METHOD FOR MANUFACTURING A STENT HAVING SUPERIOR BENDING CHARACTERISTICS, AND STENT MANUFACTURED THEREBY

• US 20130282105A1
• Filed: 01/10/2012
• Published: 10/24/2013
• Est. Priority Date: 01/14/2011
• Status: Active Grant

• Current Assignee: Taewoong Medical Company Limited (Olympus Corporation)
• Original Assignee: Taewoong Medical Company Limited (Olympus Corporation)
• Inventors: Shin, Kyong Min
• Granted Patent: US 9,320,624 B2
• Time in Patent Office: Days
• US Class Current: 623/1.15
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2240/00 Manufacturing or designing of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
• CPC Class Codes: B21F 27/121 of tubular form, e.g. as reinforcements for pipes or pillars
• CPC Class Codes: B21F 45/008 of medical instruments, e.g. stents, corneal rings medical science A61

Abstract

Provided is a method for manufacturing a stent having a superior bending characteristic, in which a basic jig is employed to weave wires by alternating an obtuse angle and an acute angle so as to repetitively form starry cells in left and right portions and upper and lower portions of the stent, and in which the wires intersecting each other in the starry cells are allowed to freely move to provide the superior bending characteristic caused by flexibility in both the diametrical direction and lengthwise direction thereof, and the stent manufactured thereby. Thus, the stent can have a flexible bending characteristic and is prevented from being folded even when sharply bent after being coated.

Claims

1. A method of manufacturing a stent having a superior bending characteristic, in which a basic jig is used in which projecting pins are assembled at all transition points at which circumference dividing lines (a1, a2, a3, . . . , a13) and length dividing lines (b1, b2, b3, . . . , b17) set by equally dividing a circumference (W) and length (L) of a cylinder having the same diameter (Ø

) and length (L) as the stent to be manufactured cross one another, any one of the circumference dividing lines (a1, a2, a3, . . . , a13) of the basic jig is set as an arbitrary reference point (a1), and a wire is bent via the projecting pin of each transition point, travels from an upper portion to a lower portion while being joined crosswise, and forms predetermined cells, the method comprising;

(a) a downward wire bending process of moving a strand of wire from the reference point (a1) at a four-segment diagonal distance (4 l) in a downward direction, bending and moving the wire at a one-segment diagonal distance (1 l) at an acute angle and a two-segment diagonal distance (2 l) at an obtuse angle from the transition point in a zigzag pattern, forming acute angle bending vertexes and obtuse angle bending vertexes, and repeating this process to move the wire at a predetermined distance in the downward direction;

(b) a lower head forming process of bending and moving the wire from the transition point located in the downward wire bending process at the one-segment diagonal distance (1 l) at the acute angle again, bending and moving the wire at a four-segment diagonal distance (4 l) at an obtuse angle in a zigzag pattern, and repeating this process to form sexangular bending finishing ends so as to form a lower head having rhombic cells (C1);

(c) an upward wire bending process of bending and moving the wire from the transition point located in the lower head forming process at the one-segment diagonal distance (1 l) at the acute angle and the two-segment diagonal distance (2 l) at the obtuse angle in the zigzag pattern, forming the acute angle bending vertexes and the obtuse angle bending vertexes, and repeating this process to move the wire at a predetermined distance in an upward direction, whereby the wire is bent and moved upward at the transition point overlapped with the transition point of the downward wire bending process in a crossed state in the upward wire bending process of the wire, thereby forming a middle body in which starry cells (C2) are repetitively formed;

(d) an upper head forming process of bending and moving the wire from the transition point located in the upward wire bending process at the one-segment diagonal distance (1 l) at the acute angle again, bending and moving the wire at the four-segment diagonal distance (4 l) at the obtuse angle in the zigzag pattern, and repeating this process to form sexangular bending finishing ends so as to form an upper head having the rhombic cells (C1);

(e) a finishing connecting process of bending and moving the wire from the transition point located in the upward wire bending process at the one-segment diagonal distance (1 l) at the acute angle again, positioning the wire at the two-segment diagonal distance (2 l) at the obtuse angle once, and connecting a portion overlapped with the wire bent and positioned in the downward wire bending process by welding.

2. The method according to claim 1, wherein the downward wire bending process (a) includes disposing the wire at the projecting pin of the four-segment diagonal distance (4 l) from the reference point (a1), starting from the position of the projecting pin to bend and move the wire three times the one-segment diagonal distance (1 l) to the projecting pin in a zigzag pattern, bending and moving the wire three times the two-segment diagonal distance (2 l) to the projecting pin in a zigzag pattern again, and repeating this process to bend and move the wire at a predetermined distance in a downward direction.

3. The method according to claim 1, wherein the lower head forming process (b) includes bending and moving the wire from the transition point located in the downward wire bending process five times the one-segment diagonal distance (1 l) at the acute angle in the zigzag pattern, bending and moving the wire six times the four-segment diagonal distance (4 l) in the zigzag pattern again to form the three triangular bending finishing ends, bending and moving the wire two times the one-segment diagonal distance (1 l) to the transition point at the acute angle in the zigzag pattern again, and bending and moving the wire six times the four-segment diagonal distance (4 l) in the zigzag pattern again to form the remaining three triangular bending finishing ends, whereby the sexangular bending finishing ends are formed to obtain the rhombic cells (C1).

4. The method according to claim 1, wherein the upward wire bending process (c) includes bending and moving the wire from the transition point located in the lower head forming process seven times the one-segment diagonal distance (1 l) in the zigzag pattern, bending and moving the wire three times the two-segment diagonal distance (2 l) in the zigzag pattern again, bending and moving the wire two times the one-segment diagonal distance (1 l) in the zigzag pattern again, bending and moving the wire six times the two-segment diagonal distance (2 l) in the upward direction again, and repeating this process to bend and move the wire at a predetermined distance in the upward direction, whereby the obtuse angle bending vertexes are joined crosswise with the acute angle bending vertexes formed in the downward wire bending process, and the acute angle bending vertexes are joined crosswise with the obtuse angle bending vertexes, and the starry cells (C2) are repetitively formed and move upward at a predetermined distance, thereby forming the middle body.

5. The method according to claim 1, wherein the upper head forming process (d) includes bending and moving the wire from the transition point located in the upward wire bending process two times the one-segment diagonal distance (1 l) at the acute angle in the zigzag pattern again, bending and moving the wire six times the four-segment diagonal distance (4 l) in the zigzag pattern again to form the three triangular bending finishing ends, bending and moving the wire two times the one-segment diagonal distance (1 l) at the acute angle in the zigzag pattern again, and bending and moving the wire six times the four-segment diagonal distance (4 l) in the zigzag pattern again to form the remaining three triangular bending finishing ends, whereby the sexangular bending finishing ends are formed to obtain the rhombic cells (C1).

6. The method according to claim 1, wherein the finishing connecting process (e) includes bending and moving the wire from the transition point located in the upward wire bending process three times the one-segment diagonal distance (1 l) at the acute angle in the zigzag pattern, positioning the wire at the two-segment diagonal distance (2 l) at the obtuse angle once, and connecting the portion overlapped with the wire bent and positioned in the downward wire bending process by welding.

7. The method according to claim 3, wherein the lower head forming process (b) includes bending and moving the wire five times the one-segment diagonal distance (1 l) at the acute angle in the zigzag pattern, and forming a route along which the wires are overlapped to form the first triangular bending finishing ends.

8. The method according to claim 3, wherein the lower head forming process (b) includes bending and moving the wire two times the one-segment diagonal distance (1 l) at the acute angle in the zigzag pattern, and forming a route along which the wires are overlapped to form the remaining triangular bending finishing ends.

9. The method according to claim 5, wherein the upper head forming process (d) includes bending and moving the wire two times the one-segment diagonal distance (1 l) at the acute angle in the zigzag pattern, and forming a route along which the wires are overlapped to form the first triangular bending finishing ends.

10. The method according to claim 5, wherein the upper head forming process (d) includes bending and moving the wire two times the one-segment diagonal distance (1 l) at the acute angle in the zigzag pattern, and forming a route along which the wires are overlapped to form the remaining triangular bending finishing ends.

11. A stent having a superior bending characteristic, manufactured in the method according to claim 1, in which the rhombic cells (C1) formed at upper and lower portions by the crossed wires are formed at the upper and lower heads, the acute angle bending vertexes bent at the acute angle and the obtuse angle bending vertexes bent at the obtuse angle are joined crosswise between the upper and lower heads, the obtuse angle bending vertexes bent at the obtuse angle and the acute angle bending vertexes bent at the acute angle are crossed, and the middle body is formed so as to obtain the repetitive starry cells (C2).

12. The stent according to claim 11, wherein the repetitive starry cells (C2) are smoothly bent in such a way that the wire bent at the acute and obtuse angle by the acute and obtuse angle bending vertexes joined crosswise when expanded/contracted or bent in a lengthwise direction are crossed, and are expanded or contracted by widening or narrowing the acute and obtuse angle bending vertexes in a crossed state by rapid movement of the crossed wires, that the acute and obtuse angle bending vertexes of a bent direction are contracted, that the acute and obtuse angle bending vertexes of an opposite direction of the bent direction are pulled in the crossed state.

13. The stent according to claim 11, wherein the rhombic cells (C1) of the upper and lower heads are formed in two rows by the crossed wires.

14. The stent according to claim 11, wherein the stent is coated with a coating material on an inner or outer side thereof.