JP2003220022A - Endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endoscope excellent in an observation capacity and a treatment capacity by sufficiently ensuring the total axial length of a curved part not only to enhance the insertion capacity of an endoscope insertion part but also to realize a sharp turn. <P>SOLUTION: The first curved part 13 on the leading end side of the insertion part 2 and the second curved part 14 behind the first curved part 13 are driven at the same time at the time of an operation of a first up and down curving operation knob 18 and a first left and right curving operation knob 19 and only the second curved part 14 is driven at the time of an operation of a second up and down curving operation knob 20. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope used by being inserted into a lumen having a complicated anatomical shape such as the large intestine.

[0002]

2. Description of the Related Art In general, insertion of an endoscope in colonoscopy requires a procedure because the anatomical complexity of the large intestine and the running and length of the intestine vary widely among individuals. It is said that it is difficult to learn in a short time.

In such an environment, the operator's insertion technique has made progress, and at present, for example, a technique such as light turn shortening for inserting it while hooking a fold of the intestine has been developed. In addition, as another technique, a push method or the like has been developed which facilitates insertion of the endoscope insertion portion into the deep part of the large intestine. This is basically an endoscope that is inserted along the lumen of the large intestine, and if the insertion portion of the endoscope forms a loop or a bend, the bending mechanism makes the endoscope tip end into an arc shape. The loop and the flexure are released while being hooked on the bent part of the intestine, and the endoscope insertion part is inserted.

In addition, in the endoscope inserted into the large intestine, in order to correspond to the above-mentioned procedure, the length in the axial direction of the bending portion for directing the distal end portion of the endoscope insertion portion in a desired direction is set. , Some length is needed.

On the other hand, the large intestine has many folds due to its anatomical characteristics, and in order to observe and treat the back side of the fold, the curved portion of the endoscope is required to have a small turning effect. To be done.

[0006] As a bending mechanism with such a small turning effect,
The applicant of the present application filed a Japanese Patent Application No.
No. 1-2232166 has been filed. In this, a plurality of joint pieces are rotatably connected to the distal end side of the elongated insertion portion, two bending portions that operate independently are connected in series, and a first bending portion disposed on the distal end side of the insertion portion. The axial length dimension of the second bending portion arranged at the rear of is smaller than the axial length dimension of the first bending portion.

[0007]

[Problems to be Solved by the Invention] Japanese Patent Application No. 2001-232
If a curving mechanism with a small turning effect is adopted as in No. 166, observation and treatment of the back side of the folds are facilitated. However, in the insertion procedure for inserting the endoscope insertion portion into the deep part of the large intestine, the bending portion length of the endoscope adopting the bending mechanism with a small turning effect as in Japanese Patent Application No. 2001-232166,
In some cases, the length of the bending portion is insufficient when the operation of hooking the bending portion on the bending portion in order to scrape away the folds or release the loop or bending of the endoscope insertion portion.

Further, as a means for improving the insertability of the endoscope, it is conceivable to lengthen the axial length of the first bending portion, but in this case, the bending shape of the first bending portion becomes large. , A small turn does not work.

Therefore, in the endoscope having the above-mentioned conventional structure, it is very difficult to balance the improvement of the insertion performance of the endoscope insertion section by improving the bending mechanism and the improvement of the observation / treatment performance in a well-balanced manner. It was

The present invention has been made in view of the above circumstances, and an object thereof is to sufficiently secure the total axial length of the bending portion to enhance the insertion performance of the endoscope insertion portion, and It is to provide an endoscope excellent in both observation and treatment performance by realizing an effective curved shape.

[0011]

According to a first aspect of the present invention, there are provided two bending portions formed by rotatably connecting a plurality of joint pieces on the distal end side of an elongated insertion portion, in the axial direction of the insertion portion. A first bending operation unit that is arranged along the first bending section and is arranged at the distal end side of the insertion section, and that simultaneously drives a second bending section arranged behind the first bending section; At least the second bending operation means for driving only one of the first bending portion and the second bending portion is provided in the operation portion connected to the proximal end side of the insertion portion. It's a mirror.

Further, according to the invention of claim 1, when the first bending operation means of the operation portion is operated, the first bending portion on the distal end side of the insertion portion and the second bending portion behind the first bending portion are provided. By operating at the same time, the total axial length of the bending portion is sufficiently secured. Further, at the time of operating the second bending operation means, at least one of the first bending portion and the second bending portion is operated to realize a curved shape with a small turning effect.

According to a second aspect of the present invention, the second bending operation means comprises:
The endoscope according to claim 1, further comprising switching operation means for selectively switching between the first bending portion and the second bending portion.

According to the invention of claim 2, the first bending portion and the second bending portion, which are operated when the second bending operation means is operated, are selectively switched by operating the switching operation means. Is.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a schematic configuration of the entire colonoscope 1 of the present embodiment.
In the main body of the endoscope 1, a proximal operation portion 3 is connected to a proximal end portion of an elongated insertion portion 2 inserted into a lumen.
One end of a universal cord section 4 is connected to the operation section 3. A connector (not shown) is connected to the other end of the universal cord portion 4. The connector is detachably connected to a light source and an image processing device (not shown).

Further, a proximal end portion of the bending portion 6 is connected to the distal end side of the elongated flexible tube portion 7 in the insertion portion 2. The tip end side of the curved portion 6 is connected to the base end portion of the tip end portion 5. As a result, the insertion portion 2 that is flexible and long as a whole is configured.

Further, at the tip portion 5, an observation cover lens 8 forming one end of the observation optical system, a nozzle 9 for cleaning the surface of the observation cover lens 8, and two illumination cover lenses 10. A channel 11 for inserting a treatment tool or the like is provided. Where channel 11
Is communicated with the treatment instrument insertion opening 12 provided in the operation portion 3 via the inside of the insertion portion 2. Then, when the operator performs treatment, the treatment tool is inserted into the channel 11 through the treatment tool insertion opening 12.

Further, the bending portion 6 is composed of a first bending portion 13 which will be described later and which is arranged on the distal end side, and a second bending portion 14 which will be described later which is arranged behind the first bending portion.

The operation section 3 includes a grip section 15 for an operator to hold the endoscope, a main operation section 16 arranged at a rear end of the grip section 15, and a further main operation section 16.
It is composed of an auxiliary operation unit 17 connected to the rear end of the rear end. The main operation part 16 includes a first up / down bending operation knob (first bending operation means) 18 for up / down bending operation, and a first left / right bending operation knob (first bending operation means) 19 for left / right bending operation. And are vertically movably supported independently of each other. Further, a second up / down bending operation knob (second bending operation means) 20 for up / down bending operation is rotatably supported on the sub operation portion 17. In addition, the air / water supply operation button 2 is provided on the side surface of the main operation unit 16.
1, a suction operation button 22 and the like are provided.

Next, the detailed structure of the bending mechanism of the endoscope 1 of the present embodiment will be described with reference to FIGS. 2 and 3. As shown in FIG. 2, a plurality of substantially cylindrical first bending pieces (joint pieces) 24 are rotatably connected to the first bending portion 13 of the bending portion 6. Further, a plurality of substantially cylindrical second bending pieces (joint pieces) 25 are rotatably connected to the second bending portion 14, respectively. The first bending portion 13
The first bending piece 24 and the second bending piece 25 of the second bending portion 14 are covered with a curved blade (not shown) in which a thin wire or the like is braided in a tubular shape on the outer peripheral surface of the second bending piece 25. A curved rubber 26 is watertightly covered on the outer peripheral surface to form an integral bending unit.

Further, the first bending portion 13 and the second bending portion 14 of the bending portion 6 are provided with two first vertical bending operations for pulling the bending portion 6 from the distal end side and bending the bending portion 6 in the vertical direction. Wire 27 (first upward / downward bending operation wire 27 in the UP direction and first upward / downward bending operation wire 2 in the DOWN direction)
7) and two first left / right bending operation wires 28 for bending in the left / right direction (first left / right bending operation wire 27 in the LEFT direction and first left / right bending operation wire 27 in the RIGHT direction), respectively. Has been done. Here, as shown in FIG. 3, the two first vertical bending operation wires 27 are arranged at both upper and lower end positions separated by approximately 180 ° along the circumferential direction of the bending pieces 24, 25. Further, the two first left / right bending operation wires 28 are arranged at the left and right end portions of the bending pieces 24, 25 which are separated from each other by approximately 180 ° in the circumferential direction.

Also, the two first vertical bending operation wires 2
7 and each of the first left and right bending operation wires 28.
The respective tip end portions of are fixed to the first bending piece 24a at the most distal end position in the first bending portion 13. Where 2
Each tip fixing portion of the first vertical bending operation wire 27 of the book is 180 ° along the circumferential direction of the first bending piece 24a at the most distal position.
It is arranged at the upper and lower end positions apart from each other. Furthermore, 2
Each tip fixing portion of the first left / right bending operation wire 28 of the book is 180 ° along the circumferential direction of the first bending piece 24a at the most distal position.
It is located at both left and right ends.

Further, as shown in FIG. 3, each first portion of the bending portion 6 is formed.
Four cylindrical first wire guides 30 are arranged at approximately 90 ° intervals on the inner peripheral surfaces of the bending piece 24 and each second bending portion 14, and are fixed by brazing or the like. The two first vertical bending operation wires 27 and the two first horizontal bending operation wires 28 are axially movably inserted in the respective first wire guides 30.

Further, the proximal end side of the two first vertical bending operation wires 27 and the proximal end side of the two first horizontal bending operation wires 28 are the flexible tube portion 7 of the insertion section 2. Pass through
It is extended to the operation unit 3 side on the hand side. Here, in the flexible tube portion 7 of the insertion portion 2, four first coils 31 in which wire is spirally wound are arranged. Then, the two first vertical bending operation wires 27 and the two first horizontal bending operation wires 28 are inserted into the respective first coils 31. As a result, the four bending operation wires 27 and 28 are provided inside the flexible tube portion 7 as shown in FIG. 3, for example, a CCD cable 36 and two illumination light guide fibers 37. It is designed to smoothly move forward and backward without being affected by the air / water supply channel 38 and the channel tube 32.

Also, the two first vertical bending operation wires 2
The base end portions of 7 are the first vertical bending operation knob 1 of the main operation portion 16.
8 and a cylindrical member (not shown) provided coaxially. Then, the first vertical bending operation wire 27 can be pulled by rotating the first vertical bending operation knob 18.

Similarly, the base ends of the two first left / right bending operation wires 28 are connected to a cylindrical member (not shown) provided coaxially with the first left / right bending operation knob 19 of the main operation portion 16. There is. Then, the first left / right bending operation wire 28 can be pulled by rotating the first left / right bending operation knob 19.

Here, for example, the first vertical bending operation knob 18
The first up-and-down bending operation wire 27 in the UP direction is pulled by the turning operation of. At this time, since the first up-and-down bending operation wire 27 passes through the first bending piece 24 and the first wire guides 30 in the second bending portion 14, the first bending portion 13 and the second bending portion 14 are not moved. Can be activated at the same time. Then, with the pulling operation of the first up-and-down bending operation wire 27 in the UP direction, the second bending pieces 25 of the second bending portion 14 and the first bending pieces 24 of the first bending portion 13 are sequentially moved from the hand side to the bending pieces. U to the position where the shoulder opening 33 contacts
It can be rotated in the P direction. In this way, the curved portion 6
By simultaneously operating the first bending portion 13 and the second bending portion 14, it is possible to sufficiently secure the total axial length of the bending portion 6 and form a large curved shape in the UP direction. At this time, a desired bending angle in the UP direction can be adjusted by the amount of pulling of the first vertical bending operation wire 27 in the UP direction.

Further, the first vertical bending operation wire 27 in the DOWN direction can be pulled by rotating the first vertical bending operation knob 18 in the opposite direction. This makes the first
The bending portion 13 and the second bending portion 14 can be operated at the same time to sufficiently secure the total axial length of the bending portion 6 to form a large DOWN direction curved shape. At this time, the desired bending angle in the DOWN direction can be adjusted by the amount of pulling of the first vertical bending operation wire 27 in the DOWN direction.

The first left / right bending operation wire 2 in the LEFT direction is rotated by rotating the first left / right bending operation knob 19.
8 is pulled, or when the first left / right bending operation wire 28 in the RIGHT direction is pulled by rotating the first left / right bending operation knob 19 in the opposite direction, the first bending portion 13 and the second bending portion 14 are similarly moved. Can be activated simultaneously. As a result, the first bending portion 13 and the second bending portion 14 can be operated at the same time, and the total axial length of the bending portion 6 can be sufficiently secured to form a large curved shape in the LEFT direction or the RIGHT direction. it can. At this time, the bending angle in the desired bending direction can be adjusted by the pulling amount of the first left / right bending operation wire 28 in the LEFT direction or the RIGHT direction.

In addition, the second end of the second bending portion 14 at the most distal position
Two second vertical bending operation wires 29 (UP) for pulling and bending the second bending portion 14 are provided on the bending piece 25a.
The tip ends of the second vertical bending operation wire 29 in the direction and the second vertical bending operation wire 29 in the DOWN direction are fixed. Here, the two second vertical bending operation wires 2
The respective tip fixing portions 9 are arranged at both upper and lower end positions which are 180 ° apart from each other along the circumferential direction of the second bending piece 25a at the most distal position.

Further, as shown in FIG. 3, the second bending portion 14
Two cylindrical second wire guides 34 through which the two second vertical bending operation wires 29 are inserted are fixed to the inner peripheral surface of only each second bending piece 25. And 2
The second vertical bending operation wire 29 of the book is inserted into each of the second wire guides 34 so as to be movable in the axial direction.

Further, the two second vertical bending operation wires 2
Each base end side of 9 passes through the flexible tube section 7 of the insertion section 2 and extends to the operation section 3 side on the proximal side. Here, in the flexible tube portion 7 of the insertion portion 2, two cylindrical second coils 35 through which the two second vertical bending operation wires 29 are respectively inserted are arranged. The two second vertical bending operation wires 29 are inserted into the respective second coils 35.

Further, the base end portions of the two second vertical bending operation wires 29 are respectively extended to the operation portion 3 side on the hand side. Here, the respective base ends of the two second vertical bending operation wires 29 are connected to a cylindrical member (not shown) provided coaxially with the second vertical bending operation knob 20 of the sub operation portion 17. Then, by rotating the second vertical bending operation knob 20, the second vertical bending operation wire 29 can be pulled.

Further, since the second vertical bending operation wire 29 passes through the second wire guide 34 of each second bending piece 25 of the second bending portion 14, the UP operation is performed by operating the second vertical bending operation knob 20. Direction, or the DOWN direction of the second up-and-down bending operation wire 29, it is possible to operate only the second bending portion 14. This allows the second
By operating only the second bending portion 14 when operating the up-down bending operation knob 20, it is possible to realize a curved shape with a small turning effect.

Further, each second bending piece 2 of the second bending portion 14
On the inner peripheral surface of 5, a first wire guide 30 for a first up / down bending operation wire 27 for bending the entire bending portion 6 in the up / down direction, and a second up / down bending operation wire for operating only the second bending portion 14 are provided. Since the second wire guide 34 for 29 is provided adjacent to the second wire guide 34, it is possible to minimize the deviation in the bending direction when each bending operation is performed.

Therefore, the following effects can be obtained with the above-mentioned structure. That is, in the endoscope 1 according to the present embodiment, when the first vertical bending operation knob 18 and the first horizontal bending operation knob 19 of the operation portion 3 are operated, the first bending portion 13 on the distal end side of the insertion portion 2 and the first bending portion 13 are operated. The second bending portion 14 behind the first bending portion 13
By simultaneously operating and, it is possible to sufficiently secure the total axial length of the bending portion 6 and form a large curved shape. In addition, the second vertical bending operation knob 2
By operating only the second bending portion 14 at the time of operation of 0, it is possible to realize a curved shape with a small turning effect.
As a result, the total axial length of the bending portion 6 is sufficiently secured to improve the insertion performance of the endoscope insertion portion 2, and a curved shape that makes a small turn is realized, thereby achieving both observation and treatment performance. An excellent endoscope can be provided.

Next, a method of using the endoscope 1 of this embodiment for actual endoscopic examination and treatment will be described with reference to FIGS. 4 and 5.
Will be described with reference to. FIG. 4 shows that while the endoscope 1 is being inserted into the large intestine H, the insertion portion 2 is twisted while hooking the distal end portion 5 of the endoscope 1 to the spleen curved portion 39 of the large intestine H to form the S-shaped colon 40. This shows a state in which the formed deflection 41 is about to be released.

Here, the entire bending portion 6 (the first bending portion 13 and the second bending portion 1) is moved by the first vertical bending operation knob 18.
By bending 4) in the UP direction, a large bending radius R
Can be formed. Therefore, the distal end portion 5 of the endoscope 1 can be easily hooked on the splenic flexure portion 39. This makes it easier to release the flexure 41. Then, by releasing the flexure 41, the insertion work of the endoscope 1 into a deeper portion can be facilitated.

FIG. 5 shows a state in which the inside of the large intestine H is observed with the endoscope 1. Generally, many folds 42 are formed in the large intestine H due to anatomical features. And
Observation of the back side of the fold 42 is often difficult with an ordinary endoscope. In such a situation, the endoscope 1 of the present embodiment
Then, after bending the entire bending portion 6 in the UP direction by the first up-down bending operation knob 18, by bending the second bending portion 14 in the DOWN direction by the second up-down bending operation knob 20, the entire bending portion 6 is bent. The shape is S-shaped as shown in FIG. 5, and it is possible to provide a curved shape with a small turning effect. As a result, it is possible to easily perform an endoscopic observation of the back side of the fold 42, which has been difficult in the past. The effect can be sufficiently exerted not only in endoscopic observation but also in treatment.

Further, when the endoscope 1 in which the angle operation of the bending portion 6 is frequently performed is inserted, the first up-down bending operation knob 18 and the first left-right bending operation knob 1 required for the insertion operation.
9 is a main operation section 16 close to the grip section 15 for the operator to hold 9.
Second up-and-down bending operation knob 20 that is placed in the
By arranging in the sub operation unit 17 which is normally out of reach, the operator can operate more comfortably.

Next, the first treatment method using the endoscope 1 of the present embodiment will be described with reference to FIGS. 6 (A) to 6 (C) and FIG. 7. When a malignant tumor 43 is found during observation with the endoscope 1 of the present embodiment, the local injection needle 44 is inserted into the body through the channel 11 of the endoscope 1.
Then, as shown in FIG. 6A, physiological saline is injected under the malignant tumor 43 with a local injection needle 44. As a result, the submucosal layer and the proper muscle layer are separated.

Further, as shown in FIG. 6B, an external channel 45 is attached to the outer peripheral surface of the insertion portion 2 of the endoscope 1 in advance. A snare device 46 is inserted into the external channel 45. The ring portion 47, which is made of a material having a high thermal conductivity and protrudes from the snare device 46, is passed through the insertion portion 2 in advance.

Then, the threaded clip 48 is projected from the channel 11 of the endoscope 1. Then, while avoiding the malignant tumor 43, clipping is performed by a threaded clip 48 in the vicinity thereof. The same operation is repeated, and as shown in FIG. 6C, clipping with the threaded clip 48 is performed around the malignant tumor 43 four times at equal intervals.

Next, the snare device 46, which has been passed through the insertion portion 2 in advance, is projected forward. At this time, while increasing the diameter of the ring portion 47, the clip with thread 4
As shown in FIG. 7, the ring portion 47 is hooked around the entire circumference of the malignant tumor 43 by using the guide 8 as a guide. After that, the binding of the ring portion 47 and the energization of the high frequency current are simultaneously performed to excise the malignant tumor 43.

In this treatment method, since the ring portion 47 can be snareed around the entire circumference of the malignant tumor 43 with the threaded clip 48 as a guide, the entire excision range set by the clipping of the threaded clip 48 can be surely performed. Can be removed. Therefore, it is possible to collectively remove a larger lesion site. Further, since the ring portion 47 is locked by the clip 48 when the ring portion 47 of the snare device 46 is tightly bound, the ring portion 47 does not slip on the surface of the living tissue.

The external channel 4 is used as in this treatment method.
5 does not have the snare device 46 inserted therethrough, but has a 2-channel configuration different from that of the endoscope 1 of the first embodiment (see FIGS. 1 to 7) as in the modification shown in FIG. Endoscope 4
9 may be used. In this modification, a two-channel endoscope 49 is provided. Further, a transparent cap 50 is attached to the tip portion 5 of the two-channel endoscope 49. A projecting portion 53 is projected on the inner peripheral surface of the tip portion of the transparent cap 50.

Then, the two-channel endoscope 4 of the present modification example.
When using 9, the snare device 46 is inserted through the first channel 51 of the two-channel endoscope 49, and the ring portion 47 is brought into contact with the protrusion 53 of the transparent cap 50 in advance. In this state, the threaded clip 48 is projected from the second channel 52 of the two-channel endoscope 49. After that, the malignant tumor 43 is excised by the same operation as that of the endoscope 1 of the first embodiment. Thereby, also in this modification, the same effect as that of the endoscope 1 of the first embodiment can be obtained.

Further, FIGS. 9A to 9D show the second embodiment of the present invention.
FIG. This embodiment is a second embodiment of the endoscope 1 of the first embodiment (see FIGS. 1 to 7).
It shows the treatment method of. In this embodiment mode, FIG.
As shown in (A), a transparent cap 50 is attached to the distal end portion 5 of the endoscope 1 in advance. A ring-shaped tightening tool 54 made of an elastic material such as rubber is provided on the outer peripheral surface of the transparent cap 50.

A ring-shaped protrusion 53 is provided on the inner peripheral surface of the front end of the transparent cap 50. The ring portion 47 of the snare device 46 protruding from the channel 11 is set in the transparent cap 50 in a state of abutting the protrusion 53 in advance.

When treating the malignant tumor 43, physiological saline is injected under the malignant tumor 43 with a local injection needle 44 (see FIG. 6 (A)) so that the submucosa and the muscular propria are separated. Peel off. Then, the tip of the transparent cap 50 is pressed around the malignant tumor 43, and suction is performed using the channel 11.

At this time, since the submucosal layer and the proper muscle layer have already been separated, only the submucosal layer is accommodated in the transparent cap 50 as shown in FIG. 9 (B). In this state, the fixing device 55 attached to the tightening tool 54 (see FIG.
(See (A)), and tighten the fastener 54 that is an elastic body.
The fastener 54 is hung over the entire circumference of the malignant tumor 43 by pushing out toward the front of the transparent cap 50. As a result, the root portion of the lesion site of the malignant tumor 43 sucked and lifted in the transparent cap 50 can be sufficiently tightened by the elasticity of the tightening tool 54.

Then, as shown in FIG. 9 (C), after the ring portion 47 of the snare device 46 is hung over the fastener 54 which has fastened the root portion of the lesion site of the malignant tumor 43, tight binding and high frequency current Energize at the same time, Fig. 9
The malignant tumor 43 is excised as shown in (D).

In this treatment method, since the elastic fastener 54 is used to tighten the lower portion of the snare before the snare device 46 excises the lesion site, the snare device 46 uses the ring part 47 to snare the lesion site. It is possible to occlude the blood vessel downstream of the bleeding site that occurs when the ablation is performed. Therefore, a safe treatment with less bleeding can be provided.

In this treatment method, the blood vessel downstream of the bleeding site, which is generated when the lesion site is excised, was closed by the tightening tool 54 made of an elastic material. A device may be used.

Further, FIGS. 10A to 10D show a third embodiment of the present invention. This embodiment is shown in FIG.
Third using the 2-channel endoscope 49 shown in 0 (A)
It shows the treatment method of. In the present treatment method, a hooking device 56 having an L-shaped tip is loaded in the first channel (not shown) of the two-channel endoscope 49. This L
The character-shaped hooking device 56 is inserted through the first channel from the tip portion 5 in advance.

When treating the malignant tumor 43, as shown in FIG.
As shown in (A), the needle portion 57 of the hooking device 56 is punctured into the living tissue near the malignant tumor 43 while the tip of the endoscope 49 is inclined. At this time, the hooking device 56
The needle portion 57 of the is protruded to the outside of the large intestine wall while avoiding the malignant tumor 43. Then, after straightening the endoscope 49, the endoscope 49 is pulled up as it is.

Next, as shown in FIG.
The tying device 58 is projected from the second channel (not shown) in FIG. At this time, while securing a sufficient distance from the malignant tumor 43, a device 58 for connecting the lower part of the hoisted colon wall.
Bonding is done at the tying part 59.

After that, the knotting device 58 remaining in the second channel is switched to the clipping device. And FIG.
As shown in 0 (C), clipping is performed on the upper portion of the knotted portion 59 by using a required number of clips 60.

Finally, as shown in FIG. 10D, the clip device of the second channel is switched to the snare device 46. The snare device 4 is placed above the clip 60.
Tightening of the ring portion 47 of 6 and energization of a high frequency current are simultaneously performed to excise the malignant tumor 43.

In this treatment method, perforation of the large intestine wall is prevented in advance by the ligation device 58, and bleeding can be prevented by using clipping together. This treatment method makes it possible to provide a safe and reliable full-thickness resection of the large intestine.

11A to 11C show a fourth embodiment of the present invention. This embodiment is the third
10 shows a modification of the treatment method (see FIGS. 10A to 10D). In this modified example, as shown in FIG. 11A, a lifting device 61 different from the third treatment method is used.

A lifting portion 63 is rotatably connected to the tip of the lifting device 61 of this modification via a pin 62. A conical puncture portion 64 is formed at the tip of the lifting portion 63. Usually, the lifting portion 63 is arranged parallel to the sheath portion 65, that is, coaxially with the different electrode of the electromagnet, as shown in FIG.

As shown in FIG. 11B, when lifting the entire large intestine wall in order to treat the malignant tumor 43, the lifting device 61 of this modification is projected from the first channel (not shown) of the endoscope 49. Let The lifting device 61 is pressed against the large intestine wall while avoiding the malignant tumor 43,
It is made to project outside the large intestine wall by 4.

In this state, the relationship between the sheath portion 65 and the suspension portion 63 of the suspension device 61 is electrically converted from the different electrode to the same electrode, so that the suspension portion 63 is covered by the sheath portion 63 as shown in FIG. 11C. Move to a position perpendicular to 65. At this time, since the lifting portion 63 locks the large intestine wall, sufficient lifting is possible. The treatment method is the same as the above-mentioned third treatment method.

FIG. 12 shows a fifth embodiment of the present invention. In this embodiment, the treatment tool used in the two-channel endoscope 49 is modified as follows.

That is, in the present embodiment, the cutting device 66 shown in FIG. 12 is used. The cutting device 66 includes a knife portion 6 having an elliptical tip and a thermally conductive material.
7 is provided.

In the present embodiment, the excision device is used by the above-mentioned first treatment method in a state where physiological saline is injected, the submucosal layer and the proper muscle layer are separated, and the periphery of the malignant tumor 43 is precut. By excising the lesion site of the malignant tumor 43 with the knife portion 67 of 66, more reliable and wide-range excision becomes possible.

FIG. 13 shows a sixth embodiment of the present invention. In this embodiment, the method of using the treatment tool used in the two-channel endoscope 49 is changed as follows.

That is, in this embodiment, as shown in FIG. 13, the snare device 46 is inserted into the first channel 51 of the two-channel endoscope 49, and the tip of the second channel 52 is formed into an S shape. Guide device 6 having stop 68
9 is inserted.

In this embodiment, the snare device 46
The guide device 69 is used as follows when expanding the ring portion 47 of the. First, the locking portion 68 of the guide device 69 is hooked on the ring portion 47. In this state, the second channel 5
The size of the ring portion 47 of the snare device 46 is arbitrarily set by changing the amount of protrusion of the guide device 69 that is projected from 2 to the front of the tip portion 5.

In this method, the size of the ring portion 47 of the snare device 46 can be more positively set by the guide device 69, so that a larger loop shape can be formed as compared with the conventional case. Therefore, it is effective in excising a larger lesion site.

Further, FIGS. 14A and 14B show a seventh embodiment of the present invention. In this embodiment, a transparent hood 70 is attached to the distal end portion 5 of the endoscope 1 of the first embodiment (see FIGS. 1 to 7).

As shown in FIG. 14A, the transparent hood 70 is provided with a substantially cylindrical hood body 71 made of an elastic body. A ring-shaped sliding portion accommodating groove 71a is formed at the front end of the hood body 71. A substantially cylindrical movable cylindrical body 72 is accommodated in the sliding portion accommodation groove 71a so as to be capable of projecting and retracting forward with respect to the hood body 71.

Further, the hood body 71 has a sliding portion accommodating groove 7
A wire insertion hole 71b that communicates with the rear end of 1a is formed. Further, the front end of the guide tube 74 communicating with the wire insertion hole 71b is connected to the rear end of the hood body 71. The rear end portion of the guide tube 74 extends toward the operation portion 3 side of the endoscope 1 on the proximal side.

The distal end of the operation wire 73 is fixed to the rear end of the movable cylinder 72. This operation wire 7
3 is a guide tube 74 through the wire insertion hole 71b.
It is inserted inside.

Further, the transparent hood 70 is fixed to the distal end portion 5 of the endoscope 1 by tightening the hood body 71 made of an elastic body. Further, the movable cylinder 72 is the hood body 7
It is possible to move back and forth with respect to 1 by pulling the operation wire 73. The movable cylinder 72 may be moved back and forth using air pressure.

Next, the operation of the present embodiment having the above structure will be described. In the present embodiment, with the transparent hood 70 attached to the endoscope 1, the movable tubular body 72 is projected toward the distal end side as shown by the phantom line in FIG.
As shown in FIG. 14B, the movable tubular body 72 and the hood body 7
A ring-shaped concave portion 76 is formed between the concave portion 76 and the concave portion 1. The fold 42 of the large intestine can be positively turned by hooking the fold 42 of the large intestine in the concave portion 76 or by sandwiching the fold 42 of the large intestine between the movable cylindrical body 72 and the hood body 71.

Therefore, in the present embodiment, as described above,
The back side of the large intestine fold 42, which is generally difficult to observe, by rolling the large intestine fold 42 in a state where the large intestine fold 42 is held by the recess 76 between the movable tubular body 72 of the transparent hood 70 and the hood body 71. Observation of the polyp 75 in the vicinity becomes easy.

Further, as in the first modification of the transparent hood 70 of the seventh embodiment shown in FIG. 15A, a protrusion 77 is provided on the tip side of the transparent hood 70, and the protrusion 77 folds the hood. 42 may be hooked. Even in this case, the same effect as that of the transparent hood 70 of the seventh embodiment can be obtained.

Further, as in the second modification of the transparent hood 70 of the seventh embodiment shown in FIG. 15B, a balloon 78 is provided on the distal end side of the transparent hood 70.
Alternatively, the pleats 42 may be hooked by means of 8. Even in this case, the same effect as that of the transparent hood 70 of the seventh embodiment can be obtained. Moreover, the outer diameter can be minimized during normal insertion or if the balloon 78 is not inflated.

16 and 17 show the eighth embodiment of the present invention.
FIG. In this embodiment, FIG.
As shown in FIG. 6, the first embodiment (see FIGS. 1 to 7)
The T-bar housing groove 80 is formed in the distal end portion 5 of the endoscope 1. A T-shaped T-bar 79 is housed in the T-bar housing groove 80 so as to project and retract. Further, the tip end of an operation wire (not shown) is fixed to the T bar 79. The rear end portion of this operation wire extends to the side of the operation portion 3 on the proximal side of the endoscope 1.

When the endoscope 1 of the present embodiment is used, the T-bar 79 is projected forward from the T-bar housing groove 80 of the distal end portion 5 as shown in FIG. It can be pressed down. for that reason,
In this case, since the polyp 75 can be tilted to the front side of the field of view of the endoscope 1, the polyp 7 that is generally difficult to observe
The back (back side) portion of 5 becomes easy to observe.

When the endoscope 1 is inserted, the T-bar 79 is housed in the housing groove 80, so that the T-bar 79 does not interfere with the body wall when the endoscope 1 is inserted. There is no risk of damage.

18A to 18C show the ninth embodiment of the present invention. In the present embodiment, as shown in FIG. 18A, the imaging unit 83 is embedded in the central portion of the tip portion of the two-channel endoscope 49. As shown in FIG. 18B, the image pickup unit 83 includes an observation cover lens 8, a plurality of optical lenses 81 that are stacked,
It is composed of a CCD 82 and the like. Further, a flexible CCD cable 36 for transmitting an electric signal is connected to the rear of the image pickup unit 83. An O-ring 89 is fitted in the insertion hole of the CCD cable 36 in the distal end forming portion 90 of the endoscope 49. The O-ring 89 is pressed against the outer peripheral surface of the CCD cable 36 and sealed to ensure watertightness between the inside and the outside of the two-channel endoscope 49.

Further, the support frame 8 of the image pickup unit 83
Rotating shafts 84 are provided on both sides of 3a, respectively. The image pickup unit 83 is rotatably supported by the rotary shaft 84 with respect to the distal end portion 5. further,
The tip of the raising wire 85 is attached to the support frame 83a of the imaging unit 83. The rear end portion of the raising wire 85 extends to the operation portion side of the endoscope 49 on the near side.

Further, at the tip of the endoscope 49, the first channel 51, the second channel 51
The channels 52 are arranged to face each other. Here, the first channel 5 is provided on the outer peripheral surface of the imaging unit 83.
The first guide groove 8 is provided on the side facing the first and second channels 52.
7 and a second guide groove 88 are provided respectively.

Then, by pulling the raising wire 85 of the image pickup unit 83, the image pickup unit 83
Rotates about the rotary shaft 84, and the viewing direction can be switched. At this time, as shown in FIG. 18C, the treatment tool 86 inserted through the second channel 52 is extended along the second guide groove 88 provided on the outer peripheral surface of the imaging unit 83,
It projects in the visual field direction of the switched imaging unit 83.

Therefore, in this embodiment, since the guide unit for guiding the treatment instrument 86 is provided in the image pickup unit 83 having an optical system, the visual field of the image pickup unit 83 is switched and the treatment instrument 8 is operated.
Since 6 inductions can be achieved at the same time, more efficient observation / treatment is possible.

19 and 20 show the first embodiment of the present invention.
0 shows an embodiment of No. 0. In the present embodiment, as shown in FIG. 19, 4 around the observation cover lens 8 arranged at the central portion of the distal end portion 5 of the endoscope 1 of the first embodiment (see FIGS. 1 to 7). One channel 91a-9
1d is provided.

Therefore, according to the endoscope 1 of the present embodiment, the treatment instrument 92 guided from each of the four channels 91a to 91d is within the observation image P of the observation cover lens 8 as shown in FIG. It is displayed in a state of being projected from the directions of the four corners toward the central portion. Therefore, it is possible to guide the treatment instrument 92 by selectively using one of the four channels 91a to 91d, whichever allows the treatment instrument 92 to approach the lesion site most easily, depending on the position of the lesion site. As a result, the selection range of the approach of the treatment instrument 92 to the lesion site is expanded, so that the treatment method of the endoscope 1 excellent in workability in which the approach of the treatment instrument 92 to the lesion site is easily performed can be provided.

In the endoscope 1 of this embodiment, the first
The first bending portion 13 and the second bending portion 13 are formed by the first bending operation means including the up / down bending operation knob 18 and the first left / right bending operation knob 19.
The configuration has been described in which the bending portion 14 is driven and only the second bending portion 14 is driven by the second bending operation means that is the second up-down bending operation knob 20, but the invention is not limited to this. That is, the present invention aims to achieve both large and small curved shapes, and in order to achieve this purpose, the first bending portion and the first bending portion can be formed by the first bending operation means depending on the operator's preference and organ features. It is also possible to drive the two bending portions and drive only the first bending portion according to the second bending operation procedure. Further, the first bending portion and the second bending portion may be driven by the first bending operation procedure, and the first bending portion or the second bending portion may be selectively driven by the second bending operation means.

Furthermore, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention. Next, other characteristic technical matters of the present application will be additionally described as follows. (Additional Item 1) A first bending portion and a second bending portion, which are configured by rotatably connecting a plurality of joint pieces to the distal end side of the elongated insertion portion, and are connected to the proximal end side of the insertion portion, In an endoscope including a holding section having an operation section capable of performing a bending operation of the first bending section and the second bending section, the first bending section is arranged on the distal side of the second bending section. And first
An endoscope provided with a first bending operation means for driving the bending portion and the second bending portion simultaneously and a second bending operation means for driving only the second bending portion.

(Additional Item 2) The first bending portion and the second bending portion, which are formed by rotatably connecting a plurality of joint pieces to the distal end side of the elongated insertion portion, and are connected to the proximal end side of the insertion portion. However, in the endoscope including the grasping portion having the operation portion capable of performing the bending operation of the first bending portion and the second bending portion, the first bending portion may be located closer to the tip side than the second bending portion. The first bending section and the second bending section that are driven simultaneously.
An endoscope provided with a bending operation means and a second bending operation means for driving only the first bending portion.

(Additional Item 3) The first bending portion and the second bending portion, which are formed by rotatably connecting a plurality of joint pieces to the distal end side of the elongated insertion portion, and are connected to the proximal end side of the insertion portion. However, in the endoscope including the grasping portion having the operation portion capable of performing the bending operation of the first bending portion and the second bending portion, the first bending portion may be located closer to the tip side than the second bending portion. The first bending section and the second bending section that are driven simultaneously.
An endoscope comprising a bending operation means, and a second bending operation means for selectively operating the first bending portion and the second bending portion.

(Additional Item 4) For the purpose of inserting the large intestine,
The endoscope according to appendices 1, 2 and 3.

(Additional Item 5) The additional bending items 1, 2 and 3 are characterized in that the first bending operation means is arranged in the vicinity of the grip portion and the second bending operation portion is arranged more distally than the grip portion. The endoscope described in.

(Additional Item 6) In an endoscope having a pulling wire that bends in two or more same bending directions, a means for guiding the pulling wire is arranged at least adjacent to the bending tube. The endoscope according to additional items 1 to 5.

(Additional Item 7) An image pickup unit including a solid-state image pickup element built in a distal end portion of an endoscope is rotatably arranged, and a treatment instrument insertion channel is provided on both sides of the image pickup unit. An endoscope in which a guide groove is provided in the imaging unit.

(Prior Art of Supplementary Notes 1 to 6) Insertion of an endoscope in colonoscopy is such that the anatomical complexity of the large intestine and the running and length of the intestine vary widely among individuals. Therefore, it is said that it is difficult to learn the technique.

In such an environment, the operator's insertion technique has made progress, and at present, a technique such as a light turn shortening technique of inserting it while hooking the folds of the intestine has been developed. In addition, the endoscope is inserted along the lumen and the distal end of the endoscope is hooked at the bent portion to release the loop of the endoscope insertion portion forming an arc and facilitate the insertion into the deep portion. And so on. To accommodate such a procedure, in an endoscope inserted into the large intestine, the axial length of the bending portion that directs the distal end portion in a desired direction is
Some length is needed.

On the other hand, the large intestine has many folds due to its anatomical characteristics, and in order to observe and treat the back side of the fold, the curved portion of the endoscope is required to have a small turning effect. It

As a bending mechanism that makes a small turn, P200
No. 1-232166, a first bending portion in which a plurality of joint pieces are rotatably connected to the distal end side of an elongated insertion portion, and a second bending portion connected to the rear side of the first bending portion. It has been devised that it has two curves and the axial dimension of the second bending section is smaller than the axial dimension of the first bending section.

(Problems to be Solved by Additional Items 1 to 6)
However, if a curving mechanism with a small turning effect is adopted, observation and treatment of the back side of the folds will be easier, while in the insertion procedure, with the length of the bending portion of the present invention, the folds can be separated and an endoscope with an arc drawn can be inserted. The length is insufficient when hooked on the bend to release the loop of the part.

As a means for improving the insertability of the endoscope, it is conceivable to lengthen the axial length of the first bending portion, but in this case, the shape of the bending becomes large and the small turning becomes ineffective. .

That is, at present, it has been difficult to achieve both insertion performance and observation / treatment performance by improving the bending mechanism.

(Objects of Supplementary Items 1 to 6) The present invention has been made in view of the above circumstances, and the bending portion can be formed by simultaneously operating the first bending portion and the second bending portion by the first bending operation mechanism. In addition to securing a sufficient total axial length in the above, by operating either the first bending portion or the second bending portion by the second bending operation mechanism, a bending shape with a small turning effect is realized, and insertion performance and observation An object is to provide an endoscope excellent in both treatment performance.

(Effects of Supplementary Items 1 to 6) In this embodiment, in the large intestine endoscope, both the axial length of the bending portion and the curved shape with a small turning are compatible to insert the endoscope. It is possible to provide an endoscope that improves performance and observation / treatment performance at the same time.

(Prior Art of Supplementary Note 7) As a means for guiding a treatment instrument inserted from a treatment channel of an endoscope in a desired direction, a treatment instrument installed at a distal end portion of the endoscope is raised. The mechanism is known.

(Problem to be Solved by Appendix 7) However, when the treatment instrument raising mechanism guides the treatment instrument in a desired direction, the observation direction of the endoscope does not change, and therefore the field of view of the endoscopic image is not changed. At, the treatment tool moves from the center of the visual field to the distal end.

That is, when the treatment is performed, the treatment state cannot be captured in the central portion of the field of view of the endoscopic image, and it may be difficult for the operator to perform the treatment.

(Object of Supplementary Note 7) The present invention has been made in view of the above circumstances, in which an imaging unit for controlling observation is rotatably arranged and a guide groove for a treatment instrument is provided in the imaging unit. Therefore, it is an object of the present invention to provide an environment in which an operator can easily perform treatment.

(Effect of Additional Item 7) In this embodiment,
In the endoscopic treatment, by providing the guide groove of the treatment tool in the imaging unit, it is possible to provide an endoscope that can simultaneously perform the work of guiding the treatment tool in a desired direction and the work of directing the visual field in that direction. It is possible.

[0113]

According to the first aspect of the present invention, two curved portions formed by rotatably connecting a plurality of joint pieces to the distal end side of the elongated insertion portion are provided along the axial direction of the insertion portion. First bending operation means for arranging in parallel and simultaneously driving a first bending portion arranged on the distal end side of the insertion portion and a second bending portion arranged behind the first bending portion, and at least a first bending portion Since the second bending operation means for driving only one of the bending portion and the second bending portion is provided in the operation portion connected to the proximal end side of the insertion portion, the total axial length of the bending portion can be sufficiently increased. It is possible to provide an endoscope that is excellent in both observation and treatment performance by ensuring and improving the insertion performance of the endoscope insertion portion and realizing a curved shape that makes a small turn.

According to the second aspect of the present invention, it is possible to selectively switch the first bending portion and the second bending portion to be operated when the second bending operation means is operated by operating the switching operation means.

[Brief description of drawings]

FIG. 1 is a perspective view of a colonoscope showing a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a main part showing an internal structure of a bending portion in the endoscope according to the first embodiment.

FIG. 3 is a transverse cross-sectional view showing the internal configuration of the bending portion of the insertion portion in the endoscope of the first embodiment.

FIG. 4 is a schematic configuration diagram showing a state in which the distal end portion of the endoscope is hooked on the spleen curved portion of the large intestine while the endoscope of the first embodiment is being inserted into the large intestine.

FIG. 5 is a schematic configuration diagram showing a state of observing the inside of the large intestine with the endoscope according to the first embodiment.

FIG. 6 shows an example of treatment in the endoscope according to the first embodiment, and (A) is a perspective view showing a state where physiological saline is injected under a malignant tumor with a local injection needle; FIG. 9B is a perspective view showing a state where clipping is performed by a threaded clip in the vicinity of a malignant tumor, and FIG. 9C is a perspective view showing a state where clipping is performed by a threaded clip around the malignant tumor four times at equal intervals.

FIG. 7 is a perspective view showing a state in which the malignant tumor is resected by hanging the ring part around the entire circumference of the malignant tumor and simultaneously binding the ring part and conducting high-frequency current.

FIG. 8 is a perspective view showing a state in which a malignant tumor is resected by the endoscope according to the modified example of the first embodiment.

FIG. 9 shows a second embodiment of the present invention,
(A) is a perspective view showing a state in which the tip of the transparent cap is brought close to the periphery of the malignant tumor, and (B) is a part of the lesion part of the malignant tumor which is sucked and lifted into the transparent cap, and is clamped with a fastener. FIG. 3C is a perspective view showing a partial cross-section of the state, in which the root portion of the lesion site of the malignant tumor is bound by the ring portion of the snare device and the high-frequency current is simultaneously applied. FIG. 1D is a perspective view showing a state in which a malignant tumor is removed.

FIG. 10 shows a third embodiment of the present invention,
(A) is a perspective view showing a state in which a needle part of a hooking device is punctured into a living tissue in the vicinity of a malignant tumor, and (B) is tightly bound with a knotting part of a knotting device that connects the lower part of the suspended colon wall FIG. 3C is a perspective view showing a state in which the malignant tumor is removed, FIG. 6C is a perspective view showing a state in which the upper portion of the knot is clipped using a plurality of clips, and FIG.

FIG. 11 shows a fourth embodiment of the present invention,
(A) is a perspective view showing a lifting device, (B) is a perspective view showing a state in which the lifting device is pressed against the large intestine wall and is projected outside the large intestine wall by a puncture part, and (C) is for treating a malignant tumor. The side view which shows the state which lifted the whole large intestine wall.

FIG. 12 is a perspective view showing a usage state of a cutting device in a two-channel endoscope according to a fifth embodiment of the present invention.

FIG. 13 is a perspective view showing a usage state of a treatment tool used in a two-channel endoscope according to a sixth embodiment of the present invention.

FIG. 14 shows a seventh embodiment of the present invention,
(A) is a partial cross-sectional side view showing a state in which a transparent hood is attached to the distal end of the endoscope, and (B) is a ring-shaped recess between the movable cylinder and the hood body, showing the large intestine. The side view which shows the state which has rolled up the fold.

FIG. 15 (A) is a side view showing a first modification of the transparent hood of the seventh embodiment in a partial cross section, and FIG. 15 (B) is a second view of the transparent hood of the seventh embodiment. The side view which shows a modification partially in section.

FIG. 16 is a perspective view showing a distal end portion of an endoscope according to an eighth embodiment of the present invention.

FIG. 17 is a side view showing a state in which the front part of the polyp is held down by the T-bar of the endoscope of the eighth embodiment.

FIG. 18 shows a ninth embodiment of the present invention,
(A) is a front view showing the distal end portion of the endoscope, (B) is a vertical cross-sectional view showing the internal structure of the distal end portion of the endoscope, (C) is a vertical cross-sectional view showing the switching state of the visual field direction of the imaging unit. Fig.

FIG. 19 is a perspective view of a distal end portion of an endoscope showing a tenth embodiment of the present invention.

FIG. 20 is a plan view showing an observation image of the endoscope according to the tenth embodiment.

[Explanation of symbols]

2 Insert 3 operation part 13 first bending part 14 second bending part 18 first up-down bending operation knob (first bending operation means) 19 First left / right bending operation knob (first bending operation means) 20 Second up-down bending operation knob (second bending operation means) 24 1st bending piece (joint piece) 25 Second bending piece (joint piece)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hidenobu Kimura             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. (72) Inventor Tatsuya Furukawa             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. (72) Inventor Takatsugu Yamatani             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. (72) Inventor Masaaki Nakazawa             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. (72) Inventor Nobuyuki Matsuura             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. (72) Inventor Hisao Yabe             2-43 Hatagaya, Shibuya-ku, Tokyo Ori             Inside Npus Optical Industry Co., Ltd. F-term (reference) 4C061 AA04 CC06 DD03 FF12 FF40                       FF43 GG14 GG15 HH21 HH33                       HH35 HH57 LL02

Claims (2)

[Claims] 1. A pair of bending portions, each of which is formed by rotatably connecting a plurality of joint pieces, are arranged side by side on the distal end side of the elongated insertion portion along the axial direction of the insertion portion. First bending operation means for simultaneously driving a first bending portion arranged on the distal end side and a second bending portion arranged behind the first bending portion, and at least the first bending portion and the second bending portion. Second drive only one of the parts
An endoscope comprising a bending operation means and an operation portion connected to a proximal end side of the insertion portion. 2. The endoscope according to claim 1, wherein the second bending operation means has a switching operation means for selectively performing an operation of switching between the first bending portion and the second bending portion. .