallel to the insertion direction (longitudinal direction). The left side of FIG. 3B is the body cavity, and the right side is the direction in which the insertion shape observation apparatus 200 is located.

As shown in FIG. 3A and FIG. 3B, a signal cable (not shown) to the light guide 420 and the imaging unit 74 is provided inside the insertion unit 30. A transmission line 60 is provided in a portion near the outer surface of the insertion portion 30. Here, an example in which two sets of transmission lines 60a and 60c are disposed to face each other by 180 ° as the transmission line 60 (see FIG. 3A). The transmission line 60a is connected to the coil 40a, and the transmission line 60c is connected to the coil 40c.

FIG. 4 is a diagram illustrating a type of wiring example of the transmission line 60 with respect to the coil 40. FIG. 4A is a wiring diagram of a type in which one set of transmission line 60 is wired to each coil 40. This is an example corresponding to the transmission lines 60a and 60c shown in FIG. Transmission lines 60 corresponding to the number of coils 40 are connected to the oscillator 250. The oscillator 250 outputs a coil drive signal to the transmission line 60 corresponding to the coil 40 to be driven.

FIG. 4B is a type of wiring diagram in which a common transmission line 60 is wired to each coil 40. In this case, a changeover switch 64 controlled by the CPU 210 is provided between the common transmission line 60 and each coil 40 so that a coil drive signal is applied only to the specific coil 40.

FIG. 5 is a functional block diagram for explaining a control process by the CPU 210 of the insertion shape observation apparatus 200. The CPU 210 includes a coil drive control unit 212, an insertion shape calculation unit 214, an insertion shape image generation unit 216, a superimposition unit 218, and an image processing unit 220. The coil drive control unit 212, the insertion shape calculation unit 214, the insertion shape image generation unit 216, the superimposition unit 218, and the image processing unit 220 are realized by the CPU 210 that reads the control program stored in the memory 230.

The coil drive control unit 212 controls the oscillator 250 so as to apply a coil drive signal to the coil 40. The coil drive control unit 212 controls the oscillator 250 so that a coil drive signal is applied to each coil 40 in a predetermined order.

The insertion shape calculation unit 214 measures the distance between the coil 40 and the RF tag 50 from the time difference between the timing at which the coil drive signal is output to the coil 40 and the timing at which the response signal from the RF tag 50 is received. The insertion shape is calculated from

The insertion part shape calculation process will be briefly described. The insertion shape calculation unit 214 calculates the [coil 40 and RF from the voltage based on the coil drive signal of the oscillator 250 output from the A / D conversion unit 260 and the voltage based on the response signal output from the A / D conversion unit 260. The time difference in one set of tags 50] is measured and this is performed for each set.

The insertion shape calculation unit 214 measures the distance between the [coil 40 and the RF tag 50] in each set from the time difference measured in each set of the [coil 40 and RF tag 50]. Then, the insertion shape calculation unit 214 calculates the insertion shape with reference to the pattern table 232 of the memory 230 based on the coordinate position and distance of each set on the insertion unit 30. The pattern table 232 is a table in which the relationship between the pattern of the distance matrix and the actual (actually measured) bending amount / bending direction is described in advance. The pattern table 232 is also called actually measured distance matrix data.

The insertion shape image generation unit 216 generates insertion shape image data obtained by imaging the insertion shape based on the calculated insertion shape.

The image processing unit 220 performs predetermined image processing on the endoscope image data output from the video processing device 300. The superimposing unit 218 superimposes the insertion shape image data on the endoscope image data that has been subjected to the predetermined image processing by the image processing unit 220 to create a composite image. The composite image is encoded and output from the video signal output unit 270 and displayed on the monitor 500. FIG. 12 is an example of a composite image displayed on the monitor 500. The composite image E1 includes an endoscope image E2 and an insertion shape image E3.

Next, the details of the insertion portion shape calculation process will be described with reference to FIGS. FIG. 6 is a schematic diagram illustrating a state in which a response signal is returned when a coil drive signal is output from the oscillator 250.

A coil drive signal is output from the oscillator 250, applied to the coil 40 via the transmission line 60, and electromagnetic waves are radiated from the coil 40. The RF tag 50 arranged at a position away from the coil 40 by the distance D returns a response signal to the coil 40. The coil 40 receives the response signal, and the received response signal returns to the oscillator 250 via the transmission line 60. The time until the response signal returns to the oscillator 250 is determined by the distance D between the coil 40 and the RF tag 50 when the signal transmission delay amount tl by the transmission line 60 is constant.

FIG. 7 is a diagram illustrating the timing at which the corresponding voltage is output from the A / D converter 260. After the voltage corresponding to the coil drive signal is output from the A / D converter 260, the voltage corresponding to the response signal is output with a delay of dt time. The time difference dt changes according to the distance between the coil 40 and the RF tag 50. As described above, the time difference dt is measured by the insertion shape calculation unit 214.

Next, a method for calculating the distance D from the time difference dt will be described. FIG. 8 shows an arrangement example of the coil 40 and the RF tag 50 in the insertion portion 30. The arrangement example of the coil 40 and the RF tag 50 in FIG. 8 is an example for explaining a method of calculating the distance D.

In the example illustrated in FIG. 8, a set of RF tags including two RF tags 50 (also referred to as a b / d type) and a coil 40 including two coils 40 are provided between the distal end of the insertion unit 30 and the operation unit 20. Groups (also referred to as a / c type) are alternately arranged at predetermined intervals. Specifically, [RF tag 50-1b and RF tag 50-1d], [coil 40-1a and coil 40-1c], [RF tag 50-2b and RF tag 50-2d in this order from the distal end of the insertion section 30. ], [Coil 40-2a and Coil 40-2c] are arranged.

In addition, a set of RF tags 50 are arranged with a predetermined angle (90 ° in this example) with respect to a pair of adjacent coils 40 in the polar coordinate system φ shown in the figure. Specifically, the RF tag 50-1b, which is a set of coils closest to the distal end of the endoscope insertion portion, is arranged at a position of φ = 90 °, and the RF tag 50-1d is arranged at a position of φ = 270 °. Subsequently, the coil 40-1a is arranged at φ = 0 °, and the coil 40-1c is arranged at φ = 180 °. Similarly, the RF tag 50-2b is arranged at a position of φ = 90 °, and the RF tag 50-2d is arranged at a position of φ = 270 °. The coils 40 and the RF tags 50 having the same alphabet (a, b, c, d) at the end of the code indicate that the phases are the same.

Further, the coil 40 is a connection disposed on the transmission line 60 corresponding to the alphabet at the end of the code. That is, the coils 40-1a and 40-2a are connected to the transmission line 60a (not shown in FIG. 8), and the coils 40-1c and 40-2c are connected to the transmission line 60c (not shown in FIG. 8). . Therefore, the coils 40-1a, coils 40-2a,... And the transmission line 60a are configured as described with reference to FIG.

Hereinafter, an example of calculating a distance matrix by using a section consisting of [two adjacent RF tags 50 and two coils 40] as a section (Sc) (see FIG. 8) and using this section as a unit will be described. As shown in FIG. 8, an example is described in which the combination of [RF tag 50-1b and RF tag 50-1d] and [coil 40-1a and coil 40-1c] is Sc1, and the distance matrix is obtained from Sc1. .

First, the time difference between [coil 40-1a and RF tag 50-1b] is measured. A coil drive signal is applied to the coil 40-1a from the oscillator 250 via the transmission line 60 (a), and electromagnetic waves are radiated. A response signal is emitted from the RF tag 50-1b that has detected the electromagnetic wave. The response signal radiated from the RF tag 50-1b is detected by the coil 40-1a and received by the A / D converter 260.

The A / D converter 260 outputs a voltage corresponding to the coil drive signal to the coil 40-1a. The A / D converter 260 receives response signals from the plurality of RF tags 50. The response signals from the RF tag 50-1b are obtained by the above-described means (for example, identification by RF tag ID information). The voltage corresponding to is output. The insertion shape calculation unit 214 measures the time difference between the voltage based on the coil drive signal to the coil 40-1a and the voltage based on the response signal from the RF tag 50-1b received by the coil 40-1a.

Next, the time difference between [coil 40-1a and RF tag 50-1d] is measured. A coil drive signal is applied to the coil 40-1a. The A / D converter 260 outputs a voltage based on the coil drive signal to the coil 40-1a. Further, the A / D converter 260 outputs a voltage based on a response signal from the RF tag 50-1d. The insertion shape calculation unit 214 measures the time difference between the voltage based on the coil drive signal to the coil 40-1a and the voltage based on the response signal from the RF tag 50-1d received by the coil 40-1a.

Similarly, the time difference between [coil 40-1c and RF tag 50-1b] and the time difference between [coil 40-1c and RF tag 50-1d] are measured.

FIG. 9 is a diagram illustrating a timing at which a part of the voltages Sc1 and Sc2 is output from the A / D converter 260 to the CPU 210. [Coil 40-1a and RF tag 50-1b], [Coil 40-1a and RF tag 50-1d], [Coil 40-1c and RF tag 50-1b], [Coil 40-1c and RF tag 50-1d] ], T1a-1b, t1a-1d, and t1c-1b. Shown as t1c-1d.

When the distance between the [coil 40-1a and the RF tag 50-1b] is D1a-1b, D1a-1b = (t1a-1b-tl) × 0.5c. c is a signal propagation speed, and tl is a delay due to the length of the transmission line 60.

The distance matrix between the coil 40 and the RF tag 50 in Sc1 is represented by the following formula (1).

When the insertion portion 30 is curved, the positional relationship between the adjacent four coils 40 and the RF tag 50 changes, so that the value of the resultant distance matrix changes. For example, in the polar coordinate system of FIG. 8, when the insertion portion is curved in the + θ direction, the RF tag 50-1b and the RF tag 50-1d are close to each other in the distance of the coil 40-1a, and D1a-1b and D1a-1d are Get smaller.

In addition, if it is curved in the + φ direction at this time, the RF tag 50-1d is closer to the coil 40-1a than the RF tag 50-1b, so that D1a-1b <D1a-1d.

Then, how much the distance matrix of Equation (1) changes in accordance with the values of θ and φ is obtained by actual measurement or the like in advance and referred to as a table, and is correlated with the actually obtained distance matrix. The number is obtained and it is determined that the highest degree of correlation is the current bending amount / bending direction of the endoscope insertion portion.

Then, this shape can be calculated for the entire length of the insertion portion 30, and the three-dimensional shape of the entire insertion portion 30 can be calculated. As shown in FIG. 8, Sc1, Sc2, Sc3,... Sc (n−1) in order from the tip, and by combining adjacent sets (sections) of the coil 40 and the RF tag 50, the insertion portion 30 The entire three-dimensional shape can be calculated.

As described above, in the endoscope system 1 according to the present embodiment, the insertion shape of the endoscope insertion portion can be obtained three-dimensionally from the distance between each coil 40 and the RF tag 50.

Next, a processing procedure related to the insertion shape calculation according to the present embodiment will be described. 10 and 11 are flowcharts for explaining the procedure for calculating the insertion shape according to this embodiment. FIG. 10 is a main flowchart. FIG. 11 is a subroutine. The processes in FIGS. 10 and 11 are mainly executed by the CPU 210 of the insertion shape observation apparatus 200.

In FIG. 10, the insertion shape calculation unit 214 sets the section (Sc) number k to 1 as an initialization process (step S10). The coil drive control unit 212 performs coil drive control (step S12).

<Go to the subroutine in FIG. In this process, steps S100 to S112 are executed for each combination of the coil 40 and the RF tag 50 belonging to the section k. That is, in the example of Sc1 in FIG. 8, [coil 40-1a and RF tag 50-1b], [coil 40-1a and RF tag 50-1d], [coil 40-1c and RF tag 50 belonging to Sc1. −1b] and [Coil 40-1c and RF tag 50-1d], Steps S100 to S112 are respectively executed.

The coil drive control unit 212 instructs the oscillator 250 to output a coil drive signal. The oscillator 250 outputs a coil drive signal to a predetermined coil of the section k (step S100). For example, the oscillator 250 outputs a coil driving signal to the coil 40-1a.

The A / D conversion unit 260 detects the coil drive signal output from the oscillator 250 (step S102), and outputs a corresponding voltage to the insertion shape calculation unit 214.

The coil 40 radiates electromagnetic waves by a coil drive signal (step S104). The RF tag 50 detects the electromagnetic wave radiated by the coil drive signal (step S106). The RF tag 50 outputs (radiates) a response signal according to the detected electromagnetic wave (step S108).

The coil 40 receives the response signal radiated from the RF tag 50 (step S110). The A / D conversion unit 260 detects the response signal via the transmission line 60, samples the response signal, and outputs a corresponding voltage to the insertion shape calculation unit 214 (step S112). For example, the A / D converter 260 outputs the corresponding voltage based on the response signal of the RF tag 50-1d to the insertion shape calculator 214. As described above, this processing is performed for the combination of the other coil 40 and the RF tag 50 belonging to the section k. When the processing is completed, the process proceeds to step S14 in FIG.

The insertion shape calculation unit 214 receives the output timing and the response signal at which the coil driving voltage is output based on the voltage corresponding to the coil driving signal output from the A / D conversion unit 260 and the voltage corresponding to the response signal. A time difference from the timing is calculated (step S14).

The insertion shape calculation unit 214 reads the voltage waveform from the A / D conversion unit 260, and calculates the time difference from when the oscillator 250 outputs the coil drive signal until the coil 40 receives the response signal from the RF tag 50. To do. In the example of FIG. 8, four time differences (t1a-1b, t1a-1d, t1c-1b, t1c-1d) are calculated for one section.

The insertion shape calculation unit 214 analyzes the time difference and generates a distance matrix (formula (1)) between the coil 40 and the RF tag 50 (step S16).

The insertion shape calculation unit 214 performs matching between the generated distance matrix and the pattern table 232 stored in advance in the memory 230, and calculates the bending amount and the bending direction in the corresponding section (step S18).

The insertion shape calculation unit 214 increments the section number k by 1 (step S20). The insertion shape calculation unit 214 determines whether the section number k is the last (step S22). The insertion shape calculation unit 214 determines that the section number k is not the last (No in step S22), returns to step S12, moves to the next numbered section, and performs analysis in the same procedure.

If the insertion shape calculation unit 214 determines that the section number k is the last (Yes in step S22), the insertion shape calculation unit 214 has calculated the insertion shape of the entire insertion unit 30, so the insertion shape calculation unit 214 The insertion shape data of each section is notified to the insertion shape image generation unit 216. The insertion shape image generation unit 216 generates corresponding insertion shape image data based on the insertion shape data of each section (step S24).

The superimposing unit 218 superimposes the generated image data of the insertion shape on the endoscope image data, and generates composite image data (step S26). The video signal output unit 270 outputs the composite image to the monitor 500. As shown in FIG. 12, the monitor 500 displays a composite image E1 obtained by combining the endoscope image E2 and the insertion shape image E3.

As described above, according to the endoscope system 1 according to the present embodiment, the coil drive signal output from the oscillator 250 is transmitted through the transmission line 60 provided along the insertion portion 30 of the endoscope apparatus 10. To do. The transmitted coil drive signal is radiated in the coil 40, and the radiated electromagnetic wave is detected by the RF tag 50. The RF tag 50 detects an electromagnetic wave and emits a corresponding response signal. The coil 40 detects a response signal radiated from the RF tag 50. The response signal detected by the coil 40 returns to the oscillator 250 through the transmission line 60 again.

The A / D converter 260 samples the input / output voltage waveform of the oscillator 250. The insertion shape calculation unit 214 obtains the distance matrix between each coil 40 and the RF tag 50 shown by the above formula (1) based on the time difference between the corresponding voltages. The insertion shape calculation unit 214 performs matching between the obtained distance matrix and the pattern table 232 of the distance matrix corresponding to the bending amount / bending direction stored in the memory 230 to obtain the bending amount / bending direction in the corresponding section. .

The insertion shape calculation unit 214 repeats this for the number of combinations (number of sections) of the coil 40 and the RF tag 50 provided in the insertion unit 30, calculates the bending amount and the bending direction of all the sections, and The insertion shape is calculated. Thereby, in this embodiment, it is possible to calculate the shape of the insertion portion 30 in the endoscope apparatus 10 with a simpler configuration without requiring a large apparatus such as an antenna unit.

Second Embodiment
In the first embodiment, the example in which the RF tag 50 is applied to the detection device has been described. The detection device is not limited to the RF tag, and for example, a coil can be applied. In the second embodiment, an example in which a coil is applied to a detection device will be described.

FIG. 13 is an overall block diagram showing an internal configuration of the endoscope system 1 in the second embodiment. The external view of the endoscope system 1 of the second embodiment is the same as FIG. In FIG. 13, only the insertion part 30b and the insertion shape observation apparatus 200b which differ from 1st Embodiment are shown.

The insertion portion 30b is provided with a coil 40, a transmission line 60, a sense coil 42 (also referred to as a second coil) that is a detection device, and a transmission line 62. Since the coil 40 and the transmission line 60 are the same as those in the first embodiment, description thereof is omitted.

The sense coil 42 is a detection means that replaces the RF tag 50. Each of the sense coils 42 is provided with a transmission line 62, and the transmission line 62 is connected to the insertion shape observation device 200b.

The insertion shape observation apparatus 200b includes a CPU 210b, a memory 230, a communication IF 240, an oscillator 250, an A / D conversion unit 260b, and a video signal output unit 270. Since the memory 230, the communication IF 240, the oscillator 250, and the video signal output unit 270 are the same as those in the first embodiment, description thereof is omitted. The oscillator 250 applies a coil drive signal to the predetermined coil 40.

The A / D converter 260b detects and samples a coil drive signal applied to the coil 40, and outputs a corresponding voltage to the CPU 210b. Furthermore, the A / D converter 260b detects the induced current generated in the sense coil 42 as a response signal via the transmission line 62, samples it, and outputs a corresponding voltage to the CPU 210b.

The CPU 210b calculates the time difference between the coil drive signal output from the A / D converter 260b and the response signal. Hereinafter, the process in which the CPU 210b calculates the insertion shape and generates the insertion shape image is the same as that in the first embodiment, and is therefore omitted.

With the above configuration, a coil drive signal is applied to the coil 40 from the oscillator 250, and an induced current is generated in the sense coil 42 by the magnetic field generated by the coil 40. The induced current generated in the sense coil 42 is input as a response signal to the A / D converter 260b through the transmission line 62. The A / D converter 260b outputs voltages corresponding to the coil drive signal and the response signal to the CPU 210b. As in the first embodiment, the CPU 210b calculates an insertion shape from the time difference, generates an insertion shape image, and outputs the composite image to the monitor 500. *

The above embodiments eliminate the need for an antenna system, and can provide an endoscope system that acquires the insertion shape of the endoscope apparatus insertion portion with a compact configuration.

In each of the above embodiments, the case where the oscillator 250 is installed in the insertion shape observation apparatus 200 of the endoscope system 1 is described as an example. However, in order to realize the method of calculating the insertion shape of the insertion unit 30 of the endoscope apparatus 10 according to the present embodiment, the configuration is not limited to such a configuration. For example, the function included in the insertion shape observation apparatus 200 such as the oscillator 250 and the CPU 210 may be installed in the operation unit 20 of the endoscope apparatus 10. In this case, particularly in a portable endoscope system, it can be said that the utility is high in that all functions can be mounted only by the endoscope apparatus.

Furthermore, in each of the above embodiments, the insertion shape of the insertion portion is calculated from the signal transmission time between the coil 40 and the detection device, but the calculation method is not limited thereto. Instead of obtaining the distance between the coil 40 and the detection device from the signal transmission speed, it is also possible to obtain the distance from the signal reception sensitivity (such as the transmission coefficient between the coil 40 and the detection device) to calculate the insertion shape. . The coil 40 is not limited to the shape of the coil, and the same effect can be obtained as long as an electromagnetic field is formed around the coil 40.

In the present embodiment, the insertion shape observation device 200, the video processing device 300, and the light source device 400 have been described as separate devices. However, the insertion shape observation device 200, the video processing device 300, and the light source device 400 may be It may be configured by combining two or more.

Further, the image signal transmitted between the endoscope apparatus 10 and the video processing apparatus 300 is not limited to an electrical signal, and may be a signal that is transmitted / received by modulating the electrical signal into light, for example. Further, the image signal between the endoscope apparatus 10 and the video processing apparatus 300 is not limited to being transmitted by a wire, but may be transmitted by radio.

Further, the light source of the light source device 400 may use a laser light source. In addition, the configuration in which the light source is supplied by the light guide from the light source device 400 that is separate from the endoscope device 10 has been described. However, the present invention is not limited thereto, and for example, a semiconductor light source (at the distal end of the insertion portion 30 of the endoscope device 10) LED or laser) may be provided.

In the above description, the CPU 210 calculates the insertion shape. However, the present invention is not limited to such a configuration. For example, the calculation processing of the above-described insertion shape can be realized by an FPGA (field-programmable gate array) or the like. Further, part or all of the processing by the CPU 210 may be configured by hardware. Further, the oscillator 250 and the A / D converter 260 may be realized by software processing.

Note that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, all the constituent elements shown in the embodiments may be appropriately combined. Furthermore, constituent elements over different embodiments may be appropriately combined. It goes without saying that various modifications and applications are possible without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 1b Endoscope system 10 Endoscope apparatus 20 Operation part 30 30b Insertion part 40 40-1a 40-1c 40-2a 40-2c Coil 42 Sense coil 50 50-1b 50-1d 50-2b 50-2d RF tag 60 62 Transmission line
64 switches
70 Lens Unit 72 Image Sensor 74 Imager 200 Insert Shape Observation Device
210 210b CPU
212 Coil Drive Control Unit 214 Insertion Shape Calculation Unit 216 Insertion Shape Image Generation Unit 218 Superimposition Unit 220 Image Processing Unit 230 Memory 232 Pattern Table 240 Communication IF
250 Oscillator 260 262 A / D converter
270 Video signal output unit
300 Video processing device
310 CPU
330 Memory 340 Communication IF
350 Signal Processing Unit 400 Light Source Device 500 Monitor

Claims (10)

An endoscope system that inserts an insertion portion of an endoscope device into a subject and obtains a captured image in the subject,
An oscillator that outputs a coil drive signal;
A detection device that is provided in the insertion portion, detects an electromagnetic wave radiated based on the coil drive signal, and outputs a response signal;
A coil that is provided in the insertion portion and emits electromagnetic waves to the detection device by an applied coil drive signal;
A transmission line provided in the insertion portion, for transmitting a signal between the oscillator and the coil;
A distance between the coil and the detection device is obtained from an output timing at which a coil driving signal is output from the oscillator and a reception timing at which a response signal is received from the detection device, and the insertion portion is determined based on the distance. An insertion shape calculation unit for calculating the insertion shape;
An endoscope system comprising: The endoscope system according to claim 1, wherein a plurality of sets of the coil and the detection device are provided in an insertion direction of the insertion portion. The detection device is an RF tag,
2. The endoscope according to claim 1, wherein the reception timing of receiving a response signal from the detection device is a timing at which the coil receives a response signal radiated from the RF tag that is the detection device. Mirror system. The endoscope system according to claim 1, wherein the detection device is a second coil that generates an induced current by detecting a magnetic field generated in the coil based on the applied coil driving signal. The insertion shape calculation unit includes the coil and the detection device as a set, distance matrix data derived by calculating a plurality of distances of the plurality of sets, and the coil and the detection device in a state where the insertion unit is curved. The endoscope system according to claim 2, wherein a curved shape of the insertion portion is obtained based on a correlation with measured distance matrix data obtained in advance by actually measuring the distance. The insertion shape calculation unit calculates the insertion shape from the obtained distance between the coil and the detection device based on a pattern table in which the relationship between the insertion shape and the distance between the coil and the detection device is described in advance. The endoscope system according to claim 1, wherein: The insertion portion has a substantially circular cross section and is formed in an elongated shape along the insertion direction.
The endoscope system according to claim 1, wherein the insertion unit provides the detection device at a position away from the coil by a predetermined angle along a circumferential direction of a substantially circular cross section. An insertion part to be inserted into the subject;
A coil that is provided in the insertion portion and emits an electromagnetic wave according to an applied coil drive signal;
A detection device that is provided in the insertion portion, detects an electromagnetic wave radiated based on the coil drive signal, and outputs a response signal;
A transmission line that is provided along the insertion portion and transmits a coil drive signal output from an oscillator to the coil;
An endoscope apparatus comprising: An oscillator that outputs a coil drive signal for driving a coil provided in the endoscope insertion portion;
The coil outputs an output timing at which a coil drive signal is output from the oscillator, and a response signal provided in the endoscope insertion portion and output from a detection device that detects an electromagnetic wave radiated from the coil by the coil drive signal. An insertion shape observation comprising: an insertion shape calculation unit that obtains a distance between the coil and the detection device from a reception timing to receive and calculates an insertion shape of the insertion unit based on the distance apparatus. In an insertion shape calculation method in an endoscope system in which an insertion unit of an endoscope apparatus is inserted into a subject and a captured image in the subject is acquired.
Apply the coil drive signal from the oscillator to the coil provided in the insertion part,
A response signal output from a detection device that is provided in the insertion portion and detects an electromagnetic wave radiated from the coil based on the coil drive signal is received.
A distance between the coil and the detection device is obtained from an output timing at which a coil drive signal is output from the oscillator and a reception timing at which a response signal output from the detection device is received, and the insertion is performed based on the distance. An insertion shape calculation method comprising calculating an insertion shape of a part.

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