CN100425206C - Taper sleeve type iso-radius contractor for cylindrical reticular stent - Google Patents

Abstract

The invention relates to a stent retractor, in particular to a tapered sleeve type cylindrical mesh stent isometric retractor. Cone-sleeve-type cylindrical mesh bracket equal-diameter shrinker, including taper sleeves, N equally divided guide cone surface rails are arranged in the cone sleeves, a fan-shaped block is provided in each guide cone surface track, and N guide cone surface tracks are provided. The tapered track forms a truncated cone shape, one end is the large end of the tapered sleeve, and the other end is the small end of the tapered sleeve; the driving device connected with the tapered sleeve. According to the mechanical characteristics of the cylindrical mesh support structure, the design can change the diameter continuously arbitrarily, and at the same time, the conical fan-shaped mechanism only has radial force on the compressed support, and produces uniform radial force to act on the outer cylindrical surface of the cylindrical mesh support. on, making it shrink isometrically.

Description

Taper sleeve type cylindrical mesh bracket isometric shrinker

technical field

The invention relates to a stent retractor, in particular to a tapered sleeve type cylindrical mesh stent isometric retractor.

Background technique

Human vascular diseases such as coronary artery stenosis, cerebrovascular embolism, and hemangioma have long been treated with drugs or traditional surgery. Since the introduction of biomedical engineering technology, various types of cylindrical mesh stents developed based on biomedical engineering science have been widely used in the treatment of the above diseases and have shown their superior efficacy. In the application of this biomedical engineering technology, an important key technology is to shrink the cylindrical mesh stent isometrically onto the balloon delivery system, so that the cylindrical mesh stent can be accurately delivered to the lesion by using the balloon delivery system, and Position it on the inner wall of the blood vessel. The success of this key technology has a very important impact on the medical effect. The current technology uses simple hand tools, which can easily cause non-isometric shrinkage or distortion of the cylindrical mesh stent. Cannot meet the requirements of biomedical engineering design.

Contents of the invention

The purpose of the present invention is to address the defects of the prior art, and provide a technical key to solve the isodiametric shrinkage of the tapered sleeve-type cylindrical mesh stent, that is, shrink the cylindrical mesh stent isometrically to the delivery balloon according to the design requirements of biomedical engineering, During the tightening process, all radial forces on the entire cylindrical surface of the bracket are uniform, no distortion occurs, and the performance of its original design and manufacture is maintained.

Cone-sleeve-type cylindrical mesh bracket equal-diameter shrinker, including taper sleeves, N equally divided guide cone surface rails are arranged in the cone sleeves, a fan-shaped block is provided in each guide cone surface track, and N guide cone surface tracks are provided. The tapered track forms a truncated cone shape, one end is the large end of the tapered sleeve, and the other end is the small end of the tapered sleeve; the driving device connected with the tapered sleeve;

The driving device is composed of a cylinder block, a push piston connected to the large end of the taper sleeve, a push rod connected to the small end of the taper sleeve to reset the sector, a cylinder head, an air inlet, and an exhaust port;

The push rod is connected with a compression spring;

Each of the push rod and the push piston is provided with a gripper;

The holder is composed of two tapered clamping blocks and a screw gland;

Disc spring grooves are provided on both sides of the fan-shaped block, and disc springs are arranged in the disc spring grooves;

There are 8 guide tapered tracks.

The manufacturing method of the cone-sleeve-type cylindrical mesh support equal-diameter shrinker is provided with N equally divided guide cone surface tracks in the cone sleeve, and a fan-shaped block is provided in each guide cone surface track, and N guide cone surface tracks are provided. The surface track forms a truncated cone shape, one end is the large end of the taper sleeve, and the other end is the small end of the taper sleeve. When the fan-shaped block is located at the large end of the taper sleeve to form a closed shape, a hole is processed in the center, and the aperture D=d+s (d= The required diameter of the cylinder mesh support after tightening), and reduce both sides of the fan-shaped block equally by s/2, so that an equal gap s=(D-d)π/8 is maintained between each fan-shaped block;

Said N is 8.

Advantages and effects of the present invention: the tapered sleeve type cylindrical mesh bracket isometric shrinker has the following unique advantages:

1. As long as the manufacture meets the design requirements, the principle of the invention makes the cylindrical mesh support and its system not subject to any additional force during the isometric compression process, ensuring that the cylindrical mesh support is only affected by the diameter of the cylindrical arc surface in the sector block. To ensure that the isodiametric shrinkage of the cylindrical mesh stent meets the technical performance requirements of the original design and manufacture.

2. The curvature of the inner cylindrical arc surface of the fan-shaped block is equal to that of the outer cylindrical surface of the compressed cylindrical mesh support at the initial stage of compression, and the cylindrical arc surface completely coincides with the outer cylindrical surface of the support. The area of the outer cylindrical surface of the bracket uniformly subjected to the radial compression force reaches more than 90%. During the tightening process, the curvature of the outer cylindrical surface of the bracket decreases gradually, and both sides of the arc-shaped inner cylindrical surface of the fan-shaped block gradually separate from the outer cylindrical surface of the bracket. At the end of the tightening, according to theoretical calculations, the separation gap between the inner cylindrical arc surface of the sector block and the two ends of the outer cylindrical surface of the bracket is 0.02mm, which decreases to only 0.004mm at the 20° angle between the cylindrical arc surface. Considering the elastic deformation of the cylindrical mesh support during the tightening process, it can be considered that the application of this invention technology can make the outer cylindrical surface of the cylindrical mesh support consistent with the inner cylindrical arc surface of the compressor sector during the entire tightening process . Among the currently known isometric shrinkage techniques of cylindrical mesh stents, there is no one that reaches this level.

3. Since the invention adopts electric signal control technology, it has good interface performance with numerical control technology. Cylindrical mesh stents are usually made of medical stainless steel tubes with a wall thickness of 80-116um and a diameter of 1.6mm through CNC laser precision engraving. Its length ranges from 20-45mm, depending on the patient's signs and lesion site requirements.

The design structure of the cylindrical mesh stent is strictly based on the calculation data of vascular dynamics, biomechanics, and elastic mechanics, and is designed by computer aided design. Its design ensures that the radial tension of the cylindrical mesh support is uniform in all directions, and the tolerance is less than 0.1%. The overall design and laser precision processing technology ensure that the cylindrical mesh stent has good intravascular pushability, flexibility and bending of blood vessels. The purpose of this invention is to study the technical key to solve the isodiametric shrinkage of the cylindrical mesh stent, that is, shrink the cylindrical mesh stent isometrically to the delivery balloon according to the design requirements of biomedical engineering, and make the stent expand in the entire circle during the tightening process. All radial forces on the surface of the cylinder are uniform, no distortion occurs, and the performance of its original design and manufacture is maintained.

According to the mechanical characteristics of the cylindrical mesh support structure, the design can change the diameter continuously arbitrarily, and at the same time, the conical fan-shaped mechanism only has radial force on the compressed support, and produces uniform radial force to act on the outer cylindrical surface of the cylindrical mesh support. on, making it shrink isometrically.

As shown in the figure, according to the mathematical principle, divide the frustum into 8 equal parts to form 8 fan-shaped blocks. When the fan-shaped block is positioned at the large end of the taper sleeve and becomes closed, a hole is processed in the center, and the aperture D=d+s (d=the required diameter of the cylindrical mesh support after tightening). And reduce s/2 equally on both sides of the fan-shaped block, so that an equal gap s=(D-d)π/8 is maintained between each fan-shaped block (as shown in Figure 2). When the 8 sectors move synchronously along the track cone to the small end of the tapered sleeve, the sector gaps are closed, and the diameter of the central hole is reduced to d=D-s (as shown in Figure 3).

Description of drawings

Fig. 1 is a schematic diagram of the structure of the present invention; Fig. 2 is a sectional view of the large end of the C-C direction of the frustum of the present invention. Fig. 3 is the sectional view of B-B of the present invention to the small end of the frustum of the cone; Fig. 4a is the enlarged view of the sector block of the present invention; Fig. 4b is the sectional view of the sector block A-A of the present invention; Fig. 5 is the sectional view of the tapered clamping block of the present invention Schematic diagram of the structure; Figure 6 is a schematic diagram of the push piston of the present invention; Figure 7 is a schematic diagram of the structure of the push rod of the present invention; Figure 8 is a schematic diagram of the structure of the mesh support; Figure 9 is a schematic diagram of the state of use of the mesh support.

In the figure, taper sleeve 1; cylinder block 2; sector block 3; push rod 4; push piston 5; cylinder head 6; compression spring 7; holder 8; Disc spring groove 12; air inlet 13; exhaust port 14; balloon 15; bracket 16.

Detailed ways

In this embodiment, the guide tapered track divided into 8 equal parts is taken as an example. The technical scheme and structural features of the tapered sleeve type cylindrical mesh support isometric shrinker are as follows: the tapered sleeve 1 is equipped with 8 guiding cone tracks, and the cone track is equipped with 8 fan-shaped blocks 3, the cone track, the fan-shaped block It is uniformly and precisely machined, and its external dimensions and center hole dimensions are all set within extremely small tolerances. Both sides of sector block 3 are provided with disc spring groove 12, and disc spring 11 is arranged in disc spring groove 12, and 8 sector blocks 3 under the effect of disc spring 11 force, fit on the taper sleeve guide rail all the time and slide. A push rod 4 and a push piston 5 are respectively arranged at its two ends. In order to ensure that the cylindrical mesh support is always in the center of the cylinder surrounded by 8 sector blocks during compression, an automatic centering gripper 8 is provided on the push rod 4 and the push piston 5 respectively, and the gripper 8 is composed of Two halves of tapered clamping blocks 9 and screw gland 10 constitute. This design structure ensures that the holder 8, the push rod 4, the push piston 5, and the sector block 3 can move in the horizontal direction synchronously. It is also ensured that no relative movement occurs between the cylindrical mesh support system on the holder 8 and the constrictor.

The push piston 5 is pushed by the compressed air in the cylinder formed by the cylinder block 2 and the cylinder head 6 . The push rod 4 is pushed by a compression spring 7 . The control solenoid valve is turned on under the action of the incoming signal, compressed air enters the cylinder from the air inlet 13, and pushes the piston 5, the sector block 3 and the push rod 4 to move to the small end of the taper sleeve together, and the compression spring 7 is compressed at this time. While moving horizontally, the eight sector blocks 3 are moved radially by the radial component force of the inclined surface of the guide rail of the taper sleeve, and at the same time, the arc shape of the inner cylindrical surface exerts a radial force on the bracket. The diameter of the cylindrical surface enclosed by the center decreases continuously, and finally reaches the diameter d required for the tightening of the cylindrical mesh support.

When the bracket tightening is completed, the incoming signal of the control solenoid valve is canceled, the pressure in the cylinder is discharged from the exhaust port 14, and the push rod 4 pushes the sector block 3 and the push piston 4 to return to the large end of the taper sleeve under the pressure of the compression spring 7. The diameter of the center hole of the sector envelope increases to d+s.

Claims (7)

1, taper sleeve type iso-radius contractor for cylindrical reticular stent, comprise tapered sleeve (1), it is characterized in that in tapered sleeve (1), being provided with the guiding conical surface track of N five equilibrium, in each guiding conical surface track, be provided with a secter pat (3), N guiding conical surface track constitutes the frustum shape, one end is the big end of tapered sleeve (1), and the other end is tapered sleeve (a 1) small end; The driving device that is connected with tapered sleeve (1) is by cylinder block (2), the promotion piston (5) that is connected with the big end of tapered sleeve, and the push rod (4) that secter pat (3) is resetted be connected with the tapered sleeve small end, cylinder head (6), air inlet (13), air vent (14) constitutes.

2, taper sleeve type iso-radius contractor for cylindrical reticular stent according to claim 1 is characterized in that described push rod (4) is connected with compression spring (7).

3, taper sleeve type iso-radius contractor for cylindrical reticular stent according to claim 1 and 2 is characterized in that described push rod (4) and promotes respectively being provided with clamper (8) on the piston (5).

4, taper sleeve type iso-radius contractor for cylindrical reticular stent according to claim 3 is characterized in that described clamper (8) is to be made of two taper fixture blocks (9) and spiral cover (10).

5, taper sleeve type iso-radius contractor for cylindrical reticular stent according to claim 1 is characterized in that the both sides of described secter pat (3) are provided with dish spring groove (12), is provided with dish spring (11) in dish spring groove (12).

6, taper sleeve type iso-radius contractor for cylindrical reticular stent according to claim 1 is characterized in that described guiding conical surface track is 8.

7, the manufacture method of taper sleeve type iso-radius contractor for cylindrical reticular stent, it is characterized in that in tapered sleeve (1), being provided with the guiding conical surface track of 8 five equilibriums, in each guiding conical surface track, be provided with a secter pat (3), 8 guiding conical surface tracks constitute the frustum shape, one end is the big end of tapered sleeve (1), the other end is tapered sleeve (a 1) small end, being positioned at the big end of tapered sleeve at secter pat (3) becomes under the closed form, process a hole at the center, aperture D=d+s, d=cylinder network tightens the diameter that the back requires, and secter pat both sides equalization is reduced s/2, makes to keep impartial gap s=(D-d) π/8 between each secter pat.

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