Method for manufacturing yarn for vessel stent
AssigneeKabushikikaisha Igaki Iryo Sekkei
InventorKeiji Igaki
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Abstract
A stent for a vessel implanted in the vessel of the living body including a main body portion of the stent formed into a tube by a yarn formed of a biodegradable polymer exhibiting a shape memory function. The main body portion of the stent is shape-memorized to a size that can be inplanted in the vessel. The main body portion of the stent is implanted in the vessel of the living body as it is contracted in diameter by an external force, and is enlarged in diameter by being heated with the temperature of the living body. The main body portion of the stent is formed by winding a yarn formed of a biodegradable polymer in a tube form as the yarn is bent in a zigzag design. The main body portion of the stent is enlarged or contracted in diameter with the bends of the yarn as the displacing portions.
Claims18
A method for manufacturing a yarn for a vessel stent comprising the steps of:
- compressing and melting pellets formed of a biodegradable polymer,
- heating said pellets to a temperature in the vicinity of its melting point (Tm) or a temperature higher than its melting point and lower than its thermal decomposition point by a screw extruder,
- extruding said melted biodegradable polymer from a nozzle of said screw extruder to form a yarn, and
- bending said yarn in a zig zag design to constitute a tubular main body portion of said vessel stent to obtain said yarn for the vessel stent,
- said nozzle being controlled to have a temperature not higher than the melting point and not lower than the glass transition temperature of the biodegradable polymer.
A method for manufacturing a yarn for a vessel stent comprising the steps of:
- (A) obtaining a yarn made by the following process:
- (1) compressing and melting pellets formed of a biodegradable polymer,
- (2) heating said pellets to a temperature in the vicinity of its melting point (Tm) or a temperature higher than its melting point and lower than its thermal decomposition point by a screw extruder, and
- (3) extruding said melted biodegradable polymer from a nozzle of said screw extruder to form said yarn, and
- (B) bending said yarn in a zig zag design to constitute a tubular main body portion of
- said vessel stent to obtain said yarn for a vessel stent, said nozzle being controlled to have a temperature not higher than the melting point and not lower than the glass transition temperature of the biodegradable polymer.
Dependencies are inferred from the claim text.