Method for manufacturing stent using shape memory alloy wire, stent manufactured thereby, and jig for manufacturing same

Inventors

Shin, Kyong Min • HONG, Young ill • PARK, Se Ik

Assignees

Taewoong Medical Co Ltd

Abstract

The present invention relates to a stent that uses a shape memory alloy wire, the stent being an expansion device installed on a part of a body lumen, which is constricted, or which has been constricted, so as to widen the passage of the lumen in response to the lesion part. The purpose of the present invention is to provide a method for manufacturing a stent using a shape memory alloy wire such that the stent maintains a high degree of conformability in a bent portion of a body lumen in which the same is inserted while substantially improving rigidness and durability against continuously applied fatigue, a stent manufactured thereby, and a jig for manufacturing the same.

Core Innovation

The patent relates to manufacturing a stent using a shape memory alloy wire and provides a jig for the manufacturing. The jig includes a body formed in a vertically long cylindrical shape, and the circumference of the body forms a hollow part of the stent to be manufactured. Detachable pins interconnect the wire by being inserted at multiple split positions around the body in X and Y-axis directions to form an interconnected pattern on the jig.

The jig uses equator lines and dividing lines arranged to form a rhombic geometry in a cell grid pattern on the circumferential surface. The equator lines are divided by being spaced by a horizontal diagonal distance (Ph) in the X-axis direction from an arbitrary selected origin, and the equator lines are divided by a horizontal diagonal distance (Ph) at locations apart by a length (Ph1) bisecting the equator line. In a longitudinal direction, the dividing lines are divided by a length (Pv1) bisecting a reference dividing line and by a vertical diagonal distance (Pv) of a cell forming the rhombic geometry.

The interconnected pattern comprises a plurality of first stent loops and a plurality of second stent loops, connected by first connecting portions and second connecting portions, respectively. The first stent loops overlap the second stent loops such that the first connection portions overlap the second connecting portions, and the overlap is configured with an offset pitch (Pv2) by forming dividing lines at locations apart from a reference dividing line.

The patent describes that the manufacturing structure is aimed at improving fatigue resistance and conformability at bent lumen portions by reducing stress concentration at hook placement in the overlapped rhombic-cell structure. It further reports multi-axis stent fatigue test results showing improved expansion and shrinkage fatigue performance compared with a conventional configuration, and it states manufacturability and productivity advantages for the jig and stent manufacturing.

Claims Coverage

The document includes at least one independent claim directed to the jig structure for manufacturing a stent from a shape memory alloy wire, defining the jig geometry and the overlap of first and second stent loops via an offset pitch and overlapping connecting portions. The provided claims identify 3 inventive features.

The core coverage is the jig that uses rhombic equator-line/dividing-line grid spacing to determine pin insertion positions and to form an interconnected pattern of overlapping first and second stent loops, with overlap characterized by an offset pitch (Pv2) and overlapping connecting portions. Dependent refinements further specify offset-pitch double-connection behavior and pitch-length relationships, and include at least one narrowing condition excluding hook coupling between the first and second stent loops.

Stated Advantages

Documented Applications