JPH10286221A - Shape detecting device for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shape detecting device for an endoscope by which the shape of an endoscope inserted part can be easily detected without enlarging the outside diameter of the endoscope inserting part. SOLUTION: A controller 16 is provided with a signal processing circuit 31, a pulse generating circuit 32, laser devices 33a and 33b, beam splitters 34a and 34b, APDs 35a and 35b, amplifiers 36a and 36b, and a connector 18 to which an optical fiber cable 15 is connected. The pulse beams irradiated from the laser devices 33a, 33b pass through the beam splitters 34a, 34b and are optically transmitted and incident on the end surfaces of optical fibers 21, 22. Backwardly scattered light rays generated by the optical fibers 21, 22 are incident on the APDs 35a and 35b, and the electric signals amplified by amplifiers 36a, 36b are arrthmetically processed by the signal processing circuit 31, so that the bending angle and bending direction of the inserted part can be obtained, and also the image signal of the curved shape of the inserted part is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope shape detecting device for detecting the shape of an endoscope insertion portion in a test portion.

[0002]

2. Description of the Related Art In recent years, endoscopes have been widely used in the medical and industrial fields. In particular, in an endoscope having a flexible insertion portion used in the medical field, by inserting this insertion portion into the bent body cavity from the mouth or anus,
It is possible to diagnose internal organs deep in the body cavity without making an incision, and to perform a medical treatment such as excising a polyp or the like by inserting a treatment tool into a conduit channel provided in the endoscope as needed.

For example, when an endoscope is inserted from the anal side to examine the inside of the lower gastrointestinal tract, some skill is required to smoothly insert the insertion portion into a bent body cavity. That is,
When performing the insertion operation of the endoscope, it is necessary to smoothly perform an operation such as bending a bending portion provided in the insertion portion in accordance with the bending in the body cavity, and insert the endoscope. However, it is convenient to be able to know the current curved state of the endoscope insertion section, such as where in the body cavity it is located.

Therefore, an X-ray opaque portion is formed in the insertion portion,
By irradiating X-rays, it has been considered to detect an X-ray opaque portion and observe the distal end position of the insertion portion and the curved state of the insertion portion.

However, an apparatus for irradiating X-rays is large. That is, in order to provide a device for irradiating X-rays in the examination room, the examination room must be sufficiently large. In addition, since the operator must perform an operation of irradiating X-rays in addition to the operation of the endoscope at the time of the endoscopic examination, the burden on the operator increases, and the operator frequently performs X-rays. When the radiation is applied, the radiation dose increases, which may be harmful not only to the patient but also to the operator.

[0006] For this reason, Japanese Patent Application Laid-Open No. Hei 5-91972 discloses a curved display device for displaying a curved state of an insertion portion of an endoscope. This curved display device has a structure in which a first optical fiber and a second optical fiber are arranged along a flexible member, and when light from a light source is introduced from each entrance of the first optical fiber and the second optical fiber. , The introduced light is configured to be converted into an electric signal by a photodetector at an exit of the first optical fiber and the second optical fiber, and the first optical fiber is configured by a plurality of optical fiber pairs; Further, each optical fiber pair is constituted by two optical fiber elements, and the optical fiber elements are formed with connecting portions so as to be at different positions in different pairs and to be substantially at the same position in the same pair, The optical fiber pair is such that each connecting portion provided on the optical fiber element has two
Are arranged so as to form an opening angle corresponding to the axis inclination angle of the direction, and the arithmetic unit calculates the axis inclination angle of the optical fiber element at each of the connection parts by using the electric signal, whereby The bending state of the flexible member is configured to be displayed on a monitor.

[0007]

However, in the curved display device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Hei 5-91972, for example, when trying to obtain the bending information of n places of the insertion portion, n pairs of bending information are required. Since it is necessary to provide optical fibers and to reciprocate each optical fiber, at least (4Xn) optical fibers must be provided in the endoscope insertion portion.

Also, in order to obtain the bending state of the insertion portion of the endoscope with higher accuracy, it is necessary to obtain bending information at more points. Then, there is a problem that the number of optical fibers increases with this, and the outer diameter of the endoscope insertion portion becomes large.

[0009] The present invention has been made in view of the above circumstances, without increasing the outer diameter of the endoscope insertion portion,
An object of the present invention is to provide an endoscope shape detection device capable of easily detecting the shape of an endoscope insertion section.

[0010]

An endoscope shape detecting apparatus according to the present invention comprises an optical fiber provided with a plurality of bend angle detecting portions, and an endoscope having the optical fibers arranged along the longitudinal direction in the endoscope inserting portion. Mirror, pulsed light irradiation means for supplying pulsed light to the optical fiber, and pulsed light from the pulsed light irradiation means incident on the optical fiber,
A light detecting means for detecting backward scattered light generated at an arbitrary position of the optical fiber, and a bending direction and a bending angle in a bending angle detecting unit provided on the optical fiber from the intensity of the backward scattered light detected by the light detecting means. Signal processing means for performing arithmetic processing and generating the endoscope insertion section shape into a video signal.

[0011] According to this configuration, backward scattering light from an arbitrary position of the optical fiber with respect to the pulse light sent to the optical fiber provided in the insertion section of the endoscope is detected by the light detecting means, and the signal processing means. The bend angle and the bend direction in the bend angle detection unit are calculated from the intensity of the backward scattered light detected by the light detection means, and a video signal is generated.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 relate to a first embodiment of the present invention, FIG. 1 is an explanatory view showing a schematic configuration of an endoscope shape detecting device, FIG. 2 is a sectional view of an insertion portion of the endoscope, and FIG. FIG. 4 is an explanatory diagram illustrating a schematic configuration of an optical fiber disposed in the unit, FIG. 4 is a block diagram illustrating a configuration of a shape detection control device, FIG. 5 is a flowchart illustrating an operation of the shape detection control device,
FIG. 6 is a diagram illustrating a relationship between a bent state and light loss in the angle detection unit.

As shown in FIG. 1, an endoscope shape detecting apparatus 1 according to the present embodiment is inserted into a body cavity to observe and treat an operation part, and is used together with the endoscope 2 to perform body cavity detection. And a shape detection control device 3 for detecting the position of the endoscope insertion portion inserted therein and the curved shape of the endoscope insertion portion.

In the endoscope shape detecting apparatus 1 of the present embodiment, the endoscope 2 is inserted into a body cavity of a patient 5 lying on a bed 4a of an endoscopic examination bed 4, for example, from an anus. The part 7 is inserted.

A universal cable 9 extends from one side surface of the operation unit 8 of the endoscope 2, and the universal cable 9 is connected to a video processor 10. The video processor 10 includes a light source unit (not shown) for supplying illumination light for observation to the endoscope and an electric signal photoelectrically converted by an image pickup device such as a CCD provided at the end of the endoscope. A signal processing unit (not shown) for processing a video signal is built in.

The illumination light from the light source unit is transmitted to an illumination window provided on the distal end surface of the insertion unit 7 via a light guide inserted through the endoscope 2, and from this illumination window into the body cavity. Is irradiated. Then, the operative portion such as an organ in a body cavity irradiated by the illumination light is provided by an objective optical system attached to an observation window provided on the distal end surface of the insertion portion 7.
An image is formed on an imaging surface of an imaging element arranged on a focal plane of the objective optical system, and is photoelectrically converted into an electric signal. The electric signal photoelectrically converted by the image pickup device is transmitted to a signal processing unit in the video processor 10 via a signal line, generated as a standard video signal, and output to the color monitor 11.
As a result, an endoscopic image of the surgical site is displayed on the screen of the color monitor 11.

An optical fiber cable 15 connected to the shape detection control device 3 extends from the other side surface of the operation unit 8 of the endoscope 2. An optical fiber described later is inserted into the optical fiber cable 15. The shape detection control device 3 for detecting the position and the shape of the endoscope insertion portion includes a control device 16 and a monitor 17, which will be described later, and the base end of the optical fiber cable 15 is connected to the connection portion 18. It has a detachable configuration.

As shown in FIG. 2A, the first optical fiber 2 extending in the longitudinal direction is provided on the inner peripheral surface of the insertion portion 7 of the endoscope 2.
First and second optical fibers 22 are arranged. The optical fibers 21 and 22 are guided from the distal end of the insertion section to the operation section 8 through the inside of the insertion section 7, and
5 to the base end of the optical fiber cable 15.

As shown in FIG. 2B, the first optical fiber 21 and the second optical fiber 22 are arranged so as to be displaced by 90 degrees inside the insertion section 7. I have.

As shown in FIGS. 3A and 3B, the first optical fiber 21 disposed in the insertion section 7
Are provided with a plurality of bend angle detection units 25 at arbitrary intervals (for example, at equal intervals).

As shown in FIG. 3C, three optical fiber stoppers 26 are disposed inside the bend angle detector 25, and the first optical fiber is connected to the three optical fiber stoppers 26. By arranging the optical fiber 21 by hooking, the optical fiber 21 bends only in the vertical direction shown on the paper surface, and does not bend in the direction perpendicular to the paper surface.

That is, when an external force is applied to the first optical fiber 21 from above and below in the drawing, the first optical fiber 21 is bent in the bending angle detecting section 25 in the up and down direction, but is orthogonal to the drawing. When an external force is applied from the direction, the first optical fiber 21 does not bend in the bend angle detector 25.

The second optical fiber 22 is provided with a plurality of bend angle detectors 25 at arbitrary intervals as in the case of the first optical fiber 21 described above. Further, the bending angle detecting unit 25 provided on the first optical fiber 21 and the bending angle detecting unit 25 provided on the second optical fiber 22 are configured to be paired. For this reason, the angle detection unit 25 provided as a pair in the first optical fiber 21 and the second optical fiber 22.
Are arranged at substantially the same position in the insertion section 7 so as to detect the bending state of the optical fibers 21 and 22 in the bending angle detecting section 25 in the vertical and horizontal directions. That is, the bending directions of the first optical fiber 21 and the second optical fiber 22 disposed in the bending angle detecting section 25 are different from each other by 90 degrees.

As shown in FIG. 4, the shape detection control device 3
It comprises a control device 16 and a monitor 17 as display means. The control unit 16 includes a signal processing circuit 31 as a signal processing unit for generating a video signal, a pulse generation circuit 32 as a pulse generation unit, laser devices 33a and 33b as pulse light irradiation units, and a light directional coupling. Beam splitters 34a and 34b as means, avalanche photodiodes (hereinafter abbreviated as APDs) 35a and 35b as light detecting means, and amplifying devices such as operational amplifiers as amplifying means for amplifying signals detected by the APDs 35a and 35b. 36a, 36b and optical fiber cable 1
And a connecting portion 18 to which the base end of the connecting member 5 is detachably connected.

The laser devices 33a and 33b are provided with, for example, semiconductor lasers. The semiconductor lasers receive an output signal from the pulse generation circuit 32 and emit pulse light. The pulsed light emitted from the laser devices 33a and 33b passes through the beam splitters 34a and 34b and is provided in the first optical fiber 21 and the second optical fiber 21 disposed in the optical fiber cable 15 connected to the connection unit 18. Optical fiber 2
2 and propagates in the optical fibers 21 and 22 optically.

The first optical fiber 21 and the second
Each of the optical fibers 22 is preferably a single mode fiber, and the pulsed light incident on the optical fibers 21 and 22 propagates through the optical fibers, and the pulse light is transmitted from any position in the longitudinal direction of the first and second optical fibers 21 and 22. Generates scattered light in all directions. In the present invention, the required Rayleigh scattered light is rearward scattered light that is backward Rayleigh scattered light that propagates through the optical fibers 21 and 22 and returns to the pulse light incident end.
For this reason, in the present embodiment, it is not necessary to reciprocate the first optical fiber 21 and the second optical fiber 22 in the insertion portion, so that the first optical fiber 21 and the second optical fiber 22 are arranged one by one.

The APDs 35a and 35b are arranged at reflection positions of the beam splitters 34a and 34b.
The backward scattered light generated in the optical fiber cable 15 is reflected by the beam splitters 34a and 34b and
35a and 35b.

The amplifying devices 36a and 36b include an APD3
The electric signal obtained by the direction scattered light after being incident on 5a and 35b is amplified, and the amplified electric signal is output to the signal processing circuit 31.

The signal processing circuit 31 includes the amplifying device 36
In response to the electric signals from the a and b, the intensity of the backward scattered light is arithmetically processed, and the curved video signal of the insertion section 7 of the endoscope 2 is generated. The video signal generated by the signal processing circuit 31 is output to the monitor 17 connected to the signal processing circuit 31, and is displayed on the monitor screen by the insertion unit 7.
Is displayed.

The operation of the shape detection control device 3 configured as described above will be described with reference to FIG. As shown in step S1, the insertion section 7 of the endoscope 2 is inserted into the body cavity. At this time, the first optical fiber 21 and the second optical fiber 22 built in the optical fiber cable 15 are used.
Are supplied with pulsed light from the laser devices 33a and 33b.

When the insertion section 7 is inserted into the body cavity as shown in step S2, the insertion section 7 bends following the bent shape in the body cavity. Then, as shown in step S3, the first optical fiber 21 disposed in the insertion section 7
And the second optical fiber 22 also bends in accordance with the curvature of the insertion section 7. Therefore, as the first optical fiber 21 and the second optical fiber 22 bend as shown in step S4, bending loss occurs at the bent positions of the optical fibers 21 and 22, and the intensity of the backward scattered light changes. .

On the other hand, as shown in step S5, APD3
5a and 35b, the beam splitters 34a and 34b
The first optical fiber 21 that is reflected at one end and then enters
And the intensity of the backward scattered light from the second optical fiber 22 is measured. That is, as shown in step S6, an electric signal caused by the difference in the intensity of the backward scattered light is supplied to the signal processing circuit 31 to calculate the bending angle and the bending direction in the angle detector 25, and as shown in step S7. Then, a curved video signal of the insertion section 7 is generated. The video signal generated by the signal processing circuit 31 is transmitted to the monitor 1
7 and is drawn on the monitor screen as a curved shape of the endoscope insertion section.

As shown in FIGS. 6A to 6I, the endoscope 2
When the insertion portion 7 is inserted into the body cavity and bent upward, for example, on the paper surface, the first angle
The optical fiber 21 moves upward. The bending angle θ at this time is defined as θ = θ (+). In addition, FIG.
As shown in (III), when the insertion section 7 of the endoscope 2 is inserted into a body cavity and bent downward, for example, on the paper surface, the first optical fiber 21 in the bending angle detection section 25 moves downward. Moving. The bending angle θ at this time is defined as θ = θ (−). In addition, when the first optical fiber 21 is not bent at the bend angle detecting unit 25 as shown in FIGS. 6A to 6B, the bend angle θ is defined as θ = θ (0).

The light loss corresponding to each of the bending angles shown in FIGS. 6A to 6I is as shown in FIG. 6B. As shown in FIG. θ is θ =
When θ (+), the optical loss is A1 as shown in graph I, when θ = θ (0), the optical loss is A2 as shown in graph II, and when θ = θ (-), it is shown in graph III. As described above, the light loss is A3.

Here, from the intensity of the backward scattered light, the bending angle at an arbitrary position of the insertion section 7 of the endoscope 2, that is, each position of the first optical fiber 21 and the second optical fiber 22 (arbitrary bending angle) The principle of calculating the bending angle in the detection unit 25) will be briefly described.

First, the bending loss of the optical fiber will be described. When bending (microbending) occurs in an optical fiber, a part of light propagating in the optical fiber is emitted to the outside of the optical fiber, thereby causing an optical loss.
The amount of light loss generated at this time is proportional to the bending strength (bending angle). That is, if the amount of light loss at the position where the value of the bending angle is desired can be measured, the bending angle of the optical fiber can be calculated (detected).

For this reason, an optical time domain reflectometer (OTD)
(Abbreviated as R). The OTD
In the measurement method using R, pulse light is incident from one end surface of an optical fiber, and light returning to the pulse light incident end which is the one end surface on which the pulse light is incident (this light is backward scattered light). Is a measurement method for measuring Since the backward scattered light propagates in the optical fiber, the amount of light loss at each position of the optical fiber is reflected. Therefore, by measuring the intensity of the backward scattered light over the entire length of the optical fiber, the relative amount of loss at each position can be obtained. The measurement method using OTDR is a known technique, and is described in “Optical Measuring Instrument Guide”, edited by Toshiharu Tada and Tatsutoshi Honda, pp. 97-98.

That is, in the present invention, when the curved shape of the endoscope is obtained, it is performed by OTDR. For this reason, each of the optical fibers 21 and 22 in the arbitrary
Indirectly, to obtain the bending angle of each optical fiber 2
Optical fiber 2 at the position of each of angle detection units 25 of 1 and 22
The optical loss amounts of 1 and 22 are measured in advance. The OTDR
By obtaining the backward scattered light intensity, the light loss amount at that position can be converted from this value, and the bending angle of the optical fiber at each position is converted from this light loss amount. Here, the light loss amount at each position is a relative light loss amount at each position.

Next, by measuring the intensity of the backward scattered light with reference to FIG. 6, the bending direction and the bending angle in the bending angle detectors 25 provided on the first optical fiber 21 and the second optical fiber 22 are determined. The calculation method will be specifically described.

As shown in FIG. 6B, when light loss is obtained by measuring backward scattered light near a certain bending angle detector 25 of the first optical fiber 21, the first optical fiber 21 is connected to the optical fiber stopper 26. Therefore, even if the insertion section 7 is in a straight line state, a bending loss occurs in the bending angle detection section 25.

Further, (I) or (III) in FIG.
As shown in (1), when the direction of the external force applied to the first optical fiber 21 is different, the bending state of the optical fiber 21 near the optical fiber stopper 26 changes. That is, in the bending state shown in (I) of FIG.
Becomes θ (+), and becomes θ (−) in the bending state shown in (III) of FIG.

Therefore, FIGS. 6 (a)-(I)-(II)
According to each bending state (bending angle θ) shown in I), FIG.
(B) Light losses A1, A2, and A3 as shown in the graphs of (I) to (III) are obtained. That is, since the bending angle θ of the first optical fiber 21 corresponds to the light loss,
By calculating the light loss, the bending direction and the bending angle can be obtained.

The operation of the endoscope shape detecting device 1 configured as described above will be described. First, a signal for emitting pulse light is output from the pulse generation circuit 32 to the laser devices 33a and 33b. Then, this laser device 33
The laser pulse light is emitted from a and 33b toward the laser light incident end faces of the first optical fiber 21 and the second optical fiber 22 provided in the optical fiber cable 15 connected to the connection portion 18.

Each pulse light shown by a solid line and emitted from the laser device 33a, 33b toward the optical fiber 21, 22 is converted into a beam splitter 34a, 34b.
Passes through the first optical fiber 21 and the second optical fiber 22 and propagates toward the distal end.

Next, the backward scattered light returns to the laser light incident end faces of the first optical fiber 21 and the second optical fiber 22. The backward scattered light shown by the broken line returning to the laser light incident end face side is reflected by the beam splitters 34a and 34b, enters the APDs 35a and 35b, and is converted into an electric signal proportional to the incident backward scattered light intensity. Is converted. The electric signals converted by the APDs 35a and 35b are output to the signal processing circuit 31 after being amplified by the amplifiers 36a and 36b.

In the signal processing circuit 31 which has received the electric signals from the amplifying devices 36a and 36b, the bending directions at the respective positions of the bending angle detectors 25 provided in the first optical fiber 21 and the second optical fiber 22, respectively. To calculate the bending angle and the bending angle, the intensity of the backward scattered light is calculated. Then, from the intensity value of the backward scattered light,
The bending direction and the bending angle in the bending angle detecting section 25 over the entire length of the insertion section 7 are obtained, and the insertion section 7 is calculated from these values.
Is generated as a video signal.

Then, the video signal generated by the signal processing circuit 31 is output to the monitor 17, and the curved shape of the insertion section 7 is displayed on the monitor 17 screen.

As described above, the first optical fiber and the second optical fiber are disposed in the insertion section of the endoscope in the longitudinal direction, and the pulse light is propagated through the first optical fiber and the second optical fiber. By measuring the backward scattered light over the entire length of the insertion portion and calculating the amount of light loss at each position of the bending angle detecting section, the bending direction and the bending angle at each bending angle detecting section can be obtained. With this, a video signal is generated based on the bending direction and the bending angle in each of the bending angle detection units, so that the video signal is displayed on a monitor screen to visually check the curved shape of the insertion unit. An endoscope can be inserted.

Further, by measuring the intensity of the backward scattered light generated when the pulse light is propagated through the first optical fiber and the second optical fiber disposed in the insertion section of the endoscope, the endoscope can be measured. Therefore, it is not necessary to reciprocate the first optical fiber and the second optical fiber, so that the curved shape of the endoscope insertion section can be detected without increasing the diameter of the insertion section of the endoscope.

In the configuration of the present embodiment, the connecting portion 18
Pulse light is optically incident on the end faces of the first optical fiber 21 and the second optical fiber 22 provided in the optical fiber cable 15 connected to
The first optical fiber 21 and the second optical fiber 2
Although two semiconductor lasers, two beam splitters, two APDs, and two amplifying devices are provided for converting the backward scattered light from 2 into an electric signal, light switching means such as a rotary mirror is provided in the optical path. Thus, the semiconductor laser, the beam splitter, the APD, and the amplifying device can be configured as one.

In the present embodiment, the first optical fiber and the second optical fiber are disposed in the endoscope insertion section to determine the three-dimensional curved shape of the endoscope insertion section. More than three optical fibers may be provided in the insertion section to obtain a three-dimensional curved shape.

7 to 9 relate to a second embodiment of the present invention. FIG. 7 is an explanatory view showing a schematic configuration of an endoscope and a longitudinal sectional view of an endoscope insertion portion, and FIG. 8 is an endoscope. FIG. 9 is a cross-sectional view showing a configuration of the shape detection probe in a front view and a longitudinal direction, and FIG. 9 is a cross-sectional view showing a state in which the endoscope shape detection probe is inserted into a conduit channel of the endoscope. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.

As shown in FIG. 7, the endoscope 40 of this embodiment is
Is different from the endoscope 2 of the first embodiment in the following two points. That is, the endoscope 40 of the present embodiment has the conduit channel 41 such as a treatment instrument insertion channel.
In the endoscope 40 of the present embodiment, instead of providing the optical fiber cable 15, a communication port 41 a communicating with the conduit channel 41 is provided in the operation unit 8. Then, an endoscope shape detection probe 42, which will be described later, is inserted through the conduit channel 41. The channel 4
Reference numeral 1 communicates with an opening 41b provided on the distal end surface of the insertion section 7.

As shown in FIGS. 8A and 8B, the endoscope shape detection probe 42 is provided with a first optical fiber 21 and a second optical fiber 22. The first optical fiber 21 and the second optical fiber 22 are provided with a plurality of bend angle detectors 25 at arbitrary intervals.

The outer diameter of the endoscope shape detecting probe 42 is determined by the conduit channel 41 provided in the endoscope 40.
The diameter is set smaller than the inner diameter of. Although not shown, one end of the endoscope shape detection probe 42 is connected to the connection portion 18 of the control device 16, and the other end is inserted into the vicinity of the tip of the insertion portion 7 of the conduit channel 41. That is, the endoscope 40 and the endoscope shape detection probe 42
The endoscope shape detection probe 42 is detachable from the conduit channel 41. That is, as shown in FIG. 9, the endoscope shape detection probe 42 is used by being inserted into the channel 41 of the endoscope 40.

As described above, an endoscope shape detecting probe which can be inserted into and removed from a conduit channel provided in an endoscope is constituted, and this endoscope shape detecting probe is connected to a normal endoscope having a conduit channel. In this case, the curved shape of the endoscope insertion portion can be easily detected using the endoscope shape detection probe. This makes it possible to easily confirm the curved shape of the endoscope insertion section without increasing the outer dimensions of the endoscope having the conduit channel. Other functions and effects are the same as those of the first embodiment.

FIG. 10 is an explanatory diagram showing a configuration of an optical fiber according to the third embodiment of the present invention.

As shown in the figure, in this embodiment, the optical fiber 50 is provided with a plurality of angle detectors 51a and 51b for detecting the curved shape of the endoscope at a plurality of locations. The configuration of each of the angle detection units 51a and 51b is the same as the configuration of the angle detection unit 25 shown in FIG. 3C, and the optical fiber 50 is arranged only in one direction inside the bending angle detection units 51a and 51b. It is turning.

As shown in FIG. 10, a pair of bend angle detectors 51a and 51b are arranged at predetermined intervals along the longitudinal direction of the optical fiber 50. Parts 51a and 51b are provided alternately. This is because the bending angle detector 5
This is because 1a is set so as to bend only in the vertical direction in the drawing, and the bending angle detecting section 51b is set so as to bend only in a direction perpendicular to the paper surface in the drawing. That is, the angle detection unit 51a and the angle detection unit 51b are arranged at substantially the same position in a positional relationship orthogonal to each other at 90 degrees, so that detection in the left-right direction and the up-down direction can be performed. Other configurations are the same as those of the above-described embodiment.

As described above, the bending angle detecting section set to bend only in the vertical direction and the bending angle detecting section set to bend only in the direction perpendicular to the plane of the drawing in FIG. By providing a pair at substantially the same position and providing them at a plurality of locations, this one optical fiber can be provided in the endoscope of the first embodiment,
By providing the endoscope shape detection probe of the second embodiment, the curved shape of the endoscope insertion section can be detected three-dimensionally. Thus, the configuration using two optical fibers in the first embodiment and the second embodiment is reduced to one.
It becomes possible to configure with the optical fiber of the book. Thus, it is possible to detect the shape of the endoscope insertion section without making the insertion section 7 of the endoscope 2 or the endoscope 40 thick.

Further, by using one optical fiber for detecting the endoscope shape, one set of laser device, beam splitter, APD and amplifying device in the endoscope shape detection control device can be used. One by one. Thus, an inexpensive endoscope shape detection control device is configured.

In the present embodiment, the bend angle detectors 51a and 51b are formed separately, but the bend angle detectors 51a and 51b may be integrated. Other operations and effects are the same as those of the above-described embodiment.

The present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist of the invention.

[Appendix] According to the embodiment of the present invention described in detail above, the following configuration can be obtained.

(1) An optical fiber provided with a plurality of bend angle detecting portions, an endoscope in which the optical fibers are arranged along the longitudinal direction in an endoscope insertion portion, and pulse light irradiation for supplying pulse light to the optical fibers Means, light detecting means for detecting backward scattered light generated at an arbitrary position of the optical fiber by the pulse light from the pulse light irradiating means incident on the optical fiber, and backward scattered light detected by the light detecting means An endoscope shape detection device comprising: a signal processing means for calculating a bending direction and a bending angle in a bending angle detection unit provided in the optical fiber from the intensity of light and generating an endoscope insertion unit shape into a video signal. .

(2) An endoscope shape detection probe having a built-in optical fiber having a plurality of bend angle detection portions, and a tube provided with the endoscope shape detection probe which can be inserted and removed and which is provided in the longitudinal direction in the endoscope insertion portion. An endoscope having a road channel;
Pulse light irradiation means for supplying pulse light to the optical fiber, and light detection means for detecting backward scattered light generated at an arbitrary position of the optical fiber by the pulse light from the pulse light irradiation means incident on the optical fiber. ,
A signal processing means for calculating a bending direction and a bending angle in a bending angle detection unit provided in the optical fiber from the intensity of the backward scattered light detected by the light detection unit, and generating an endoscope insertion unit shape into a video signal; An endoscope shape detecting device comprising:

(3) The endoscope shape detecting device according to Supplementary Note 1 or 2, wherein the optical fiber is bent at the bending angle detecting unit.

(4) The endoscope shape detecting apparatus according to appendix 1 or appendix 2, wherein the bending angle detecting section is provided with three optical fiber stoppers.

(5) The endoscope shape detecting device according to Supplementary Note 1 or 2, wherein the optical fiber is a single mode fiber.

(6) The endoscope shape detecting device according to Supplementary Note 1 or 2, wherein the pulsed light irradiating means is a laser device.

(7) The endoscope shape detecting device according to appendix 6, wherein the laser device is a semiconductor laser.

(8) The endoscope shape detecting device according to Supplementary Note 1 or 2, wherein the light detecting means is an avalanche photodiode.

(9) The endoscope shape detecting device according to Supplementary Note 1 or 2, wherein the backward scattered light is Rayleigh scattered light.

(10) The endoscope shape detecting apparatus according to Supplementary Note 1 or 2, wherein the number of the optical fibers is plural.

(11) The endoscope shape detecting apparatus according to appendix 10, wherein the optical fibers are a first optical fiber and a second optical fiber.

(12) The endoscope shape detecting apparatus according to appendix 11, wherein the first optical fiber and the second optical fiber are arranged so as to be shifted from each other by 90 degrees.

(13) The endoscope shape detecting device according to appendix 1 or 2, wherein the number of the optical fibers is one.

(14) The endoscope shape detecting device according to appendix 13, wherein the bend angle detecting units are alternately arranged by being shifted by 90 degrees in a direction in which the optical fiber bends.

[0079]

As described above, according to the present invention, it is possible to easily detect the shape of the endoscope insertion portion without increasing the outer diameter of the endoscope insertion portion. An endoscope shape detection device can be provided.

It is possible to detect the curved shape of the endoscope insertion section without making the endoscope insertion section thick.

[Brief description of the drawings]

FIG. 1 to FIG. 6 relate to a first embodiment of the present invention, and FIG. 1 is an explanatory diagram showing a schematic configuration of an endoscope shape detecting device.

FIG. 2 is a sectional view of an insertion portion of the endoscope.

FIG. 3 is an explanatory diagram showing a schematic configuration of an optical fiber disposed in an insertion section.

FIG. 4 is a block diagram showing a configuration of a shape detection control device.

FIG. 5 is a flowchart illustrating the operation of the shape detection control device.

FIG. 6 is a diagram showing a relationship between a bent state and light loss in the angle detection unit.

7 to 9 relate to a second embodiment of the present invention, and FIG. 7 is an explanatory view showing a schematic configuration of an endoscope and a longitudinal sectional view of an endoscope insertion portion.

FIG. 8 is a front and longitudinal sectional view showing a configuration of an endoscope shape detection probe.

FIG. 9 is a cross-sectional view showing a state in which an endoscope shape detection probe is inserted into a conduit channel of the endoscope.

FIG. 10 is an explanatory diagram showing a configuration of an optical fiber according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 3 ... Shape detection control device 16 ... Control device 21, 22 ... Optical fiber 31 ... Signal processing circuit 32 ... Pulse generation circuit 33a, 33b ... Laser device 35a, 35b ... Avalanche photodiode (AP)
D) 36a, 36b ... Amplifier

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[Procedure amendment]

[Submission date] December 24, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction contents]

The control device 16 includes a signal processing circuit 31 as a signal processing means for generating a video signal, a pulse generating circuit 32 as a pulse generating means, laser devices 33a and 33b as pulse light irradiating means, beam splitter 34a is directional coupling means, and 34b, (hereinafter abbreviated as APD) avalanche E photodiode which is a light detecting means 35a, and 35b, this APD35a, 35b
It mainly comprises amplification devices 36a and 36b, such as operational amplifiers, which are amplification means for amplifying the signal detected in step (1), and a connection portion 18 to which the base end of the optical fiber cable 15 is detachably connected.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0072

[Correction method] Change

[Correction contents]

[0072] (8) the light detecting means, the endoscope shape detecting apparatus of Supplementary Note 1 or 2, wherein the avalanche E off <br/> photodiode.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] Explanation of sign

[Correction method] Change

[Correction contents]

[Reference Numerals] 3 ... shape detection control unit 16 ... controller 21 ... optical fiber 31 ... signal processing circuit 32 ... pulse generating circuit 33a, 33b ... laser device 35a, 35b ... avalanche E photodiode (AP
D) 36a, 36b ... Amplifier

[Procedure amendment 4]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

[Procedure amendment 5]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

Claims (1)

[Claims] 1. An optical fiber provided with a plurality of bend angle detectors, an endoscope having the optical fibers arranged along a longitudinal direction in an endoscope insertion portion, and a pulse light irradiator for supplying pulse light to the optical fibers. Light detecting means for detecting backward scattered light generated at an arbitrary position of the optical fiber by pulsed light from the pulsed light irradiating means incident on the optical fiber; and backward scattered light detected by the light detecting means. Signal processing means for calculating a bending direction and a bending angle in a bending angle detecting unit provided in the optical fiber from the intensity of the optical fiber, and generating an endoscope insertion unit shape into a video signal. Mirror shape detection device.