JPH06315462A - Scissors forceps for endoscope - Google Patents

Abstract

PURPOSE:To provide blades with a high cutting ability through its full length regardless of its length by giving blades bent shape at the crossing side and by giving a holder a method that makes the blades contact each other from an opening point to a closing point. CONSTITUTION:Blades 18 and 20 are continuously bent from the point P from where edges 19 and 21 begin to be contacted to make a reaction force so that the edges 19 and 21 are closely contacted. As a result, a bent shape is made from the longitudinally center of the blades 18 and 20 to heads 18b and 20b. As the contact point P moves towards the head, the displacements of the blades 18 and 20 become larger, however, the distance from the point P to the fixed portion between legs 30a and 30b of a holder 30, that is the distance from the point P to operation points 18a and 20a connected between the legs 30a and 30b of the holder 30 using a fulcrum pin 32, is larger, and the spring constant of a plate spring becomes smaller. Therefore, the reaction force generated is almost constant regardless of the contact point P.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to endoscopic scissor forceps for use in endoscopic surgery, particularly for cutting.

[0002]

2. Description of the Related Art An example of scissors forceps for an endoscope used in a surgical operation under the endoscope is described in Japanese Patent Laid-Open No. 4-246344. This conventional scissor forceps pivotally attaches a pair of blades to the tip of a long outer tube, and pushes and pulls a rod that has passed through the outer tube to open and close the blades to cut a site to be cut such as an organ or a blood vessel. Form scissors to cut. The pair of blades of the scissors forceps are curved laterally, that is, in the same direction in the thickness direction, over their entire length, and when they are closed, the entire side portions facing each other are in contact with each other without a gap. Further, a spring washer is arranged at the pivotal portion that forms the fulcrum of the scissors, and a short blade length that elastically biases the movable side blade and the fixed side blade that extend linearly in the opposite side direction is also described. ing.

[0003]

However, in the scissors forceps in which the pair of blades are curved in the same direction in the thickness direction as described above, the pressing force in the opposing direction does not act between the blades. Therefore, little force is generated to bring the blade portions of the blades into contact with each other. For this reason,
When cutting, the blades are separated from each other, and the function as scissors cannot be fully exerted.

When a spring washer is provided at the blade pivot portion, the elastic force of the springs urges the blades toward each other. However, the elastic urging force causes the blades to approach the tip of the blade. However, effective shearing cannot be performed particularly near the tip of the blade. This spring washer needs to be housed in a very small gap between the scissors member at the tip of the outer tube,
Therefore, the spring stroke cannot be increased,
It is difficult to apply to scissors forceps with long blade length.

The present invention has been made in view of the above circumstances, and an object thereof is to provide scissors forceps for an endoscope which can effectively cut the entire length of the blade even if the blade length is long. To do.

[0006]

The scissors forceps of the present invention is a scissors forceps for an endoscope which has a pair of openable and closable blades whose base ends are pivotally attached to each other and which are held by a holding member. Has a curved shape laterally intersecting the respective blade portions, the holding member, characterized in that it has a biasing means for contacting the blade portions of each blade from the open position to the closed position. is there.

[0007]

With this scissors forceps for an endoscope, each blade having a sidewardly curved shape is brought into contact with its blade portion by the urging means, so that one blade portion has its tip portion at the other end. If a pair of blades is closed when cutting the site to be cut so as to intersect with the blade portion so as to project laterally, the intersecting point moves from the base end side to the tip end side. Due to this curved structure of the blade, when the blade is closed, a force is generated that attempts to separate the base end side from the point where the blade portions intersect, this force is absorbed by the biasing means, and the blade of each blade is always The state where the parts are in contact is maintained.

[0008]

1 to 4 show an endoscope scissors forceps 10 according to a first embodiment of the present invention. This endoscopic scissors forceps 10
As shown in FIG. 1, is formed of a tip portion 12, an insertion portion 14, and an operation portion 16.

The tip portion 12 has a pair of blades 18, 2
0 and its opening / closing (driving) mechanism 22 are arranged. The opening / closing mechanism 22 includes a tubular sheath 2 that forms the insertion portion 14.
4 is connected to the tip end side of the operation rod 25 arranged in the unit 4. The proximal end side of the operating rod 25 is provided with one of the pair of handles 26, 27 of the insertion portion 16.
To the connecting member 28.

Such scissors forceps 10 is inserted into the abdominal cavity of a patient via a trocar (not shown). Handle 26,
When the operator opens and closes 27 from outside the body, the blades 18 and 20 of the tip portion 12 are opened and closed, and the blade portions 19 and 21 can cut a desired cut site such as an organ, a blood vessel, or a peritoneum.

In the case of the grasping forceps or the peeling forceps, the target portion can be grasped or peeled by opening / closing the tip portion similarly by opening / closing the handle.

2 and 3, the tip portion 12 of the scissors forceps 10 is shown.
As shown in enlarged form, the opening / closing mechanism 22 for opening / closing the pair of blades 18 and 20 has a hollow structure holding member 30 fixed to the distal end of the sheath 24. A slot 31 is formed on the tip side of the holding member 30, and the base ends of the blades 18 and 20 are housed in the slot 31.
The blades 18 and 20 and the holding member 30 are rotatably attached by a fulcrum pin 32. The leg portions 30a and 30b of the holding member 30 forming the slot 31 elastically hold the base end portions of the blades 18 and 21 from both sides, and, as described later, the blade portions 1 of the blades 18 and 20.
An urging means for making the 9 and 21 cross each other and contacting each other is configured. The symbol P in the drawing indicates the point where the blade portions 19 and 21 of the blades 18 and 20 contact or intersect.

Blade 1 arranged in slot 31
The base end portions of the blades 8 and 20 have operating portions 18a and 20a extending from the blade portions 19 and 21 to the opposite side to open and close the blade portions 19 and 21 with the fulcrum pin 32 as a stop. These operating portions 18a and 20a are formed in a straight or flat plate shape in order to make the operation of the opening / closing mechanism 22 accurate, and the thickness thereof is also uniform. The end portions of these operating portions 18a and 20a are respectively connected to the connecting pin 3
The links 38, 40 are connected to one end sides of the links 38, 40 via 4, 36. The other ends of these links 38 and 40 are both pivotally attached to the tip of the drive member 42 by a pin 44.

The drive member 42 is inserted through the holding member 30 so as to be movable in the axial direction, and the base end portion of the drive member 42 is connected to the tip end portion of the operating rod 25. The tip 43 of the drive member 42 has a flat shape, and a pin hole is formed in the tip 43. Pin 4 in this pin hole
4 and insert the above-mentioned link 3 on both ends of this pin 44.
The other end side of 8, 40 is rotatably connected.

As shown in FIG. 2B and FIG. 3B, the blades 18, 20 are curved especially in the direction in which their blade portions 19, 20 are lateral, that is, in the direction opposite to each other. When the blades 18 and 20 are opened, the blade portions 19 and 21 of the blades 18 and 20 are arranged so as to intersect each other at point P. These blades 18, 20 are formed of a suitable material having the required toughness and elasticity, such as steel.

The portion of the blade 18 on the tip side of the operating portion 18a, that is, the portion where the blade portion 19 is provided, is a fulcrum pin 32.
Begins to bend from the tip side of the near part. And the tip 18
As it reaches b, it draws an arc toward the opposite blade 20. Further, a blade 20 that makes a pair with the blade 18
Also, basically, the blade 18 has the same shape as the blade 18, and the portion where the blade portion 21 is formed is curved in the opposite direction to the portion where the blade portion 19 of the blade 18 is formed.

On the other hand, as shown in FIG. 4, the holding member 30 for holding such blades 18 and 20 has a leg portion 3 thereof.
Pin engagement holes 29, 29 are formed in 0a, 30b. Countersunk spots 29a, 29a are formed at the respective open ends of these pin engaging holes 29, 29. And
Both ends 32a, 32a of the fulcrum pin 32 are caulked and fixed so as to come into close contact with these countersunk spots 29a, 29a.

Next, the operation of the scissors forceps 10 for an endoscope of this embodiment will be described. As shown in FIG. 2, the blade 18,
When the driving member 42 is moved to the right in the drawing through the handles 26 and 27, the connecting member 28, and the operating rod 25 (FIG. 1) from the opened state of the link 20, the link 1 connected by the pin 44
The ends of 7, 18 are pulled to the right and the blades 18, 20
Closes to the state shown in FIG. The tip portions 18b and 20b of the blades 18 and 20 further move after the tip portions of the blade portions 19 and 20 contact each other, and one tip of the blade portions 19 and 21 moves beyond the other tip by a predetermined amount. State, each tip 1
The opposite side portions of 8a and 20a are overlapped and stopped. At this time,
As shown in FIG. 3 (B), the portions between the distal end portions 18b and 20b and the proximal end portions 18a and 20a are separated from each other due to the curved shapes of both portions.

In order to perform a cutting operation using the scissors forceps 10, a shearing force that overcomes the hardness or toughness of the cut portion or the cut object is applied to the blade portions 19, 20 of the blades 18, 20.
21 need to be generated. Scissors forceps 10 of this embodiment
Forms each of the blades 18 and 20 into a curved shape and then displaces the blades 18 and 20 in directions opposite to each other to bring the blade portions 19 and 21 into contact with each other.
The repulsive force that pushes 0 back to the neutral point urges the blade portions 19 and 21 at the contact point P so as to closely contact each other.

When the blades 18, 20 are continuously bent from the contact point P on the base end side where the blade portions 19, 21 start contact with each other in order to form such a repulsive force, as a result, the blades 18, 20 from the center in the length direction to the tip 18
The shape is curved over b and 20b. For this reason,
As the contact point P moves toward the tip side, the blades 18, 2
Although the displacement of 0 becomes large, the leg portions 30a of the holding member 30,
Since the distance between the portions sandwiched between 30b and fixed, that is, the operating portions 18a and 20a also becomes large, the spring constant of the leaf spring becomes small. Therefore, the repulsive force generated is substantially constant regardless of the position of the contact point P.

Therefore, the scissors forceps 1 for an endoscope according to the present embodiment.
According to 0, even if the lengths of the blades 18 and 20 become long, from the base end portions 18a and 20a side to the tip end portions 18b and 20.
Each blade 1 over the entire length of the blades 18 and 20 up to b
It is possible for the blades 9 and 21 to contact with each other with a substantially constant urging force and effectively cut the portion to be cut at any position. In the above embodiment, the blades 18 and 20 are curved smoothly in opposite directions. Although the blades 18 and 20 have a curved shape, the blades 19 and 21 have curved shapes.
Any shape may be used as long as it is a curved shape that intersects at the point P from the open position shown in FIG. 2 to the closed position shown in FIG. 3, and is, for example, a curve formed of a single arc, a composite curve formed of a plurality of arcs, or a parabola. , A hyperbola, a bent straight line, or the like can be selected so as to exhibit appropriate elasticity depending on the thickness or width of the blade 18. Furthermore, it is possible to combine both blades 18 and 20 with the same curved shape or different curved shapes as needed for the scissors forceps 10. Also, the blade portions 19 and 2
It is obvious that the shape of 1 may not only be curved in the thickness direction together with the blades 18 and 20, but may be further curved in the width direction of the blades 18 and 20.

5 to 7 show some examples of such blade shapes. In the figure, the same parts as those in the above-mentioned embodiment are designated by the same reference numerals, and the description thereof will be omitted. FIG. 5 shows the tip portion 12 of the scissors forceps 10 for an endoscope according to the second embodiment, and the pair of blades 48, 50 is shown in a closed state. In the blades 48 and 50 of this embodiment, the thickness of the tip end side portion is thinner than that of the base end side portion.

The portions where the blade portions 49 and 51 are formed are formed to have a substantially constant thin structure from the portion that comes into contact with the blades 48 and 50 on the most proximal side to the tip portions 48b and 50b. A sufficient thickness is formed in the vicinity of the operation parts 48a and 50a on the base end side. Therefore, the blade 4
The overall shape of 8 and 50 is a stepped shape in which the blade portions 49 and 51 are one step thinner. It is preferable that the stepped portions 52 and 54 are formed with curved surfaces to prevent stress concentration.

In this second embodiment, the blades 48, 5
0, in particular, the portions where the blade portions 49 and 51 are arranged can obtain a sufficient stroke and low stress as a leaf spring, and the portions of the operating portions 48a and 50a that form the opening / closing mechanism 22 together with the links 38 and 40 and the driving member 42. Can be provided with sufficient strength, rigidity, and sufficient dimensions for forming a mechanism.

Therefore, according to the second embodiment, the blades 48 and 50 have the blade portions 49 and 51 arranged therein,
Since the thickness is changed between the operating portions 48a and 50a, and the thickness of the blade portions 49 and 51 is kept substantially uniform to form an appropriate spring constant, the elasticity and firmness are ensured. The drive mechanism described above can be configured.

In the third embodiment shown in FIG. 6, when used under observation with an endoscope in a body cavity, the entire shape of the tip side of the blades 56, 58 is changed so that the blades 56, 58 can be easily grasped in the observation visual field. It is bent in a state of being inclined to one side of 56, 58.

In this third embodiment, the blades 56, 5
Similar to the second embodiment, 8 is formed in a stepped shape having step portions 60 and 62, and the portion where the blade portion is formed forms a leaf spring shape called a quarter ellipse. With these blades 56, 58 closed, the operating parts 56a, 5
The tip portions 56b and 58b come into contact with each other at a position displaced to one side from the contact surface between 8a or the intermediate surface.

In the case of the third embodiment, the opening / closing drive mechanism 22 having proper elasticity and firmness is formed as described above, and the portions forming the blade portions of the blades 56 and 58 are divided into quarters. By having an elliptical shape, the visibility in the body cavity can be made excellent.

The tip portion of the scissors forceps 10 is limited in size in relation to a guide device such as a trocar that guides it into the body cavity. Since the insertion portion 14 (FIG. 1) is curved to the one side from the center line, the size of this inclination or bending is also restricted by such a guide device.

FIG. 7 shows a fourth embodiment, in which the blades 64 and 66 of this embodiment can be further curved even under such dimensional restrictions. The blades 64, 66 in this fourth embodiment are
Near the base end side where the blades contact each other, that is, near the contact start point, the blades 64 and 66 are once curved or tilted toward the same direction, and then the tilt is reversed to the original direction. As a result, a larger slope is formed. The part of the blade 64, 66 where the blade is formed is
It forms a leaf spring shape called a half ellipse.

In this embodiment, one blade 6 on the protruding side
4 has a stepped portion 68, and the other blade 66 has a cut-down portion 70. The lowering portion 70 is the blade 6
Prevents interference when opening and closing 4,66. In addition, it is preferable that the thickness of the blade forming portion of each of the blades 64 and 66 is formed such that the spring constants at the contact points of these blade portions are substantially equal.

As described above, by making the portions forming the blade portions of the blades 64 and 66 half-elliptical, the visibility in the body cavity can be further improved.
FIG. 8 shows a fifth embodiment of the present invention. In this embodiment, the force for contacting the blade portions of each blade is not formed by elastic deformation of the blade itself as in the first to fourth embodiments, but the holding member 30 or the leg portion of the holding member 30 is used. It is formed by elastic deformation of 30a and 30b.

As shown in FIG. 8, the leg portion 3 of the holding member 30.
The blades 74, 7 of
The operation portions 74a and 76a at the base end portion of 6 are rotatably held. The fulcrum screw 72 has a head portion whose diameter is enlarged on one end side of the shaft portion 72a, and the head portion has a male screw 72b.
And a spot facing 72c. Also, the holding member 30
An engaging hole 79a for slidably accommodating the shaft portion 72a of the fulcrum screw 72 is formed in one leg portion 30a, and the other leg portion 3a.
0b is formed with an engagement hole composed of a female screw portion 79b and a counterbore hole 79c. The fulcrum screw 7 is formed in the female screw portion 79b.
The male screw 72b of No. 2 is screwed, and the counterbore hole 79c is the counterbore 7.
2c is accommodated.

Therefore, the head portions 72b and 72c on one end side of the fulcrum screw 72 are firmly coupled to the leg portion 30b of the holding member 30, while the other end side of the fulcrum screw 72 is on the leg portion 30b.
In contrast, the fulcrum screw 72 can slide in the axial direction.

According to the scissors forceps of this embodiment, FIG.
In the state where the blades 74 and 76 shown in (4) are completely opened, the operating portions 74a and 76a are positioned closest to each other in the lateral direction. At this time, the end of the fulcrum screw 72 is fitted so as to completely fill the engagement hole 79a of the leg portion 30a.
The end surface of No. 2 is arranged substantially in the same plane as the outer surface of the leg portion 30a. Since the legs 30a and 30b of the holding member 30 are arranged substantially parallel to each other, the force for sandwiching the blades 74 and 76 is not large, but the contact point between the blades forms a fulcrum screw 72. Since it is close to, it is sufficient as a force for bringing the blade portions into contact with each other.

In the fully closed state of the blades 74 and 76 shown in FIG. 8B, the respective tip portions 74b and 76b are in contact with each other. The curved shapes of the blades 74 and 76 widen the distance between the leg portions 30a and 30b of the holding member 30,
The end surface of the fulcrum screw 72 is arranged in a state of being sunk in the engagement hole 79a. At this time, the leg portions 30a, 3 of the holding member 30
0b tries to return to the original state due to its elasticity, and generates a force in the direction of bringing the blade portions of the blades 74 and 76 into contact with each other via the operating portions 74a and 76a at the fulcrum screw 72 portion.

In the state shown in FIG. 8B, the distance between the leg portions 30a and 30b of the holding member 30 is the same as shown in FIG.
It is larger than the space indicated by, and therefore the force to close it is also large. However, since the contact point between the blade portions is long from the fulcrum screw 72, it is appropriate as a force for bringing the blade portions into contact with each other.

In the case where the blade portions of the blades 74 and 76 are brought into contact with each other by utilizing the elasticity of the holding member 30 as in the present embodiment, it is necessary to form the blades with a hard material, so that a large force can be applied by a slight displacement of the blades. The blades 74, 7 are appropriately biased even in a difficult controllable state in which the blades occur
It is possible to surely bring the blade portions of 6 into contact with each other. At this time, the urging force can be appropriately set to a required magnitude depending on the material, shape, size, etc. of the holding member 30. Therefore, the materials, shapes and dimensions of the blades 74 and 76 can be freely selected.

Therefore, according to this embodiment, since the blade portions of the blades 74 and 76 are brought into contact with each other by utilizing the elasticity of the holding member 30, the shape when the blades 74 and 76 are formed,
The dimensional freedom increases, and the holding member 30 can increase the stroke as a spring.

[0040]

As is clear from the above, according to the scissors forceps for an endoscope of the present invention, the force for bringing the blade portions into contact with each other acts on the blade, so that even if the length of the blade is long, the entire length of the blade is maintained. A sufficient shearing force can be generated.

[Brief description of drawings]

FIG. 1 is an overall view of scissors forceps for an endoscope according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing a state in which a blade is opened at a tip portion of the scissors forceps shown in FIG.

FIG. 3 is an explanatory diagram of a state in which the blade is closed.

FIG. 4 is an explanatory view showing a cross section of a part of a holding member that holds a blade.

FIG. 5 is an explanatory view showing the outline of the blade structure of the scissors forceps of the second embodiment.

FIG. 6 is an explanatory view showing the outline of the blade structure of the scissors forceps of the third embodiment.

FIG. 7 is an explanatory view showing the outline of the blade structure of the scissors forceps of the fourth embodiment.

FIG. 8 is an explanatory view showing the structure and operation of the holding member of the scissors forceps of the fifth embodiment.

[Explanation of symbols]

10 ... Scissors forceps, 18, 20 ... Blades, 18a, 20a
... Operating part, 19, 21 ... Blade part, 22 ... Opening / closing mechanism, 30 ...
Holding members, 30a, 30b ... Legs, 31 ... Slots, 3
2 ... fulcrum pin, 38, 40 ... link, 42 ... drive member,
P ... contact point.

Claims (1)

[Claims] 1. A scissors forceps for an endoscope having a pair of openable and closable blades, whose base ends are pivotally attached to each other and held by a holding member, wherein each of the blades is located laterally so as to intersect the respective blade portions. A scissors forceps having a curved shape, wherein the holding member has a biasing means for bringing the blade portions of the blades into contact with each other from the open position to the closed position.