JPH09149937A - Expanding/shrinking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expanding/shrinking device capable of switching the mode and expanding or shrinking a catheter easily, quickly, and accurately and having a simple structure. SOLUTION: This device for expanding or shrinking a balloon catheter is constituted of a cylindrical first outer tube 2, an inner tube slidably arranged on the lumen of a first outer tube 2, an inner tube shaft 5 connected to the end section of the inner tube 3 and carved with a thread 4 in a part thereof, a screw member 7 having a tread carried in the first outer tube 2 and engageable with the thread 4 of the inner tube shaft 5, a spring 8 fitted to the screw member 7, and a second outer tube 9 slidably fitted on the outer periphery of the first outer tube 2. The screw member 7 is partially protruded through the groove formed on the first outer tube 2. When one of the first and second outer tubes 2, 9 is slid, the engaged/released state between the screw member 7 and the thread 4 of the inner tube shaft 5 is selected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for expanding and contracting a balloon catheter used for angioplasty such as percutaneous transluminal coronary angioplasty (PTCA).

[0002]

2. Description of the Related Art In angioplasty such as PTCA, a balloon catheter is inserted into a narrowed blood vessel, the balloon is expanded at a high pressure of 6 atm or more to expand the narrowed portion, and then immediately. To contract and restart blood flow. In this way, the blood flow is restarted by rapidly repeating the expansion and contraction of the balloon part of the catheter inserted into the blood vessel, and then the catheter is taken out from the blood vessel. You can save time and effort. However, this procedure requires skilled techniques and requires rapid and accurate operation, especially when inflating and deflating the catheter. Generally, the dilatation / expansion device of the vasodilator catheter is in the form of a pressure gauge syringe having two actuation modes, a release mode and an engagement mode. In the release mode, the inner cylinder (piston) is inside the syringe outer cylinder.
Can be freely slid and used for inhaling fluid into the syringe, for rapidly expelling fluid from the syringe for inflating and deflating the balloon, and for inhaling fluid. On the other hand, in the engagement mode, the screw engraved on the inner cylinder shaft (piston shaft) is engaged with the threaded member carried by the outer cylinder, so that the inner cylinder is moved by pushing by hand. However, the axial movement is possible only by rotating the inner cylinder shaft. This mode is capable of achieving and maintaining the high pressure required to expand the balun catheter. Since it is difficult to achieve such a high pressure manually, it is performed by rotating the screw. Further, in this mode, the pressure can be finely adjusted (increased or decreased) while the catheter is expanded.

Among the conventional expansion / contraction devices, there are many types which are usually in the engagement mode and which are set in the release mode by pushing the switch. They do not require continuous pressing and holding of the switch to maintain the release mode, or the operation of pressing and holding is unnecessary, but when high pressure of 10 atm or more is applied,
Excessive force is required at the time of switching the mode (especially when shifting from the engaging mode to the releasing mode), and it is difficult to instantaneously contract the balun. Because it is complicated, there are problems with complicated operations,
It was very inconvenient to use.

[0004]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to provide a simple structure that can easily, quickly and accurately switch modes and expand / contract a catheter. It is to provide an expansion / contraction device.

[0005]

According to the present invention, a cylindrical first outer cylinder and an inner cylinder slidably arranged in an inner cavity of the first outer cylinder,
An inner cylinder shaft that is connected to an end of the inner cylinder and is partially threaded, a screw member that is carried in the first outer cylinder and that has a screw that can engage with the screw of the inner cylinder shaft, and the screw member A second outer cylinder slidably mounted on the outer circumference of the first outer cylinder, and the screw member partially projects through a groove provided in the first outer cylinder. The expansion / contraction device is characterized in that the engagement / release state of the screw member and the screw of the inner cylinder shaft is selected by sliding the outer cylinder.
The second member is a member with a screw whose part protrudes outside the first outer cylinder.
It is pressed (pressed) inward by the outer cylinder,
It will be released. Along with this, the spring mounted on the threaded member is compressed or expanded, displacing the position of the threaded member. As a result, the position of the screw member in the first outer cylinder is easily displaced by the sliding of the outer cylinder, and the screw of the threaded member is engaged with the screw of the inner cylinder shaft (engagement mode) by the displacement. Or release (release mode
It becomes possible to do.

When the spring is further compressed, the screw of the threaded member engages with the screw of the inner cylinder, and conversely, when the spring extends, the screw of the threaded member comes off the screw of the inner cylinder. In the case of a device having a specific action mechanism, as will be described later, the screw is unlikely to be displaced in the engagement mode, and conversely, the screw is easily removed in the release mode. As described above, according to the expansion / contraction device of the present invention, it is not necessary to continuously press the switch or the like in order to maintain the engagement / release mode, and the mode can be changed more easily, quickly and surely. You can expand and contract the catheter and catheter.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The expansion / contraction device of the present invention comprises a cylindrical first outer cylinder, an inner cylinder slidably arranged in the inner lumen of the first outer cylinder, and an end portion of the inner cylinder. And a screw member having a screw that is carried in the first outer cylinder and is engageable with the screw of the inner cylinder shaft, a spring attached to the screw member, and a first outer It is composed of a second outer cylinder slidably mounted on the outer circumference of the cylinder, and the screw member partially projects through a groove provided in the first outer cylinder. It is characterized in that the engagement / release state with the screw of the inner cylinder shaft is selected.

The mechanism of engagement / disengagement between the screw member and the screw of the inner cylinder shaft is selected by the sliding of the outer cylinder. As for its operating mechanism, the high pressure is maintained (difficult to shift the screw) and the engagement / release mode is selected. The following is preferable from the viewpoint of easy switching of the mode. That is, by sliding the outer cylinder, a screw member, a part of which protrudes outside the first outer cylinder, is pressed (inwardly) by the second outer cylinder, the spring is compressed by the pressing, and the spring is extended by releasing the pressing. Is. When the spring is compressed by pressing, the threaded member is displaced, the screw of the threaded member engages with the screw carved in the inner cylinder, and conversely, when the screw member is released from the pressing, the spring expands. However, in the expansion / contraction device having an action mechanism whereby the screw of the threaded member is disengaged from the screw of the inner cylinder, the screws are unlikely to be disengaged from each other in the engagement mode, and are unlikely to be displaced.
Further, when this action mechanism is adopted, the screw is hard to come off, so that it is not restricted by the shape of the screw. Therefore, the engagement mode
It is possible to choose a double-sided bevel screw that is easy to switch from the open mode to the open mode (easy to remove the screw). The double-sided tilted screw here is a screw in which both the left and right sides of the screw thread are tilted with respect to the axis as shown in FIG.
A screw thread inclination of 60 ° with respect to the axis is preferred.

Further, in the screw member or the second outer cylinder, when the outer cylinder comes into contact with the screw member, slipping easily occurs,
It is easy to use that at least a part of the area of the outer cylinder that comes into contact with the slide is formed in a curved shape or is formed in a taper so that the slide can be performed smoothly.

The direction and type of sliding of the outer cylinder (linear movement,
The rotational movement) is not particularly limited, and the slide may be linear movement in the axial direction of the inner cylinder axis, or may be rotational movement around the first outer cylinder.

Although the number of the screw members may be one, it is preferable that the screw members are composed of a plurality of two or more so as to prevent the displacement. In addition to metals, it is also possible to use synthetic resins with high wear resistance and high bending strength, such as 1000 kgf / cm2.
Those having the above bending strength are preferable. For example, polyacetal, nylon 66, or fiber reinforced plastic (FRP) is suitable.

[0012]

FIG. 1 shows an expansion / contraction device 1 embodying the features of the present invention. This device 1 for inflating and contracting a balun catheter is a cylindrical first outer cylinder 2, an inner cylinder (piston) 3 slidably arranged in the first outer cylinder inner cavity, and an inner cylinder 3 at the tip. Which is mounted on the inner cylinder shaft (piston shaft) 5, at least a part of which is screwed with a screw 4, and a screw member which is carried in the first outer cylinder 2 and has a screw 6 engageable with the screw 4 of the inner cylinder shaft. 7, a spring 8 mounted on the screw member 7, and a second outer cylinder 9 slidably mounted on the outer periphery of the first outer cylinder. The screw member 7 tends to expand outward due to the spring 8 (spring) attached thereto. The spring 8 may be a coil as shown in the figure or a leaf spring. Also, as shown in the figure,
A groove 10 is formed in the first outer cylinder 2 so that a part of the threaded member 7 can be projected. In a state where no external force is applied, the threaded member 7 passes through the groove 10 by a drag force of a spring, and a part thereof is formed. Is projected to the outside of the first outer cylinder 2.

Here, when the second outer cylinder 9 covering the outer periphery of the first outer cylinder 2 is slid on the first outer cylinder 2, a part of the threaded member 7 protruding from the first outer cylinder 2 becomes second. The inner wall of the outer cylinder 9 pushes the first outer cylinder 2 inward. Therefore, the screw member 7 expanded by the spring 8 is pushed back to the inside of the first outer cylinder, and the screw member 7 is compressed while compressing the spring 8.
Move the position of to the inside. (FIG. 2). The screw 6 of the moved screw member 7 engages with the screw 4 of the inner cylinder shaft. On the contrary, when the slide member is slid to remove the pressing force of the second outer cylinder against the screw member 7, the spring 8 is released, the screw member 7 expands outward, and the screw 6 is disengaged from the screw 4. As shown in FIG. 1, when the recess 11 is provided on the inner wall of the second outer cylinder 9, by sliding the second outer cylinder 9, the protruding portion 12 of the screw member 7 is fitted into the recess 11. When the protruding portion 12 is fitted in the recess 11, the spring 8 extends and the screw 6 and the screw 4 are disengaged from each other to be in the release mode. On the contrary,
As shown in FIG. 5, when the screw member 7 is pressed by the inner wall of the second outer cylinder 9, the spring 8 is compressed and the screws are engaged with each other to be in the engagement mode. Here, if a part of the area where the projecting portion 12 of the threaded member 7 and the recessed portion 11 contact each other is formed in a smooth curved shape so as to allow them to easily slip, or if formed in a taper, the outer cylinder Slides easily. It may be provided on the protruding portion side of the threaded member 7 or may be provided on the concave portion 11 side of the second outer cylinder.
Of course, both may be provided. Further, instead of providing the concave portion, the end portion 13 of the second outer cylinder 9 may be formed as a taper as shown in FIG. 3 so as to facilitate sliding.

As described above, the structure in which the screw 6 and the screw 4 are engaged by the compression of the spring 8 and the engagement between the screws is released by the extension of the spring 8 is the same as the shape of the screw described later. Relevant, but one of the advantageous features of the present invention. This mechanism works more effectively when selecting the engagement / disengagement mode used to expand and contract the barn catheter to high pressure. Hereinafter, the reason will be described.

As for the shape of the screw, a double-sided inclined screw in which both left and right sides of the screw thread are inclined with respect to the shaft as shown in FIG. 5 and one side of the screw thread as shown in FIG. Although there is a single-sided inclined screw whose other surface is perpendicular to the axis, the shape of the screw used in the expansion / contraction device for angioplasty is predominantly a single-sided inclined screw. This is mainly because of the reasons described below. Most of the existing expansion / contraction devices are usually in the engagement mode, and have a mechanism that allows the release mode only when necessary, and is released only when the switch is pressed to compress the spring. With this mechanism, as shown in FIG. 6, the screws are engaged with each other only by the reaction force F2 of the spring. When a high pressure is applied in the axial direction of the inner cylinder, the screw member 7 also receives the pressure F in the axial direction by the inner cylinder 5. The pressure F is dispersed in the direction in which the member 7 is expanded, and the spring resistance F2 alone cannot support the expanding pressure F1. (FIG. 7) That is, when the pressure rises, the screws are disengaged and slip. For this reason, the current expansion / contraction device employs a single-sided screw in which the pressure is less dispersed in the direction in which the screw member 7 is expanded. Disengagement of the screws is difficult for an operator who is not so easy and who is unfamiliar, especially when high pressure is applied. In the operation of expanding the blood vessel by repeating the inflation and contraction of the balloon catheter, the inability to make a smooth transition from the engagement mode to the release mode is a serious drawback that cannot be overlooked.

However, when the structure in which the screw 6 and the screw 4 are engaged with each other when the spring 8 is compressed and the extension of the spring 8 disengages the screws from each other as in the present invention, the above-mentioned structure is adopted. The problem of is solved. It is different from the current product in that the screws are not engaged by the reaction force of the spring due to compression, but the screw members are pressed by the pressing of the outer cylinder and the screws are engaged, so regardless of the shape of the screw. , Even if the pressure is high, the screws will not come off easily. in this way,
When the screw member is pressed (inwardly) by the slide of the outer cylinder, the spring is compressed, and the screw 6 of the threaded member engages with the screw 4 engraved on the inner cylinder to form an engagement mode. On the contrary, when the screw member is released from the pressing force, the spring expands, and accordingly, the screws are disengaged from each other to become the release mode. It is difficult for the screws to come off and slip off. Further, in the above-mentioned one, since the screw is not easily displaced when the action mechanism itself is engaged, it is not restricted by the shape of the screw. Therefore, it is possible to select the both-sided screw having a shape that can be easily removed (without adopting the one-sided screw that does not easily come off in the release mode), and the engagement and the release can be easily performed.

[0017]

With a simpler structure, it is possible to easily, quickly and surely perform mode switching and expand / contract the catheter.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a locking mode of an expansion / contraction device according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a release mode of the device of FIG.

FIG. 3 is a schematic view showing a release mode of the device according to another embodiment of the present invention.

FIG. 4 is a partial sectional view showing a screw on one side.

FIG. 5 is a partial cross-sectional view showing screws on both sides.

FIG. 6 is a schematic view showing a state in which one-sided screw and a threaded member are engaged with each other in a conventional device.

FIG. 7 is a schematic view showing a state in which a both-side screw and a threaded member are engaged with each other in a conventional device.

[Explanation of symbols]

 1. Expansion / contraction device 2. First outer cylinder 3. Inner cylinder 4. Screw (on the inner cylinder shaft) 5. Inner cylinder shaft 6. Screw (screw member) 7. Screw member 8. Spring 9. Second outer cylinder 10. Groove 11. Recess 12. Protruding portion 13. edge

Claims (11)

[Claims] 1. A device for expanding and contracting a balun catheter, comprising a cylindrical first outer cylinder, an inner cylinder movably arranged in an inner cavity of the first outer cylinder, and an inner cylinder of the inner cylinder. An inner cylinder shaft that is connected to an end and is partially threaded, a screw member that is carried in the first outer cylinder, and has a screw that can engage with the screw of the inner cylinder shaft, and that is attached to the screw member. And a second outer cylinder slidably mounted on the outer periphery of the first outer cylinder, and the screw member projects a part thereof through a groove provided in the first outer cylinder and slides one of the outer cylinders. The expansion / contraction device is characterized in that the engagement / release state of the screw member and the screw of the inner cylinder shaft is selected by doing so. 2. The screw according to claim 1, wherein the screw of the inner cylinder shaft is engaged with the screw of the screw member when the spring is compressed, and the screw is disengaged when the spring is extended. Expansion / contraction device. 3. The expansion according to claim 1, wherein the spring is compressed by pressing the screw member by the second outer cylinder, and the spring is released by releasing the pressing.・ Shrinking device. 4. The expansion / contraction device according to any one of claims 1 to 3, wherein a concave portion into which the protruding portion of the screw member is fitted is formed in the second outer cylinder. 5. The screw member or the second outer cylinder according to claim 1, wherein at least a part of a region in contact with the outer cylinder by sliding is formed in a curved shape. Expansion / contraction device. 6. The tape member according to any one of claims 1 to 5, wherein at least a part of a region of the screw member or the second outer cylinder which is brought into contact by sliding of the outer cylinder is formed on a taper. The expansion / contraction device described. 7. The expansion / contraction device according to claim 1, wherein the slide of the outer cylinder is in the axial direction of the inner cylinder shaft. 8. The expansion / contraction device according to claim 1, wherein the slide of the outer cylinder is a rotational movement around the outer cylinder. 9. The plurality of screw members are configured.
The expansion / contraction device described in any one of 8 to 8. 10. The screw member is 1000 kgf / cm.
The expansion / contraction device according to any one of claims 1 to 9, which is formed of a synthetic resin having a bending strength of 2 or more. 11. The expansion / contraction device according to claim 1, wherein the screw engraved on the screw member is a double-sided inclined screw.