JPH0460656B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a stone crushing forceps used for crushing a calculus generated within a body cavity.

[Prior Art] Stones occurring in organs such as the biliary tract and bladder have a negative impact on patients. This is especially true for enlarged stones.

Therefore, as a treatment for this, it has been conventionally practiced to use stone crushing forceps to crush the calculus generated within the body cavity and expel or remove it from the body cavity.

This type of calculus crushing forceps is equipped with a calculus-grasping basket made of a plurality of elastic wires at the tip of the operating wire, and the calculus-grasping basket is attached together with the operating wire to a flexible forceps with a hard part at the tip. A calculus is inserted into the sheath and the operating wire advances and retreats from the rear end.The calculus is grasped by a calculus grasping basket that protrudes from the tip of the flexible sheath. The basket is shrunk to smaller pieces.

Incidentally, such stone crushing forceps are provided with an operating section for opening and closing the stone grasping basket. Conventionally, such operation parts were manufactured using the
As shown in No. 34810, a slider mechanism is generally used. Specifically, as shown in FIG. 16, a shaft part b having a continuous finger hook part a is attached to the rear end of the flexible sheath c, and a slider d is provided on the shaft part b so as to be slidable freely. Connecting the rear end of the operating wire e to the slider d,
A structure is used in which a stone grasping basket f is connected to the tip of the operating wire e. Then, by moving the slider d, the operating wire e is pushed and pulled, and the flexible sheath c is moved from the insertion position where the stone grasping basket f is inserted into the flexible sheath c by pushing and pulling the operating wire e. The calculus grasping basket f is opened and closed by moving the sheath c to a protruding position. In this case, the stone grasping basket f is opened at the protruding position and closed at the insertion position, and after storing the stone in the basket f opened at the protruding position, the basket f is inserted into the flexible sheath. By moving the basket f to the insertion position in the container c, the basket f is closed and the basket f is reduced in size, thereby crushing the calculus into small pieces.

[Problems to be Solved by the Invention] However, although it is possible to pull the slider d toward the user's hand in order to crush a stone (not shown) in a device in which the operating section is configured with such a slider mechanism, it is difficult to prevent the stone from collapsing. At the moment when the grasping basket f is shattered due to the shrinkage change, the resistance of the slider d is instantly released and the momentum causes the stone grasping basket f to be rapidly drawn into the flexible sheath c. For this reason, the small stones crushed by the force of the blast are scattered and pose a danger of damaging the walls of the body cavity.

Furthermore, during the operation of pulling the slider d toward the user's hand during stone crushing work, the operating resistance gradually increases, and a reaction force is generated that tries to push the slider d back in the opposite direction to the operating direction. Therefore, if you remove your fingers from the slider d during the operation of pulling the slider d toward your hand, the grip on the stone will loosen.
For example, there is a risk that stones may fall out of the basket f, resulting in a problem of reduced operability.

This invention was made in view of the above-mentioned circumstances, and it is possible to prevent fine stones crushed during stone crushing work from scattering to the surrounding area, and it is possible to safely crush stones, and to improve operability. It is an object of the present invention to provide forceps for crushing stones that can be improved.

[Means for Solving the Problems] The present invention connects a calculus grasping basket made of a plurality of elastic wires to the distal end of an operating wire inserted into a flexible sheath having a hard part at the distal end, and an operating portion of the operating wire is provided on the proximal end side of the sheath, and the stone grasped by the stone grasping basket is pulled into the sheath together with the stone grasping basket as the operating wire is pulled in; In the calculus-crushing forceps for crushing a calculus, the operation section includes a reduction gear mechanism consisting of a plurality of gears with different numbers of teeth that reduce the operation force, and a reduction rotational force outputted from the reduction gear mechanism is applied to the operation section by moving the operation wire forward and backward. A rack is provided for converting the motion into a linear motion along the direction and transmitting it to the operation wire, and a check mechanism is provided on the rotating shaft of the reduction gear mechanism, which is composed of a reversal prevention gear and a stopper that meshes with the rotation shaft.

[Function] During stone breaking work, the operating force from the operating section is decelerated by a reduction gear mechanism, and the rack that pulls the operating wire is driven, and the amount of displacement of the rack and operating wire is reduced relative to the applied operating force. By making it extremely small, even if the resistance is released when the stone is crushed, the stone grasping basket will not be suddenly drawn into the flexible sheath due to the deceleration effect, and the finely crushed stone will be grasped. Prevents the basket from flying away due to movement. Furthermore, by amplifying the applied operating force and transmitting it to the rack to obtain a large crushing force with a light force, hard stones can be crushed easily. By preventing the rotating shaft of the reduction gear mechanism from rotating in the opposite direction, the rotating shaft of the reduction gear mechanism can be This is intended to improve operability by preventing rotation in the opposite direction.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 15.
This will be explained with reference to the figures.

FIG. 2 shows the overall structure of the forceps for stone fragmentation, in which 1 is a forceps body, 2 is a flexible sheath, and 3 is an operating section. The forceps body 1 includes a stone grasping basket 5 provided at the tip of a long operating wire 4. This calculus grasping basket 5 includes a plurality of elastic wires 6...
The both ends of the tip 7a and the tip 7b
At the same time, each elastic wire 6 is connected with, for example, two bent portions 7, thereby forming a cage-shaped expandable basket. In this case, the rear end side of each elastic wire 6... has a rear end tip 7b.
The rear end tip 7b extends in a long length to the rear of the
The following wire portions constitute the operating wire 4. Further, one of the elastic wires 6 forming the operating wire 4 extends longer than the other elastic wires 6. Also,
A locking body 9 that also serves as a locking portion is provided in the middle of the operating wire 4. The rear ends of other elastic wires 6 are connected to the long elastic wire 6 by this locking body 9.

On the other hand, the flexible sheath 2 is formed of, for example, a long tightly wound coil 11 covered with a covering material 10, and a calculus grasping basket 5 and an operating wire 4 are placed inside the flexible sheath 2. An insertable insertion passage 12 is formed. The tightly wound coil 11 has a hard part 13 at its tip, and a base 14 having a threaded part on its outer periphery at its rear end.
are provided for each. Therefore, the flexible sheath 2 allows the calculus grasping basket 5 to be inserted from the rear end side together with the operating wire 4, and the calculus grasping basket 5 can be inserted at the tip of the hard part 13.
can be placed freely and submersively. Note that 15 is a protective member that covers the vicinity of the rear end of the closely wound coil 11 on the proximal side of the flexible sheath 2.

In addition, FIG. 3 shows the operating section 3 which is the main part of this invention.
4 to 7 show the internal mechanism of the operating section 3, respectively.

In the figure, reference numeral 16a denotes an operating section main body formed by overlapping a rack casing 16 and a gear case 17. A rack 18 is housed inside the rack casing 16 of the operating section main body 16a. Furthermore, a reduction gear mechanism 19, which will be described later, is housed within the gear case 17 and the rack casing 16.

Moreover, the rack 18 has rack teeth 18 on the outer surface of the shaft body.
A plurality of a are arranged in parallel in a straight line. A through hole 20 is provided inside the rack 18 along the axial direction. In addition, the rack casing 16
A rack running path 21 is formed inside the rack casing 16 along its length. The rear end of the rack running path 21 is opened at the rear of the rack casing 16. A rack 18 is housed within this rack travel path 21 so as to be able to slide freely. Further, a locking door 22 is pivotally supported on the rear end surface of the rack 18, and the opening of the through hole 20 is held openably and closably by the locking door 22.

Further, a fixed ring portion 2 is provided at the distal end of the rack casing 16 and is connectable to the base 14 of the flexible sheath 2.
5 is provided. This fixed ring portion 25 is the 12th
As shown in the figure, the through hole 24 and the easy running path 21
It is arranged in series communication with the through hole 20 of the rack 18 through the front end of the rack. Therefore, the flexible sheath 2 through which the forceps body 1 is inserted can be connected to the operating section 3, and the operating wire 4 can be inserted into the fixed ring section 25, the through hole 24, and the through hole 20 in order to be engaged. By locking the stopper 9 to the locking door 22, both the rear end side of the operating wire 4 and the rack 18 can be connected along the forward and backward direction of the operating wire 4. As shown in FIG. 13, the locking door 22 has a slit 26 that prevents the locking body 9 from passing through, and a recess 27 that fits into the locking body 9 to prevent it from moving accidentally. A locking portion 28 is provided. Further, 29 indicates a pin for pivotally supporting the locking door 22.

Next, the reduction gear mechanism 19 will be explained.
As shown in FIG. 6, this reduction gear mechanism 19 has a driven shaft 30 rotatably mounted in the center of the large diameter portion of the gear case 17 and extending over the rack casing 16. Furthermore, a drive side shaft 3 extending over the rack casing 16 is located in the center of the small diameter portion of the gear case 17.
1 is rotatably attached. The driven shaft 30 and the driving shaft 31 are both arranged in a direction perpendicular to the rack 18. A small-diameter pinion gear 32 that engages with the rack teeth 18a of the rack 18 is provided on the shaft part installed in the rack casing 16 of the driven shaft 30, and a shaft part located in the large-diameter part. A large diameter gear 33 is attached to the top. Further, a large diameter gear 3 is disposed on the shaft portion located at the small diameter portion of the drive side shaft 31.
A small-diameter gear 34 that engages with the gear case 17 is provided, and a handle 35 is provided at the end of the drive-side shaft 31 that protrudes from the gear case 17. The operating force applied by a person from the handle 35 is decelerated while reaching each gear 34, gear 33, and pinion gear 32, so that the pinion gear 32 outputs a decelerated rotation. In this case, the rack 18 slides along the advancing and retreating direction of the operating wire 4 due to the engagement between the pinion gear 32 and the rack teeth 18a, and the deceleration rotational output output from the reduction gear mechanism 19 is caused by the rack 18 to move in a straight line. The motion is converted into motion and transmitted to the operating wire 4. As the operation wire 4 advances and retreats, the calculus grasping basket 5 can be opened and closed.

Further, as shown in FIG. 1, the drive shaft 31 of the reduction gear mechanism 19 is provided with a ratchet mechanism 53 consisting of a reversal prevention gear 51 and a stopper 52 that meshes with the reversal prevention gear 51. The stopper 52 of this ratchet mechanism 53 is rotatably provided around a support shaft 54. Furthermore, this ratchet mechanism 53 has an engaging pawl 52a at the tip of the stopper 52.
A spring member (not shown) is provided that always urges the gear 51 toward the tooth portion 51a of the anti-reversal gear 51. Further, each tooth portion 51a of the reversal prevention gear 51 has a drive side shaft 31 of the reduction gear mechanism 19 on one side, which engages the tip of the stopper 52 in a reverse rotation state, for example, rotating counterclockwise in FIG. An engagement surface that engages with the mating claw 52a is formed. In this case, the drive side shaft 31 is provided on the other side of each tooth portion 51a of the reversal prevention gear 51.
A guide surface is formed that guides the engagement pawl 52a at the tip of the stopper 52 in a direction of pushing it up from each tooth portion 51a against the biasing force of the spring member in a normal rotation state in which the stopper 52 rotates clockwise in FIG. ing. When the drive shaft 31 of the reduction gear mechanism 19 rotates clockwise in FIG.
Each tooth 51a is guided by the guide surface of each tooth 51a.
The drive side shaft 31 is pushed up from the top so that it can rotate freely. In addition, the reduction gear mechanism 19
When the drive-side shaft 31 rotates in the counterclockwise direction, the engagement pawl 52a at the tip of the stopper 52 engages with the engagement surface of each tooth 51a of the reversal prevention gear 51, and the drive-side shaft 31 rotates counterclockwise. Rotation is prevented.

Next, the operation of the above configuration will be explained.

When treating a stone in the bile duct using the stone crushing forceps configured as described above, for example, the forceps body 1 is first assembled into an endoscope (not shown).

That is, as shown in FIG. 8, a tube sheath 41 that is long and has a small outer diameter is used to inject a liquid such as a contrast medium, and is inserted into the calculus grasping basket 5 or the operating wire 4. , from the rear end side of the operating wire 4 to its tube sheath 41
A gripping part 43 having an operating pipe 42 protruding from the front part is inserted into the latter stage and fixed onto the operating wire 4.
Note that 44 is an injection port provided at the rear of the tube sheath 41. Here, the tip of the operating pipe 42 at this time is positioned by fitting into a recess 45 provided in the locking body 9 as shown in FIG. The operating wire 4 is held between both the knob 46 and the holding member 47 provided inside the grip component 43.

Then, the forceps body 1 combined with such a tube sheath 41 is inserted into the forceps channel of the endoscope.
The calculus grasping basket 5 is inserted into the tube sheath 41 in a retracted state. It should be noted that this operation is performed because the forceps body 1 can be easily inserted into the endoscope.

Thereafter, the insertion section of the endoscope is inserted into the body cavity, and the distal end of the insertion section is inserted into the bile duct, for example, from the duodenal papilla. When a calculus 50 is found with the endoscope, the grasping part 43 is moved forward to cause the calculus grasping basket 5 to protrude from the tip of the tube sheath 41, and the elastic wires 6 of the calculus grasping basket 5 are opened. The stone 50 is taken into the stone grasping basket 5 through the space. Thereafter, the loaded calculus 50 is gripped by the calculus gripping basket 5 by retracting the gripping member 43.

After grasping the stone using the tube sheath 41, the next step is to attach the large-diameter flexible sheath 2 and the operating section 3.

First, the tube sheath 41 is moved from the operation wire 4 whose movement is restricted by grasping the stone 50.
and remove the endoscope. Next, the flexible sheath 2 is inserted using the operating wire 4 remaining in the body cavity as a guide.
is inserted into the body cavity with the hard part 13 first. Here, the operating section 3 with the locking door 22 of the rack 18 opened.
Prepare. Then, the operating portion 3 is inserted through the rear end portion of the operating wire 4 extending from the base 14 of the flexible sheath 2. That is, the fixed ring part 2 of the operating part 3
5. Insert the operating wire 4 into the through hole 24 and then into the through hole 20 of the rack 18 in this order. Thereafter, the fixed ring part 25 of the operating part 3 and the base 14 of the flexible sheath 2 are connected by screwing as shown in FIG. The locking body 9 is pulled out, the locking door 22 is closed, and the locking body 9 is fitted into the recess 27 on the locking door 22 through the slit 26 as shown in FIG. FIG. 11 shows the assembled state of the entire stone-crushing forceps thus assembled.

As a result, as shown in FIG.
A flexible sheath and an operating section 3 are arranged in this order behind the calculus grasping basket 5 which is grasped. Thereafter, when the handle 35 is slowly rotated clockwise, the rack 18 is slid rearward by the rotation reduced by the reduction gear mechanism 19, and the operating wire 4 is pulled. Thus, by reducing the size of the stone grasping basket 5, the stone 50 is tightened and the 15th
The bond 50 will be broken into pieces as shown in the figure.

Here, in the case of such crushing, conventionally, 5 stones were
It has been pointed out that the moment the stone 0 is crushed, the stone grasping basket 5 moves rapidly and the small stones 50 are scattered, but this invention can solve this problem.

That is, the rack 18 that pulls the operating wire 4 is driven by the reduced operating force from the reduction gear mechanism 19. This means that the amount of backward displacement of the rack 18 and the operating wire 4 is extremely small relative to the applied operating force. Therefore, even if the resistance is released when the stone 50 is crushed, the stone grasping basket 5 will not move rapidly, that is, will not be drawn into the flexible sheath 2 due to the deceleration effect. Therefore, the finely crushed stones 50 are not scattered by the movement of the stone grasping basket 5.

Therefore, the stone 50 can be safely crushed while avoiding the risk of damage to the body cavity wall. Moreover, the structure in which the rack 18 is driven by such a reduction gear mechanism 19 has the advantage that a large crushing force can be obtained with a light force because the applied operating force is amplified and transmitted to the rack 18. Even sticky and hard stones 50 can be easily crushed.

Furthermore, the ratchet mechanism 53 consisting of the reversal prevention gear 51 and the stopper 52 that meshes with it can prevent the drive shaft 31 of the reduction gear mechanism 19 from rotating in the opposite direction.
When a rotational force in the opposite direction is generated on the drive side shaft 31 of the reduction gear mechanism 19 due to the resistance when crushing the
5 can be prevented from rotating in a direction opposite to the operating direction, thereby improving operability.

Note that this invention is not limited to the above embodiments.

For example, in the above embodiment, the stone was crushed using human power, but instead of human power, a drive source such as a motor may be used to crush the stone.

Further, in the above embodiment, the ratchet mechanism 53 is attached to the driving shaft 31 of the reduction gear mechanism 19, but the driven shaft 31 of the reduction gear mechanism 19
0 may be equipped with a ratchet mechanism 53.

Furthermore, it goes without saying that various other modifications can be made without departing from the gist of the invention.

[Effects of the Invention] According to the present invention, a reduction gear mechanism including a plurality of gears with different numbers of teeth that reduce the operation force in the operating section, and a reduction rotation output outputted from this reduction gear mechanism are provided in the forward and backward directions of the operation wire. In addition to providing a rack for converting linear motion along the axis and transmitting it to the operating wire, a check mechanism consisting of a reversal prevention gear and a stopper that meshes with the rotating shaft of the reduction gear mechanism is installed, so that it can be easily crushed during stone crushing work. It is possible to prevent the small stones that have formed from scattering into the surrounding area, and it is possible to safely crush the stones, and to improve the operability.

[Brief explanation of the drawing]

Figures 1 to 15 show one embodiment of the present invention, in which Figure 1 is a perspective view showing a check mechanism of a reduction gear mechanism, Figure 2 is an exploded view of forceps for crushing stones, and Figure 3 is a rear view of the operation unit, and Figure 4 is the - of Figure 2.
Figure 5 is a cross-sectional view taken along the - line in Figure 2, Figure 6 is a cross-sectional view taken along the - line in Figure 3, Figure 7 is a cross-sectional view taken along the - line in Figure 3, and Figure 8 is for stone crushing. A vertical cross-sectional view showing the combined state of the forceps, FIG. 9 is a vertical cross-sectional view of the main part showing the state in which the tip of the operating pipe is fitted into the recess of the locking body, and FIG. 10 shows the state in which the gripping parts are attached. FIG. 11 is a longitudinal sectional view of the main parts, FIG. 11 is a longitudinal sectional view showing the assembled state of the forceps for stone fragmentation, FIG. 12 is a longitudinal sectional view showing the connection structure between the flexible sheath and the operating section, and FIG. 13 is the operating section. Sectional view showing the locking door of the section, No. 14
15 is a side view showing a calculus being gripped by forceps for crushing a calculus, FIG. 15 is a side view showing a calculus being crushed by forceps for crushing a calculus, and FIG. 16 is a sectional view showing a conventional forceps for crushing a calculus. 2... Flexible sheath, 3... Operating unit, 4... Operating wire, 5... Basket for grasping calculus, 6...
Elastic wire, 13...hard part, 18...rack,
19... Reduction gear mechanism, 51... Reversal prevention gear,
52... Stopper, 53... Ratchet mechanism (return mechanism).

Claims (1)

[Scope of Claims] 1. A calculus grasping basket made of a plurality of elastic wires is connected to the distal end of a manipulation wire inserted into a flexible sheath having a hard part at the distal end, and a calculus grasping basket made of a plurality of elastic wires is connected to the proximal end of the sheath. An operating section for the operation wire is provided on the side of the operation wire, and the calculus grasped by the stone grasping basket is pulled into the sheath together with the stone grasping basket as the operating wire is pulled in, and the stone is crushed. In the forceps for calculus fragmentation, the operating portion is provided with a reduction gear mechanism consisting of a plurality of gears with different numbers of teeth that reduce the operating force, and a reduction rotational force output from the reduction gear mechanism is applied to linear movement along the forward and backward direction of the operation wire. A forceps for crushing a calculus, characterized in that a rack is provided for transmitting the information to the operating wire, and a check mechanism is provided on the rotating shaft of the reduction gear mechanism, which includes a reversal prevention gear and a stopper that meshes with the reversal prevention gear. .