JP2003065733A - Flexible endoscopic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible endoscopic device which can detect and display the bent state of a flexible tube at an inserting section without containing a large error even in the case breakage or the like takes place at a portion of a plurality of optical fibers for detecting bend. SOLUTION: The flexible endoscopic device has a bent state detecting means 40 which sets a threshold value for detected values of the light transmitted by each optical fiber for detecting bend 21. The bent state around a bend detecting section 222 disposed on the optical fiber for detecting bend 21, the amount of light transmitted by which deviates from the threshold value, is set approximately from the bent states of bend detecting sections 221 , 223 disposed before and after it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible endoscope device for observing the inside of the gastrointestinal tract.

[0002]

2. Description of the Related Art A flexible endoscope device to be inserted into the gastrointestinal tract or the like has a flexible insertion part flexible tube that bends freely along the inner wall of the gastrointestinal tract or the like. It is difficult to grasp the bending state of the body from outside the body.

Therefore, it is impossible to determine what state the flexible tube is inserted into the gastrointestinal tract,
It may not be possible to determine how to perform the next insertion / removal operation.

Therefore, if the X-ray fluoroscopy is performed, it is possible to see the bent state of the flexible tube of the insertion portion. However, the X-ray irradiation need not only be performed in a special room surrounded by a thick lead wall or the like. However, continuous fluoroscopy has a problem of radiation exposure, which may have a very bad influence on the human body.

Therefore, a magnetic field generating member is attached to the tip of the insertion portion of the endoscope, and the position of the magnetic field generating member is detected by a magnetic sensor arranged outside the human body to determine the position of the tip of the insertion portion inside the body. There is one that is designed to be displayed on a monitor screen (Japanese Patent No. 2959723).

[0006]

However, in the apparatus for detecting the position of the magnetic field generating member attached to the distal end of the insertion portion as described above, the bending of the flexible tube of the insertion portion can be performed only by knowing the position of the distal end of the insertion portion. The state is unknown, and moreover, such a device is easily affected by external noise, and there are many cases where position detection cannot be continued in a good state.

Therefore, the inventors of the present invention have provided a plurality of flexible bend detecting optical fibers having a bend detecting portion in which the amount of transmitted light changes in accordance with the size of the bent angle. The flexibility to detect the bending state of the flexible tube of the insertion section at the position where each bending detection section is located from the light transmission amount of each bending detection optical fiber and to display the bending state on the monitor screen. He has invented an endoscope apparatus and has previously filed a patent application (Japanese Patent Application No. 2001-2001).
53715).

The present invention is an improvement of the invention. Even if a part of the plurality of bend detecting optical fibers is broken, the bending state of the flexible tube of the insertion portion can be detected and displayed without a large error. An object of the present invention is to provide a flexible endoscope device that can be used.

[0009]

In order to achieve the above object, the flexible endoscope apparatus of the present invention has a bend detecting section in which the amount of transmitted light changes in accordance with the size of the bent angle. A plurality of flexible bend detecting optical fibers formed with a plurality of bend detecting parts are arranged side by side in the axial direction of the flexible tube of the insertion part, and each bend is detected from the optical transmission amount of each bend detecting optical fiber. Bending state detection means for detecting the bending state of the insertion portion flexible tube at the portion where the detection portion is located is provided, and the bending state of the insertion portion flexible tube is displayed on the monitor screen based on the output signal from the bending state detection means. In the flexible endoscope apparatus configured as described above, in the bending state detecting means, a threshold value is set for the detection value of the light transmission amount of each bend detecting optical fiber, and the light transmission amount deviating from the threshold value is set. Is inspected Has been bent flexion bend near detector provided the detection optical fiber is obtained so as to set approximately from the bent state of the detection portion bend located before and after.

In the bending state detecting means, the bending state before and after the bending detection section is detected as the bending state of the bending detection section formed on the bending detection optical fiber in which the amount of light transmission deviating from the threshold value is detected. You may make it give the substantially average value of the bending state in a part.

Further, the bend detecting section may be such that the light absorbing section is formed only in a predetermined direction in the middle of the bend detecting optical fiber. The bend detecting optical fiber may be arranged along the outer skin of the insertion portion flexible tube, or the bending detection optical fiber may be arranged to be inserted through the insertion portion flexible tube.

Further, the position of the bend detecting optical fiber in which the amount of light transmission deviating from the threshold value is detected by the bending state detecting means may be displayed on the monitor screen so that it can be identified.

[0013]

Embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows the overall configuration of the flexible endoscope apparatus. The proximal end of the insertion portion flexible tube 1 is connected to the lower end of the operation portion 2, and the portion near the tip of the insertion portion flexible tube 1 is The curved portion 1a is bent in an arbitrary direction by rotating the operation knob 3 arranged on the operation portion 2.

A distal end body 4 having an observation window and the like is connected to the distal end of the flexible tube 1 of the insertion portion.
A video signal of an endoscopic observation image picked up by a solid-state imaging device (not shown) built in the camera is sent to an external video processor 7 through a video signal line 6 extending from the operation unit 2, and the endoscope is The observation image is displayed on the observation image monitor 8.

The flexible tube 1 of the insertion section is made of a flexible synthetic resin in which a plurality of optical fibers for bending detection, which will be described later, are arranged in a position in the extension direction of the front surface of the operation section 2 (that is, in the upward direction on the observation screen). The belt-shaped member 20 is attached, and its base end is connected to the optical signal input / output device 30.

The signal output line of the optical signal input / output device 30 is connected to the computer 40, and the computer 40
An insertion state display monitor 41 that displays an image using a cathode ray tube or a liquid crystal is connected to the. 42 is
A speaker connected to the computer 40.

FIG. 3 shows the vicinity of the tip of the flexible tube 1 of the insertion portion, and the observation window 11 and the illumination window 1 are provided on the tip surface of the tip end main body 4.
2. The treatment tool projecting opening 13 and the like are arranged, and the subject illuminated by the illumination light emitted from the illumination window 12 is the observation window 11
An image is formed on the image pickup surface of the solid-state image pickup device by an objective optical system (not shown) arranged inside.

The band-shaped member 20 is arranged in close contact with the outer surface of the flexible tube 1 in the "upward direction" in parallel with the axis of the flexible tube 1 and, for example, from the outer side of the flexible tube 1. The flexible tube 1 is wrapped with a heat-shrinkable tube, and is pressed and fixed.

However, the band-shaped member 20 may be fixed to the flexible tube 1 of the insertion portion by any means such as bonding. Further, the belt-shaped member 20 may be inserted and arranged in the insertion portion flexible tube 1, or the bending detection optical fiber 21 may be attached to a built-in object that is inserted and arranged in the insertion portion flexible tube 1 to attach the belt-shaped member 20. You can omit it.

As shown in FIG. 3, the plurality of bend detecting optical fibers 21 are sequentially bent back to a smooth U-shape by changing their positions. The bend detecting section 22 is provided near the bend-back section of each bend detecting optical fiber 21.
Are formed.

The bend detecting section 22 has a space of, for example, about several centimeters in the axial direction of the insertion section flexible tube 1,
For example, about 5 to 30 pieces are arranged over the entire length of the insertion portion flexible tube 1.

The bend detecting section 22 is a bend detecting optical fiber 2 in which a plastic core is covered with a clad.
1, a light absorbing portion is formed only in a predetermined direction (for example, an upward direction or a downward direction), and the amount of transmitted light changes in accordance with the degree to which the bend detecting portion 22 is bent. Therefore, by detecting it, it is possible to detect the bending angle of the portion where the bending detection unit 22 is arranged.

Regarding the principle, US Pat. No. 56334
As described in No. 94, etc., a brief description will be given below. In FIG. 4, reference numerals 21a and 21b denote a core and a clad of one bend detecting optical fiber 21, and the bend detecting section 22 absorbs the light passing through the core 21a without totally reflecting it inside the core 21a. The light absorbing portion 22a is formed in a specific direction (here, “downward”) of the clad 21b.

Then, as shown in FIG. 5, when the bend detecting optical fiber 21 is bent upward, the core 2
Since the amount (area) of the light that reaches the light absorbing portion 22a of the light passing through the inside of 1a is increased, the bend detecting optical fiber 21
The light transmission amount of is reduced.

On the contrary, as shown in FIG. 6, when the bend detecting optical fiber 21 is bent downward, the core 21
Since the amount (area) of the light that passes through the inside of a and hits the light absorbing portion 22a decreases, the amount of light transmission of the bend detection optical fiber 21 increases.

Since the bending amount and the light transmission amount of the bending detection optical fiber 21 in the light absorbing portion 22a have a constant relationship (for example, a linear function relation), the light transmission amount of the bending detection optical fiber 21 is By detecting, the bend detecting section 22 in which the light absorbing section 22a is formed
The bending angle of the part can be detected.

Therefore, when a plurality of bend detecting portions 22 are arranged at intervals in the axial direction of the insertion portion flexible tube 1, the intervals between the bend detecting portions 22 and the detected bend detecting portions are detected. The bending state of the entire insertion portion flexible tube 1 in the vertical direction can be detected from the bending angle of 22.

Then, as schematically shown in FIG. 7, a second bend detecting section 22 'is further arranged in parallel with the bend detecting section 22 as described above, and two bend detecting sections 22 arranged side by side, Comparing the light transmission amounts of 22 ', when there is no twist in the left-right direction, there is no difference in the light transmission amounts of the two, and the difference in the light transmission amounts of the two becomes large according to the twist amount in the left-right direction.

Therefore, each bend detecting section 22, 22 '
It is possible to detect the amount of twist in the left-right direction of the portion where the bend detecting portions 22 and 22 'are arranged by measuring the amount of light transmission of the above and comparing the measured values. This principle is as described in US Pat. No. 6,127,672.

Therefore, the plurality of bend detecting portions 22 are arranged at a predetermined interval in the axial direction of the insertion portion flexible tube 1, and the second plurality of bend detecting portions 22 'are arranged in parallel with each other, and each bend is arranged. The three-dimensional bending state of the entire insertion portion flexible tube 1 can be detected by detecting and comparing the amount of light transmission in the detection portions 22 and 22 '.

Therefore, in the flexible endoscope apparatus of the present embodiment, as shown in FIG. 8, a plurality of bends are arranged so that the bend detecting portions 22 are located at regular intervals in the longitudinal direction of the belt-shaped member 20. The detection optical fiber 21 is attached to the front surface side of the strip-shaped member 20, and the second plurality of bend detection portions 22 ′ are arranged next to each of the front-side bend detection portions 22 so that a second plurality of strip-shaped members 20 are provided. A bend detecting optical fiber 21 'is attached.

Further, at least one simple reference optical fiber 21R in which the light absorbing portion 22a is not formed is arranged, and the optical transmission amount of each bend detecting optical fiber 21 is compared with the optical transmission amount of the reference optical fiber 21R. Therefore, bend detection optical fiber 2
It is possible to eliminate the influence of temperature, deterioration over time, etc. on the light transmission amount of 1.

FIG. 9 shows an optical signal input / output device 30, in which light emitted from one light emitting diode 31 is incident on all the optical fibers 21, 21 'and 21R. 32
Is a drive circuit of the light emitting diode 31.

Then, each optical fiber 21, 21 ', 2
A photodiode 33 that converts the intensity level of light into a voltage level and outputs the voltage level is provided for each of the 1R emission ends.
The output from each photodiode 33 is amplified by the amplifier 34, converted into a digital signal by the analog / digital converter 35, and sent to the computer 40.

When the insertion portion flexible tube 1 of the flexible endoscope apparatus thus constructed is inserted into the body, the insertion portion guide member 50 is inserted into the body as shown in FIG. Attached to the inlet portion (eg mouth or anus), the insert flexible tube 1 is threaded within its insert guide member 50.

Therefore, the insertion portion guide member 50 is provided with an encoder 60 or the like for detecting the insertion length L of the insertion portion flexible tube 1 (that is, the length of passage through the insertion portion guide member 50). Output signal of computer 4
It is supposed to be sent to 0.

FIG. 11 shows such an insertion portion guide member 50.
An example is shown, in which a plurality of rotatable spherical members 51 urged by the compression coil springs 52 are arranged so as to sandwich the insertion portion flexible tube 1 from the surroundings.

Therefore, each spherical member 51 rotates in proportion to the insertion length L of the insertion portion flexible tube 1, and one of the spherical members 51 is proportional to the insertion length L of the insertion portion flexible tube 1. An encoder 60 that outputs a number of pulses is connected.

However, the insertion length L of the insertion portion flexible tube 1 in the insertion portion guide member 50 is detected by, for example, Japanese Patent Laid-Open No. 56-9.
As described in JP-A-7429 and JP-A-60-217326, light reflection from the surface of the flexible tube 1 of the insertion portion may be used, and other means may be used.

In this way, as shown in FIG. 10, the bending state detection signal and the insertion length detection signal of the insertion portion flexible tube 1 are input to the computer 40 from the optical signal input / output device 30 and the encoder 60, Image 5 of insertion part guide member 50
0'and an image 1'indicating the bent state of the insertion portion flexible tube 1 are displayed on the insertion state display monitor 41.

At this time, the image 5 of the insertion portion guide member 50
The display position of 0 ′ is fixed on the insertion state display monitor 41, and an image 1 ′ showing the bending state of the insertion portion flexible tube 1 at the portion inserted in front of it is displayed as a change of the insertion portion flexible tube 1. The state of the insertion portion flexible tube 1 in the body can be easily grasped by changing it in real time according to the above.

However, if a plurality of bend detecting optical fibers 21 are broken and the light input from the bend detecting optical fibers 21 to the photodiode 33 is stopped, the bend detecting optical fibers 21 are not provided.
The bending state in the bending detection unit 22 provided in the is incorrectly detected.

[0043] Figure 12 illustrates the state in the bending are arranged in the middle of the belt-shaped member 20 arranged in the flexible tube 1 detector 22 (22 _1, 22 _2, 22 ₃₎ When the light output from the bend detection section 22 _{2 in} the middle of
As shown by the broken line, at the position of the bend detecting portion 22 ₂ , the insertion portion flexible tube 1 is detected as if it is abruptly bent.

Therefore, in the present invention, "the threshold value of the detected value of the light transmission amount of the bend detecting optical fiber 21" is set in the software for detecting the bending state of the insertion portion flexible tube 1, and the The bending state in the vicinity of the bending detection section 22 ₂ provided in the bending detection optical fiber 21 in which the amount of light transmission deviating from the threshold value is detected depends on the bending states of the bending detection sections 22 ₁ and 22 ₃ located before and after the bending detection section 22 ₂ . It is set approximately.

In this embodiment, the bending detecting portion 2 located before and after the bending angle θ ₂ of the bending detecting portion 22 ₂ which gives an optical output deviating from such a threshold value.
The average value of the bending angles of 2 ₁ and 22 ₃ (that is, θ ₂ = (θ ₁
+ Θ ₃ ) / 2).

As a result, as shown by the solid line in FIG. 12, the bend detecting section 2 relating to the optical output deviating from the threshold value.
As long as the bending state of the insertion portion flexible tube 1 does not change abruptly between the bend detection portions 22 ₁ and 22 ₃ located before and after 2, the insertion portion flexible tube 1 is The same state as when the bending state of 1 is detected with almost no error is obtained.

However, in the approximate setting of the bending state of the bend detecting section 22 ₂ which gives an optical output deviating from the threshold value, even if the processing is performed assuming that the bend detecting section 22 ₂ does not exist, it is almost the same as above. The same result is obtained.

Alternatively, before and after the bend detecting section 22 ₂ relating to the light output deviating from the threshold value, the bending states of a plurality of bending detecting sections 22 _1, ..., 22 ₃ ... Are respectively detected and based on those states. Therefore, the bent state of the detection unit 22 ₂ that can obtain the optical output deviating from the threshold value may be set.

FIG. 1 is a flow chart showing an outline of the contents of software of the computer 40 for displaying the image 1'of the bent state of the flexible tube 1 of the insertion portion on the insertion state display monitor 41 as described above. , S in the figure indicates a step.

In order to display the accurate bending state on the insertion state display monitor 41, first, before inserting the insertion portion flexible tube 1 into the body, the insertion portion flexible tube 1 of the endoscope actually used is inserted. It is preferable to perform a calibration to compare the bending angle of B with the detection signal obtained from the bend detecting optical fiber 21 (S1).

When the insertion portion flexible tube 1 is inserted into the body, a detection signal of the insertion length L of the insertion portion 1 is input from the encoder 60 (S2), and the insertion portion guide member 50 is inserted into the insertion portion flexible tube 1. It is calculated which position is in (S3).

Next, each bend detecting optical fiber 21
The detection signal V _n (n = 1,2,3, ...) Is input (S4), and the detection signal V _n (n = 1, 2, 3, ...) is compared with a preset threshold value. Yes (S5).

Then, the detection signal V _n (n = 1, 2, 3,
Is larger than the threshold value, the detection signal V _n is converted into a bending angle based on the calibration data (S6), and the position of each bending detection unit 22 on the three-dimensional coordinates is calculated (S9).

At S5, the detection signal V _n (n = 1, 2,
, 3) is not larger than the threshold value, for example, the bend detection unit 22 ₂ that obtains an optical output deviating from the threshold value.
The bending angle θ ₂ of the
Approximately set to the average value of the bending angles of 2 ₁ and 22 ₃ (S
7).

Then, a warning indicating that the light output deviating from the threshold value is detected is output from, for example, the speaker 42 as a warning, and the process proceeds to S9. However, the warning may be displayed on the insertion state display monitor 41 or the like.

In this case, the position of the bending detecting optical fiber 21 where the amount of light transmission outside the threshold value is detected can be identified on the monitor screen on which the bending state of the flexible tube 1 for insertion is displayed. You may make it change and display it.

When the position of each bend detecting section 22 on the three-dimensional coordinates is calculated in this way, the image 50 'of the insertion section guide member 50 is displayed on the insertion state display monitor 41.
The position of each bending detection unit 22 is smoothly connected and displayed while the position of No. is not moved to display the bending state of the insertion portion flexible tube 1 (S10), and until the end instruction is input, S2 to S10 is repeated (S11).

When performing such a display, the display on the insertion state display monitor 41 is a two-dimensional image, but since three-dimensional data about the position of each bend detecting portion 22 is obtained, "upper" is displayed. It is possible to display not only the "direction" but also the bending state of the insertion portion flexible tube 1 in an arbitrary rotation direction.

Further, the spherical member 51 of the insertion portion guide member 50.
From this, the rotation direction around the axis of the insertion portion flexible tube 1 is detected,
If the display image of the insertion state display monitor 41 is rotated according to the amount of rotation of the insertion portion flexible tube 1 about the axis, the insertion state display monitor 41 displays an image as if the orientation of the patient's body is fixed. Can be made.

[0060]

According to the present invention, when a light transmission amount deviating from a threshold value is detected as the light transmission amount of each bend detecting optical fiber, the bend detecting section provided in the bend detecting optical fiber is detected. The bending condition near the curve is set approximately based on the bending conditions of the bending detection parts located in front of and behind it, so even if a part of the bending detection optical fiber is broken, the flexible tube The bent state can be detected and displayed without a large error.

[Brief description of drawings]

FIG. 1 is a flow chart outlining the contents of software of a computer according to an embodiment of the present invention.

FIG. 2 is a schematic view of the overall configuration (excluding the insertion portion guide member) of the flexible endoscope apparatus according to the embodiment of the present invention.

FIG. 3 is a perspective view of the vicinity of the distal end of the flexible tube of the insertion section of the flexible endoscope apparatus according to the embodiment of the present invention.

FIG. 4 is a schematic sectional view of a bend detecting portion of the bend detecting optical fiber used in the embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view showing a state in which the bend detecting portion of the bend detecting optical fiber used in the embodiment of the present invention is bent.

FIG. 6 is a schematic cross-sectional view showing a state in which the bend detecting portion of the bend detecting optical fiber used in the embodiment of the present invention is bent in the opposite direction.

FIG. 7 is a schematic diagram for explaining the principle of three-dimensional bending state detection by the bending detection optical fiber used in the embodiment of the present invention.

FIG. 8 is a plan view of a belt-shaped member to which a bend detecting optical fiber according to an embodiment of the present invention is attached.

FIG. 9 is a circuit diagram of an optical signal input / output device according to an embodiment of the present invention.

FIG. 10 is a schematic diagram showing an overall configuration of a flexible endoscope apparatus according to an embodiment of the present invention in use.

FIG. 11 is a front sectional view of an insertion portion guide member according to the embodiment of the present invention.

FIG. 12 is a schematic view illustrating setting of a bending state when the bending detecting optical fiber of the embodiment of the present invention is broken or the like.

[Explanation of symbols]

1 Flexible tube Image of 1'insertion flexible tube bent 20 band-shaped members 21,21 'Optical fiber for bend detection 22,22 'bend detection section 30 Optical signal input / output device 40 computer (bending state detecting means) 41 Insert status monitor 50 Insertion part guide member Image of 50 'insertion part guide member

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI theme code (reference) H04N 7/18 H04N 7/18 M (72) Inventor Kazuki Yamamoto 3-25 Nishishinbashi, Minato-ku, Tokyo No. 8 School Hojin Jikei University (72) Inventor Minoru Matsushita Maenocho 2-36-3, Itabashi-ku, Tokyo No. 9 Asahi Kogaku Kogyo Co., Ltd. (72) Inventor Akira Sugiyama 2-36 Maenocho, Itabashi-ku, Tokyo No. 9 Asahi Kogaku Industry Co., Ltd. (72) Inventor Satoshi Takami 2-36 Maeno-cho, Itabashi-ku, Tokyo No. 9 Asahi Kogaku Industry Co., Ltd. (72) Inventor Takayuki Enomoto 2-3-36 Maeno-cho, Itabashi-ku, Tokyo No. 9 Asahi Kogaku Industry Co., Ltd. F-term (reference) 2F065 AA31 AA65 BB12 BB22 CC23 GG07 GG12 QQ03 SS02 2H040 BA21 BA23 DA15 4C061 AA01 BB02 CC06 DD03 FF24 FF46 HH51 JJ17 NN05 WW11 5C022 A4 A01 AC51 5A05 AC51 5A05 C02 HA12

Claims (6)

[Claims] 1. A flexible optical fiber for bending detection, wherein a plurality of bending detection portions are formed, in which the amount of transmitted light changes in accordance with the size of the bent angle. A bending state which is arranged side by side in the axial direction of the pipe with a space therebetween and detects the bending state of the insertion section flexible tube at the portion where each bending detection section is located from the light transmission amount of each bending detection optical fiber. In the flexible endoscope device configured to be provided with a detection unit, the bending state of the insertion portion flexible tube is displayed on a monitor screen based on an output signal from the bending state detection unit,
In the bending state detecting means, a threshold value is set for the detection value of the light transmission amount of each of the bend detection optical fibers, and the bend detection optical fiber is detected when the light transmission amount deviating from the threshold value is detected. The flexible endoscope apparatus is characterized in that the bending state near the bend detecting section is set approximately based on the bending states of the bending detecting sections located before and after the bending detecting section. 2. A bending state of the bending detecting portion formed on the bending detecting optical fiber in which the amount of light transmission deviating from the threshold value is detected by the bending state detecting means, and the bending detecting portion is provided before and after the bending detecting portion. The flexible endoscope apparatus according to claim 1, wherein a substantially average value of the bending state in the bend detecting portion is given. 3. The flexible endoscope apparatus according to claim 1, wherein the bend detecting section has a light absorbing section formed in a predetermined direction in the middle of the bend detecting optical fiber. 4. The flexible endoscope apparatus according to claim 1, wherein the bend detecting optical fiber is arranged along an outer skin of the insertion portion flexible tube. 5. The flexible endoscope apparatus according to claim 1, wherein the bend detecting optical fiber is inserted through the flexible tube of the insertion section. 6. The position of the bend detecting optical fiber in which the amount of light transmission deviating from the threshold value is detected by the bending state detecting means is displayed on the monitor screen in a distinguishable manner. 2. The flexible endoscope apparatus according to item 2.