JP7271948B2 - Forceps-type instrument - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forceps-type treatment instrument for performing treatment such as hemostasis using high-frequency current using an endoscope, for example.

A sheath through which the drive wire is passed, an operation section provided at the proximal end of the sheath, and a treatment section having a pair of forceps pieces provided at the distal end of the sheath are provided, and the drive wire is inserted into the sheath. A forceps-type treatment instrument is used that opens and closes a pair of forceps pieces by sliding them against each other (see, for example, Patent Document 1).

As a sheath used for such a forceps-type treatment instrument, the document discloses a coil sheath formed by tightly winding a metal wire. Such a coil sheath is particularly resistant to compression in the axial direction, and hardly changes in dimensions, as compared with a resin tube. Therefore, in order to close the pair of forceps pieces, the responsiveness when the drive wire is slid with respect to the sheath in the direction in which it is pulled back is good, and the operation force applied by the operation portion is sufficiently applied to the pair of forceps pieces. can be transmitted, and a strong gripping force can be realized by the pair of forceps pieces.

On the other hand, the coil sheath is not as strong in the tension direction as it is in the compression direction, and the responsiveness when the drive wire is slid relative to the sheath in the direction to push it out in order to open the pair of forceps pieces is not necessarily good. In addition, the opening angle may be insufficient. Although it is possible to improve this point by increasing the initial tension of the coil sheath, the sheath does not move in the body along the curvature of the body lumen or at the entrance and exit of the instrument guide tube of the endoscope. It needs to be curved, and if the initial tension is increased, it becomes difficult to curve, so it cannot be excessively increased.

JP 2010-42052 A

The present invention has been made in view of these points, and is a forceps-type forceps device that can improve the responsiveness when opening a pair of forceps pieces and the insufficient opening angle while realizing the necessary curvature in the body. An object is to provide a treatment tool.

A forceps-type treatment instrument according to the present invention includes:
a support member provided at the distal end of a sheath through which the drive wire is inserted; and a pair of forceps pieces rotatably attached to the support member and opened and closed by sliding the drive wire with respect to the sheath. A forceps-type treatment instrument having
The sheath has a coil sheath made of a tightly wound coil spring,
The forceps-type procedure in which the initial tension of the coil sheath on the proximal end side to be placed outside the body is set to a larger value than the initial tension on the distal end side of the coil sheath inserted into the body. It is a tool.

In the forceps-type treatment instrument according to the present invention, the initial tension of the coil sheath on the distal end side of the coil sheath that is inserted into the body is greater than the initial tension of the rest of the proximal end side that is placed outside the body. set to a value. For this reason, a portion of the distal end side to be inserted into the body has a relatively low initial tension so as to ensure the necessary curvature, and the remaining portion of the proximal end side to be placed outside the body has a relatively low initial tension. By applying a relatively high initial tension, it is possible to improve the responsiveness and insufficient opening angle when opening the pair of forceps pieces while achieving the necessary bendability in the body.

INDUSTRIAL APPLICABILITY The present invention can be applied to a forceps-type high-frequency treatment instrument in which each forceps piece of a pair of forceps pieces is an electrode through which a high-frequency current flows. In a forceps-type high-frequency treatment instrument, it is possible to improve the responsiveness when opening a pair of forceps pieces and the insufficient opening angle while realizing the necessary bendability in the body.

The forceps-type treatment instrument according to the present invention may further include an outer sheath through which the coil sheath is used as an inner sheath and the inner sheath is rotatably inserted. By rotating the inner sheath with respect to the outer sheath, the pair of forceps pieces can be rotated around the central axis of the sheath.

1A is a plan view showing the overall configuration of a forceps-type treatment instrument according to an embodiment of the present invention; FIG. FIG. 1B is a cross-sectional view taken along line Ib--Ib of FIG. 1A. FIG. 2A is a cross-sectional view showing the configuration of the distal end side of the forceps-type treatment instrument in FIG. 1A, showing a state in which the forceps pieces are closed. FIG. 2B is a plan view of FIG. 2A. FIG. 2C is a cross-sectional view showing the open state of the forceps piece of FIG. 2A. FIG. 2D is a plan view of FIG. 2C. 3A is an enlarged perspective view of the forceps piece of FIG. 2A. FIG. FIG. 3B is a plan view of FIG. 3A. 4A is an enlarged perspective view of the insulating spacer of FIG. 2A. FIG. FIG. 4B is a side view of FIG. 4A.

A bipolar hemostatic forceps, which is one of forceps-type high-frequency treatment instruments, will be specifically described below as an embodiment of the present invention with reference to the drawings. However, the present invention is not limited to forceps-type high-frequency treatment instruments, and can be applied to forceps-type treatment instruments having forceps pieces that do not function as electrodes.

First, refer to FIGS. 1A and 1B. The bipolar hemostatic forceps of this embodiment is a forceps-type high-frequency surgical instrument used for cauterizing and coagulating tissues in the body to stop bleeding, and generally includes a sheath section 1, an operating section 2, and a treatment section 3. . An operating portion 2 is provided on the proximal end side of the sheath portion 1, which is arranged outside the body, and a treatment portion 3 is provided on the distal end side of the sheath portion 1, which is inserted into the body through an endoscope.

The operating portion 2 includes a base 21, a slider 22, and a distal end cap 23, and the treatment portion 3 includes a forceps portion having a pair of forceps pieces (electrodes) 31 that can be opened and closed with each other. As a result, the pair of forceps pieces 31 can be opened and closed and rotated around the central axis.

The operation unit 2 includes a pair of electric wires (cables) 24a and 24b and a plug 24 provided on the proximal end side of these electric wires 24a and 24b. It is electrically connected to the device and is adapted to be supplied with high-frequency current. The electric wire 24a is electrically connected to one forceps piece 31 via a drive wire 13a described later, and the electric wire 24b is electrically connected to the other forceps piece 31 via a drive wire 13b described later.

The sheath portion 1 includes a tubular outer sheath 11, a tubular inner sheath 12, and a pair of drive wires 13a and 13b. The total length L of the sheath portion 1 is set within a range of about 1600 to 2000 mm, depending on the site of the target biological tissue to be cauterized.

The outer sheath 11 is composed of a flexible hollow tube, and a tube made of an insulating resin is used. The resin material forming the outer sheath 11 is not particularly limited as long as it is an electrically insulating material, and polyethylene, polypropylene, polyvinyl chloride, polyurethane, polyamide, polyester, polycarbonate, polyethersulfone, fluororesin, etc. can be used. .

The inner sheath 12 is made of a flexible elongated cylindrical body, is inserted through the outer sheath 11 as shown in FIG. The inner sheath 12 is a coil sheath using a coil tube made of a closely wound coil spring.

As the coil tube forming the inner sheath 12, in this embodiment, a round wire coil tube formed by tightly winding a round wire (a wire rod having a circular cross section) made of metal such as stainless steel in a helical shape is used. However, a flat wire coil tube using wires having a rectangular cross section or a coil tube using wires having other cross-sectional shapes may be used. The inner sheath 12 is also a power transmission member for transmitting a turning force for turning the pair of forceps pieces 31 around the sheath axis for posture adjustment.

In this embodiment, as the coil tube that constitutes the inner sheath 12, a single strand wound tightly in a helical shape is used. It may be arranged in parallel and tightly wound spirally.

In the coil sheath that constitutes the inner sheath 12, the initial tension of the rest of the portion on the proximal end side is set to a larger value than the initial tension of the portion on the distal end side. That is, the initial tension of a part on the distal end side is set to a relatively small value, and the initial tension of the remaining part on the proximal end side is set to a relatively large value.

The initial tension of a portion of the distal end side of the coil sheath that constitutes the inner sheath 12 is set to a value that allows the coil sheath to smoothly follow the curvature of the body lumen, the entrance and exit of the instrument guide tube of the endoscope, and the like. can be set, for example, in the range of 1.9 to 2.5N. The initial tension of the remainder of the proximal end side of the coil sheath that constitutes the inner sheath 12 is the initial tension of the inner sheath 12 when the drive wires 13a and 13b are pushed out against the inner sheath 12 in order to open the pair of forceps pieces 31. It is set from the viewpoint of minimizing expansion, and can be set, for example, in the range of 13 to 17N. The length of the portion where the initial tension on the distal end side of the coil sheath that constitutes the inner sheath 12 is set relatively small is set according to the length of the portion of the sheath 1 that is planned to be inserted into the body. can be set, for example, in the range of 55 to 67%.

As a method of reducing the initial tension of the coil sheath on the distal end side and increasing it on the proximal end side, various parameters (temperature, tension, etc.) It may be done by making it different from the end side, but the position of the coiling pin and other tools used when winding the wire around the core bar is adjusted to increase the initial tension on the proximal end side (winding ), it is preferable to manufacture so that the initial tension on the distal end side becomes smaller.

As shown in FIG. 1B, the pair of drive wires 13a and 13b are inserted through the inner sheath 12, and the drive wires 13a and 13b can slide within the inner sheath 12 (slid in the axial direction). It's becoming The drive wires 13a and 13b are wires having flexibility and conductivity, and are insulated from each other by providing an insulating coating on their surfaces. The drive wires 13a and 13b are power transmission members for transmitting a sliding force for opening and closing the pair of forceps pieces 31, and also members constituting an electric circuit for supplying high-frequency power to the pair of forceps pieces 31. (Electric wire).

In the operation portion 2, the base 21 has a finger ring portion 21a and a guide portion 21b having a guide groove. The slider 22 is attached so as to be slidable back and forth (up and down in FIG. 1A) along the guide portion 21b of the base 21 . A tip cap 23 is in contact with the tip (distal end) of the base 21 . Base 21, slider 22 and tip cap 23 are mainly made of insulating resin.

The proximal end of the outer sheath 11 is fixed to the tip cap 23, and the inner sheath 12 through which the drive wire 13 is inserted is arranged to pass through a through hole formed inside. The tip cap 23 is separated from the tip of the base 21 and is rotatable with respect to the base 21 . The proximal end of the inner sheath 12 is fixed to the distal end of the base 22, and the proximal ends of the pair of drive wires 13a, 13b are fixed to the slider 22, respectively.

By sliding the slider 22 back and forth (up and down in FIG. 1A) with respect to the base 21, the drive wires 13a and 13b can be slid in the inner sheath 12 in its axial direction. By rotating the base 21 and the slider 22 with respect to the tip cap 23, the inner sheath 12 and the drive wire 13 can be rotated with respect to the outer sheath 11 around their axes.

The treatment section 3 is forceps-like for grasping body tissue to stop bleeding, and as shown in FIGS. , a resin frame (supporting member) 32, an insulating spacer 33, and the like.

The resin frame 32 has a substantially cylindrical base end portion 32b having a flange portion, and a pair of arm portions 32a projecting from the base end portion 32b in the Z-axis direction and facing each other in the X-axis direction. In the drawings, the X, Y and Z axes are perpendicular to each other.

Fitting holes 32c penetrating inside and outside (in the X-axis direction) are formed in the vicinity of the tip portions of the pair of arm portions 32a (see FIGS. 2B and 2D). A proximal end portion 32b of the resin frame 32 is fixed to the distal end of the inner sheath 12 via a substantially cylindrical fixing member 34 made of resin or the like. Specifically, the proximal end portion 32b of the resin frame 32 is inserted from the distal end side of the lumen of the fixing member 34, and the distal end portion of the inner sheath 12 is inserted from the proximal end side of the lumen of the fixing member 34. , which are adhesively fixed to each other with an adhesive.

The drive wires 13a, 13b are arranged to pass through the lumen of the base end portion 32b of the resin frame 32, and the distal end of one drive wire 13a is connected to the through hole 31c1 of one forceps piece 31. The distal end of the other drive wire 13b is connected to the through hole 31c1 of the other forceps piece 31. As shown in FIG.

The distal end of the drive wire 13a is stripped of its insulating coating and is electrically connected to one forceps piece 31, and similarly the distal end of the drive wire 13b is stripped of its insulating coating and connected to the other forceps piece. 31 are electrically connected. Therefore, one forceps piece 31 is electrically connected to the wire 24a (see FIG. 1A) through the drive wire 13a, and the other forceps piece 31 is electrically connected to the wire 24b (see FIG. 1A) through the drive wire 13b. ) is electrically connected to

The shape of each fitting hole 32c of the pair of arm portions 32a is substantially circular so that the tip end portion of the shaft portion 33a of the insulating spacer 33, which will be described later, can be fitted.

The pair of forceps pieces 31 are rotated so as to cross each other (to form a substantially X shape) while being electrically insulated from each other by an insulating spacer 33 made of insulating resin (for example, polycarbonate). It is supported as possible, and in this state is arranged between the pair of arm portions 32 a of the resin frame 32 .

In this embodiment, the pair of forceps pieces 31 have substantially the same shape. As shown in FIGS. 3A and 3B, the forceps piece 31 is a member integrally having a grip portion 31a, a shaft support portion 31b and a connection portion 31c, and is made of a conductive metal material such as stainless steel. ing.

The shaft support portion 31b is a portion provided with a shaft hole 31b1 that forms a central axis of rotation of the resin frame 32 with respect to the arm portion 32a. The connection portion 31c is provided closer to the proximal side than the pivot portion 31b, and is a portion to which the distal end portion of the drive wire 13a or 13b is mechanically and electrically connected. is formed with a through hole 31c1. The distal end portions of the driving wires 13a and 13b are appropriately bent or the like and passed through the corresponding through holes 31c1 of the forceps pieces 31, thereby being locked to the connection portion 31c.

The grasping portion 31a is provided on the distal end side of the pivotal support portion 31b, and is a portion for grasping a living tissue as a grasping target portion. The grip portion 31a has a flat flat portion 31a1 and a pair of tip convex teeth 31a2 provided at the tip of the flat portion 31a1. Each tip convex tooth 31a2 is erected so as to face the inside (one side of the opposing forceps). The flat portion 31a1 is a flat surface on which no ridge teeth or other projections are provided except for the pair of tip convex teeth 31a2.

When the pair of forceps pieces 31 are closed (see FIGS. 2A and 2B), the flat portion 31a1 of one forceps piece 31 and the flat portion 31a1 of the other forceps piece 31 They are configured to be substantially parallel to each other and face each other with a predetermined gap therebetween. In this case, the interval between the plane portion 31a1 of one forceps piece 31 and the plane portion 31a1 of the other forceps piece 31 is set according to the site of the living tissue to be cauterized, and is, for example, 0.3 to 0.6 mm. Set in range.

When the pair of forceps pieces 31 are closed (see FIGS. 2A and 2B ), the pair of tip convex teeth 31 a 2 of the gripping portion 31 a are arranged so that the tip surface of the tip convex teeth 31 a 2 of one forceps piece 31 and the tip surface of the other forceps piece 31 are aligned. and the tip surface of the tip convex tooth 31a2 are configured to abut or approach each other.

Further, the flat portion 31a1 of the grip portion 31a is provided on the base end portion side (the shaft support portion 31b side) and has a wide portion 31a3 having a pair of sides set substantially parallel to each other, It has a pair of side edges set substantially parallel to each other, and has a narrow width portion 31a4 set to a width narrower than the width (width in the X-axis direction) of the wide width portion 31a3. For this reason, cut portions 31a5 are formed on both sides of the grip portion 31a on the tip side. The tip convex tooth 31a2 is provided at the tip of the narrow width portion 31a4.

A shaft hole 31b1 formed in the shaft support portion 31b of the forceps piece 31 has a substantially circular cross section, and a notch portion 31b2 extending radially outward from the axis is formed in a part of the inner peripheral surface of the shaft hole 31b1. It is A protrusion 33f formed on the shaft portion 33a of the insulating spacer 33 is loosely fitted in the cutout portion 31b2 (see FIGS. 2A, 2C, 4A, and 4B), and when the forceps piece 31 is rotated, The rotation angle of the forceps piece 31 is defined by the protrusion 33f coming into contact with the inner surface on one side or the inner surface on the other side of the notch 31b2 in the circumferential direction.

The insulating spacer 33 is a member that rotatably supports the pair of forceps pieces 31 in a state of being electrically insulated from each other. It roughly has a portion 33c and a pair of substantially cylindrical shaft portions 33a projecting from both sides of the spacer portion 33c. The pair of shaft portions 33a are symmetrical with each other and arranged coaxially. The through holes 33d in the central portions of the pair of shaft portions 33a are communicated with each other through the spacer portion 33c.

The shaft portion 33 a has an outer diameter slightly smaller than the inner diameter of the shaft hole 31 b 1 of the forceps piece 31 so that it can be rotatably inserted into the shaft hole 31 b 1 of the forceps piece 31 . The axial dimension (height) of the shaft portion 33 a is set so that the tip portion of the shaft portion 33 a fits into the fitting hole 32 c of the arm portion 32 a of the resin frame 32 .

Further, the shaft portion 33a has a projection portion 33f that protrudes radially outward in a cross section perpendicular to the axis of the shaft portion 33a. The projecting portion 33f is formed so as to be movably disposed within a notch portion 31b2 formed in the shaft hole 31b1 of the forceps piece 31 when the shaft portion 33a is inserted into the shaft hole 31b1.

The spacer portion 33c is integrally provided with a support projection 33g projecting from one surface and a support projection 33g projecting from the other surface. These support projections 33g are for defining the interval between the pair of arm portions 32a of the resin frame 32, and do not hinder the rotation of the corresponding forceps piece 31 at a part of the edge portion of the spacer portion 33c. placed in position.

In the above-described embodiment, the coil sheath that constitutes the inner sheath 12 has an initial tension greater than the initial tension of the portion of the distal end that is inserted into the body, the initial tension of the remainder of the proximal end that is placed outside the body. is set to a large value. For this reason, a portion of the distal end side to be inserted into the body has a relatively low initial tension so as to ensure the necessary curvature, and the remaining portion of the proximal end side to be placed outside the body has a relatively low initial tension. By applying a relatively high initial tension, it is possible to improve the responsiveness and insufficient opening angle when opening the pair of forceps pieces 31 while realizing the necessary curvature in the body.

It should be noted that the embodiments described above are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above-described embodiment is meant to include all design changes and equivalents that fall within the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1... Sheath part 11... Outer sheath 12... Inner sheath (coil sheath)
DESCRIPTION OF SYMBOLS 13a, 13b... Drive wire 2... Operation part 21... Base 22... Slider 23... Tip cap 24... Plug 24a, 24b... Electric wire 3... Treatment part 31... Forceps piece 31a... Grip part 31a1... Flat part 31a2... Tip convex tooth 31a3 Wide portion 31a4 Narrow portion 31a5 Notch 31b Shaft 31b1 Shaft hole 31b2 Notch 31c Connecting portion 31c1 Through hole 32 Resin frame (supporting member)
32a arm portion 32b base end portion 32c fitting hole 33 insulating spacer 33a shaft portion 33c spacer portion 33d through hole 33f protrusion 33g support protrusion

Claims (3)

a support member provided at the distal end of a sheath through which the drive wire is inserted; and a pair of forceps pieces rotatably attached to the support member and opened and closed by sliding the drive wire with respect to the sheath. and a forceps-type treatment instrument in which the distal end side of the sheath is inserted into the body via an endoscope ,
The total length of the sheath is in the range of 1600 to 2000 mm,
The sheath has a coil sheath made of a tightly wound coil spring,
The initial tension of the remaining portion of the coil sheath on the proximal end side to be placed outside the body is set to a larger value than the initial tension of the portion on the distal end side to be inserted into the body ,
The initial tension of a part of the distal end side of the coil sheath is set in the range of 1.9 to 2.5 N,
The initial tension of the remainder of the coil sheath on the proximal end side is set in the range of 13 to 17 N,
A forceps-type treatment instrument , wherein the length of a portion of the coil sheath on the distal end side is set within a range of 55 to 67% of the total length of the sheath. 2. A forceps-type treatment instrument according to claim 1, wherein each forceps piece of said pair of forceps pieces is an electrode through which a high-frequency current is applied. 3. The forceps-type treatment instrument according to claim 1, further comprising an outer sheath through which said coil sheath is used as an inner sheath and said inner sheath is rotatably inserted.

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