초록 ▼

Medical devices which are currently proposed to use elements made from shape memory alloys may be improved by the use of stress-induced martensite alloy elements instead. The use of stress-induced martensite decreases the temperature sensitivity of the devices, thereby making them easier to install

Medical devices which are currently proposed to use elements made from shape memory alloys may be improved by the use of stress-induced martensite alloy elements instead. The use of stress-induced martensite decreases the temperature sensitivity of the devices, thereby making them easier to install and/or remove.

대표청구항 ▼

[ I claim:] [1.]1. A medical device for insertion into a mammalian body, the device comprising(a) a hollow placement device;(b) a memory alloy element formed at least partly from pseudoelastic shape-memory alloy, the alloy displaying reversible stress-induced martensite at about body temperature suc

[ I claim:] [1.]1. A medical device for insertion into a mammalian body, the device comprising(a) a hollow placement device;(b) a memory alloy element formed at least partly from pseudoelastic shape-memory alloy, the alloy displaying reversible stress-induced martensite at about body temperature such that it has a stress-induced martensitic state and an austenitic state, the memory alloy element having (i) a deformed shape when the alloy is in its stress-induced martensitic state and (ii) a different unstressed shape when the alloy is in its austenitic state; and(c) a guide wire;the memory alloy element being within the hollow placement device, and the placement device being guidable by the guide wire, the hollow placement device stressing the memory alloy element at a temperature greater than the A.sub.s of the alloy so that the memory alloy element is in its deformed shape,wherein the memory alloy element can be extruded from the hollow placement device by the guide wire at a temperature greater than the A.sub.s of the alloy to transform at least a portion of the alloy from its stress-induced martensitic state so that the memory alloy element transforms from its deformed shape to its unstressed shape, and wherein the alloy is selected so that the transformation can occur without any change in temperature of the placement device or the memory alloy element.