Highly elastic stent and production method for highly elastic stent

Abstract

A highly elastic stent is made of an alloy that exhibits superelasticity at body temperature. At least a part of the highly elastic stent has such a property that load increases with displacement without exhibiting a distinct yield on a load-displacement curve obtained by a compression test and a bending test.

1 . A highly elastic stent made of an alloy that exhibits superelasticity at body temperature, wherein
 at least a part of the highly elastic stent has such a property that load increases with displacement without exhibiting a distinct yield on a load-displacement curve obtained by a compression test and a bending test.   
     
     
         2 . The highly elastic stent according to  claim 1 , wherein the alloy is any of Ti—Ni alloy, Co—Cr alloy, and stainless alloy. 
     
     
         3 . A method for producing the highly elastic stent according to  claim 1 , the method comprising:
 inserting a rod-shaped core metal into a hollow portion of a tube-shaped stent base;   maintaining, as needed, linearity of the stent base with the core metal inserted therein, and thereafter, cutting slot forming portions with a laser light while suppressing a heat effect by the laser light on a periphery of the slot forming portions so as to form slots and thus to make a stent; and   removing the core metal from the stent.   
     
     
         4 . The method for producing the highly elastic stent according to  claim 3 , the method further comprising expanding the stent from which the core metal has been removed to a predetermined diameter while performing heat treatment on the stent at 350° C. or below. 
     
     
         5 . The method for producing the highly elastic stent according to  claim 3 , wherein the slots are formed by cutting the slot forming portions with a laser that uses a water jet, which is formed so as to reach the stent base, as a waveguide of the laser light. 
     
     
         6 . The method for producing the highly elastic stent according to  claim 4 , wherein the slots are formed by cutting the slot forming portions with a laser that uses a water jet, which is formed so as to reach the stent base, as a waveguide of the laser light. 
     
     
         7 . A method for producing the highly elastic stent according to  claim 2 , the method comprising:
 inserting a rod-shaped core metal into a hollow portion of a tube-shaped stent base;   maintaining, as needed, linearity of the stent base with the core metal inserted therein, and thereafter, cutting slot forming portions with a laser light while suppressing a heat effect by the laser light on a periphery of the slot forming portions so as to form slots and thus to make a stent; and   removing the core metal from the stent.   
     
     
         8 . The method for producing the highly elastic stent according to  claim 7 , the method further comprising expanding the stent from which the core metal has been removed to a predetermined diameter while performing heat treatment on the stent at 350° C. or below. 
     
     
         9 . The method for producing the highly elastic stent according to  claim 7 , wherein the slots are formed by cutting the slot forming portions with a laser that uses a water jet, which is formed so as to reach the stent base, as a waveguide of the laser light. 
     
     
         10 . The method for producing the highly elastic stent according to  claim 8 , wherein the slots are formed by cutting the slot forming portions with a laser that uses a water jet, which is formed so as to reach the stent base, as a waveguide of the laser light.