| 摘要 |
<p>PURPOSE: To guarantee an organ to have a larger diameter by equippign a stent with a spiral coil made from a two-square memory alloy and a super- elastic state within a physiologic range accepted by some organs and a pliable state in which the diameter of the stent is smaller than the critical diameter although the diameter of the stent is larger than the critical one. CONSTITUTION: A stent consisting of a band 12 made from a two-square memory alloy is conditioned in a super-elastic state so as to have a form of a spiral coil 14, the diameter of which is close to that of a tubular organ. In a pliable stare the stent is conditioned so as to have a form of a spiral coil 16 in which the diameter of the stent is narrower than that in the super-elastic state. When the temperature of the band 12 rises higher than the first transfer temperature, the band 12 instantly changes into the form 14 that it should have in the super- elastic state. When the temperature drops lower than the second transfer temperature, the diameter of the stent becomes narrower and it takes the form 16 in the pliable state. When a catheter is taken into a tubular organ and heated, the diameter increases, pressurizing the wall of the organ.</p> |
