JP4223606B2 - Endoscopic biopsy forceps - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an endoscopic biopsy forceps that is inserted into a forceps channel of an endoscope and used to collect a biopsy tissue specimen from within a body cavity.
[0002]
[Prior art]
FIG. 9 shows a distal end portion of a general endoscopic biopsy forceps, and an operation wire 2 inserted through a flexible sheath 1 to be inserted into and removed from the forceps channel of the endoscope is axially disposed. The pair of forceps cups 11 disposed at the distal end of the sheath 1 is opened and closed in a hook shape around the support shaft 12 by moving forward and backward.
[0003]
When the biopsy tissue is collected, the operation wire 2 is pulled toward the proximal side to close the pair of forceps cups 11, so that the tissue is cut and closed by the edge of each forceps cup 11 formed in a blade shape. A biopsy tissue specimen is collected in the pair of forceps cups 11.
[0004]
[Problems to be solved by the invention]
Each of the pair of forceps cups 11 is provided with a shaft hole 13 into which the support shaft 12 is rotatably fitted. Therefore, as shown in FIG. 10, if the shaft hole 13 is accurately formed on the extension line of the meshing surface A of the forceps cup 11, the pair of forceps cups 11 is as shown in FIG. 9. Engages perfectly and can cut the biopsy tissue reliably.
[0005]
However, in reality, it is unavoidable that machining errors occur, and as shown in FIG. 11, the shaft hole 13 is shifted outward from the original position, and the forceps cup 11 is bitten as shown in FIG. 12. As shown in FIG. 13, the shaft hole 13 is displaced inward from the original position as shown in FIG. 13, and the engagement of the forceps cup 11 is opened in the abdomen as shown in FIG. There are many cases where cutting of the tissue is uncertain. Note that FIGS. 12 and 14 show the state of deviation slightly exaggerated.
[0006]
Therefore, the present invention provides an endoscopic biopsy forceps that can reliably cut a biopsy tissue by correctly engaging a pair of forceps cups even if there is a machining error in the position of the shaft hole. For the purpose.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the biopsy forceps for an endoscope of the present invention performs an advance / retreat operation in an axial direction on an operation wire that is inserted through a sheath inserted into and removed from the forceps channel of the endoscope. In the endoscopic biopsy forceps in which a pair of forceps cups arranged at the distal ends of the sheaths are opened and closed in a hook shape around a support shaft, the support shafts are passed through the pair of forceps cups. A shaft hole of at least one forceps cup is widened in a direction substantially orthogonal to the meshing surfaces of the pair of forceps cups so as to be displaceable with respect to the support shaft. It is characterized by.
[0008]
The shaft hole may be an elongated hole that is elongated in a direction substantially orthogonal to the meshing surfaces of the pair of forceps cups. In this case, the shaft hole is formed on the meshing surfaces of the pair of forceps cups. A long hole extending on both sides of the extension line, or a long hole in which the shaft hole is extended to one side of the extension line of the engagement surface of the pair of forceps cups may be used.
[0009]
In addition, the shaft hole may be a circular hole in a fitting state that can be displaced with respect to the support shaft. In this case, only one shaft hole of the pair of forceps cups with respect to the support shaft. It is possible to match the distance from the tip of each forceps cup to the shortest edge of the shaft hole.
[0010]
In addition, only one shaft hole of the pair of forceps cups is a circular hole that can be displaced with respect to the support shaft, and the distance from the tip of each forceps cup to the center position of the shaft hole You may match.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
FIG. 2 shows an endoscopic biopsy forceps. A flexible sheath 1 inserted into and removed from a forceps channel of an endoscope (not shown) is composed of, for example, a tightly wound coil pipe, The operation wire is inserted and arranged over the entire length so as to freely advance and retract in the axial direction. The sheath 1 may have a tightly wound coil pipe covered with a flexible tube or other configurations.
[0012]
An operation unit 20 for moving the operation wire forward and backward is connected to the proximal end (hand side) of the sheath 1, and a distal end working unit 10 driven by the operation wire is connected to the distal end of the sheath 1. Yes.
[0013]
FIG. 1 shows a distal end working unit 10, and a distal end body 4 in which a large slit 3 is formed from the front side is connected and fixed to the distal end of the sheath 1, so that the vicinity of the distal end of the slit 3 is crossed. A support shaft 12 is attached to the tip body 4.
[0014]
The pair of forceps cups 11 are pivotally supported by the respective support shafts 12 so as to open and close in a bowl shape around the support shaft 12, and are driven by the operation wire 2 to open and close the forceps cup 11. A known link mechanism 15 is disposed in the slit.
[0015]
The link mechanism 15 is formed in a so-called pantograph shape in which the four links 151 to 154 are connected to each other in an annular manner so that the two links 151 and 152 on the front side thereof are connected to the pair of forceps cups 11. It is integrally formed continuously and rotates around the support shaft 12.
[0016]
The two intermediate links 153 and 154 that are rotatably connected by the two links 151 and 152 and the connecting shafts 155 and 156 are rotatably connected to the drive rod 158 on the rear end side by the connecting shaft 157. Yes.
[0017]
The tip of the operation wire 2 is connected and fixed to the drive rod 158, and the link mechanism 10 is operated by remote operation from the hand side (right side in FIG. 1), and a pair of the operation wire 2 is pushed forward. When the forceps cup 11 is opened as indicated by a two-dot chain line and the operation wire 2 is pulled toward the hand side, the forceps cup 11 is closed as indicated by a solid line.
[0018]
FIG. 3 shows one of the pair of forceps cups 11 of the endoscopic biopsy forceps configured as described above. As a shaft hole 13 through which the support shaft 12 passes, the forceps cup is engaged. An elongated long hole is formed in a direction substantially orthogonal to the surface A. The shaft hole 13 of the other forceps cup 11 (not shown) is formed with a thickness that allows the support shaft 12 to be inserted without rattling.
[0019]
The width W of the shaft hole 13 is a dimension through which the support shaft 12 passes with little backlash, and the length L is extended on both sides of the extension line of the engagement surface A of the forceps cup 11 so as to support the support shaft. 12 is formed to be displaceable. Specifically, it is formed, for example, about 0.3 to 0.5 mm longer than the diameter of the support shaft 12.
[0020]
As a result, even when the shaft hole 13 of the other forceps cup 11 is misaligned, the shaft hole 13 formed in the shape of a long hole is displaced with respect to the support shaft 12, and as shown in FIG. The forceps cup 11 is always in a close state.
[0021]
If the displacement of the shaft hole 13 of the other forceps cup 11 causes a gap to be opened at the tip of the forceps cup 11 as shown in FIG. 12, the forceps cup 11 as shown in FIG. It may be a long hole-shaped shaft hole 13 extending only inward from an extension line of the meshing surface A.
[0022]
In addition, when the displacement of the shaft hole 13 of the other forceps cup 11 causes a gap in the abdomen of the forceps cup 11 as shown in FIG. 14, the forceps cup 11 has a gap as shown in FIG. It may be a long hole-shaped shaft hole 13 extending only outward from the extension line of the meshing surface A. Further, both the shaft holes 13 of the pair of forceps cups 11 may be long holes.
[0023]
FIG. 6 shows the distal end working part 10 of the biopsy forceps for endoscope according to the second embodiment of the present invention, and the shape of the shaft hole 13 of one forceps cup 11 is defined with respect to the support shaft 12. It is a circular hole that is in a displaceable fitting state, and the shaft hole 13 of the other forceps cup 11 is formed to a thickness that allows the support shaft 12 to be inserted without play. Others are the same as those in the first embodiment.
[0024]
The diameter of the shaft hole 13 is, for example, about 0.3 to 0.5 mm larger than the diameter of the support shaft 12, and even if configured in this way, the pair of forceps cups 11 are engaged with each other as in the first embodiment. The surfaces A can be closed without gaps.
[0025]
In such a structure, in order to prevent the pair of forceps cups 11 from shifting in the front-rear direction when they are engaged, as shown in FIG. 7, the shaft positioned at the shortest distance from the tip of each forceps cup 11. The distance Y to the edge of the hole 13 may be matched between the pair of forceps cups 11.
[0026]
However, as shown in FIG. 8, if the distances from the tips of the forceps cups 11 to the center position of the shaft hole 13 are matched, the tips of the forceps cups 11 are slightly shifted in the front-rear direction at the time of meshing. In some cases, the shear force acts on the biopsy tissue sandwiched between the two, so that it is cut well.
[0027]
【The invention's effect】
According to the present invention, the pair of forceps cups can be displaced with respect to the support shaft by expanding the shaft hole of at least one forceps cup in a direction substantially orthogonal to the meshing surfaces of the pair of forceps cups. When the shaft is closed, the shaft hole is displaced with respect to the support shaft, and even if there is a machining error in the position of the shaft hole, the pair of forceps cups are correctly meshed, and the biopsy tissue can be cut reliably.
[Brief description of the drawings]
FIG. 1 is a side view showing a partial cross section of a distal end portion of an endoscopic biopsy forceps according to a first embodiment of the present invention.
FIG. 2 is a side view of the endoscopic biopsy forceps according to the first embodiment of the present invention.
FIG. 3 is a side view of one forceps cup according to the first embodiment of the present invention.
FIG. 4 is a side view of a modified example of one forceps cup according to the first embodiment of the present invention.
FIG. 5 is a side view of a second modification of one forceps cup according to the first embodiment of the present invention.
FIG. 6 is a side view showing a partial cross section of a distal end portion of an endoscopic biopsy forceps according to a second embodiment of the present invention.
FIG. 7 is a side view of one forceps cup according to the second embodiment of the present invention.
FIG. 8 is a side view of a modified example of one forceps cup according to the second embodiment of the present invention.
FIG. 9 is a side view showing a partial cross section of a distal end portion of a conventional endoscopic biopsy forceps.
FIG. 10 is a side view of one conventional forceps cup.
FIG. 11 is a side view of one conventional forceps cup.
FIG. 12 is a side view showing a partial cross section of a distal end portion of a conventional endoscopic biopsy forceps.
FIG. 13 is a side view of one conventional forceps cup.
FIG. 14 is a side view showing a partial cross section of a distal end portion of a conventional endoscopic biopsy forceps.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sheath 2 Operation wire 11 Forceps cup 12 Support shaft 13 Shaft hole A Meshing surface

Claims (7)

A pair of forceps cups arranged at the distal end of the sheath can be pivoted to the support shaft by operating the operation wire inserted and removed in the sheath inserted into and removed from the forceps channel of the endoscope in the axial direction. In an endoscopic biopsy forceps that is pivotally supported by an axis and is driven to open and close like a saddle around the above-mentioned pivot.
To the pair of forcep cups are shaft hole is drilled to the support shaft serving as a rotation supporting point is passed, the axial hole of at least one of the forceps cups, with respect to mating surfaces of the pair of forcep cups An endoscopic biopsy forceps that is widened in a direction substantially orthogonal to the diameter of the support shaft and is displaceable with respect to the support shaft. The endoscopic biopsy forceps according to claim 1, wherein the shaft hole is a long and narrow hole extending in a direction substantially orthogonal to the meshing surfaces of the pair of forceps cups. The biopsy forceps for an endoscope according to claim 2, wherein the shaft hole is a long hole extending on both sides of an extension line of a meshing surface of the pair of forceps cups. The biopsy forceps for an endoscope according to claim 2, wherein the shaft hole is a long hole extending to one side of an extension line of the meshing surfaces of the pair of forceps cups. The biopsy forceps for an endoscope according to claim 1, wherein the shaft hole is a circular hole in a fitting state that is displaceable with respect to the support shaft. Of the pair of forceps cups, only one shaft hole is a circular hole that can be displaced with respect to the support shaft, and the distance from the tip of each forceps cup to the shortest edge of the shaft hole matches. The biopsy forceps for an endoscope according to claim 5, wherein the forceps are used. Of the pair of forceps cups, only one shaft hole is a circular hole that can be displaced with respect to the support shaft, and the distance from the tip of each forceps cup to the center position of the shaft hole is matched. The endoscopic biopsy forceps according to claim 5.

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