Variable stiffness stent
AssigneeAdvanced Cardiovascular Systems, Inc.
InventorKent C. B. Stalker
Life of this patent
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Abstract
A stent having a structure differentiated in terms of its stiffness. Such differentiation is achieved with the use of a superelastic material that transitions between a relatively soft and malleable phase to a stiffer phase at a transition temperature that is adjustable. By differentially adjusting the transition temperature of different portions of the stent, a differentiation of the stiffness of the structure is achieved upon the stent being subjected to body temperature.
Claims38
A stent formed of a superelastic material, wherein such material transitions between a relatively soft and malleable phase and a relatively stiff phase at an adjustable transition temperature and wherein such stent is differentiated in terms of the transition temperature to which selected portions thereof have been adjusted such that the stent assumes a tapered configuration upon expansion whereby one end of the stent assumes a softer and more malleable state relative to the opposite end of the stent when the stent is subjected to body temperature.
A method of manufacturing a stent having a structure of differentiated stiffness, comprising:
- constructing a stent of superelastic material, wherein such material transitions between a relatively soft and malleable phase and a relatively stiff phase at an adjustable transition temperature and wherein the adjustable transition temperature is increased upon absorbing heat energy during heat treatment;
- and
- transferring differentiated amounts of heat energy to selected portions of the stent during heat treatment to differentially adjust the transition temperature of the portions such that the stent assumes a tapered configuration upon expansion.
A stent formed of a superelastic material, wherein such material transitions between a relatively soft and malleable phase and a relatively stiff phase at an adjustable transition temperature, comprising:
- a first portion of said stent, having a transition temperature adjusted so as to cause said first portion to be in a relatively stiff state when said stent is subjected to body temperature, wherein said first portion includes one end of the stent;
- and
- a second portion of said stent, having a transition temperature adjusted so as to cause said second portion to be in a relatively softer and more malleable state when said stent is subjected to body temperature, wherein said second portion includes an opposite end of the stent such that said stent assumes a tapered shape upon expansion.
A stent formed of a superelastic material, wherein such material transitions between a relatively soft and malleable phase and a relatively stiff phase at an adjustable transition temperature, comprising:
- struts that extend about the circumference of said stent and expand upon deployment, wherein said struts have transition temperatures selected so that struts at one end of the stent are in a relatively soft and malleable state and the struts at the other end are in a relatively stiff state such that said stent assumes a tapered shape upon expansion when said stent is subjected to body temperature;
- and
- spines that extend along a length of the stent and do not distort upon deployment of said stent, wherein selected spines have a transition temperature so as to cause said spines to be in a relatively softer and more malleable state when said stent is subjected to body temperature.
A tapered stent formed of a superelastic material, wherein such material transitions between a relatively soft and malleable phase and a relatively stiff state at an adjustable transition temperature, comprising:
- a first end of said stent, wherein said material has a transition temperature adjusted so as to cause said first end to be in a relatively stiff phase when said stent is subjected to body temperature and wherein said first end assumes a relatively small diameter upon deployment;
- and
- a second end of said stent, wherein said material has a transition temperature adjusted so as to cause said second end to be in a relatively softer and more malleable state when said stent is subjected to body temperature and wherein said second end assumes a relatively large diameter upon deployment.
A stent that upon deployment assumes a tapered shape having a large end and a small end, wherein such stent is formed of a superelastic material and wherein such material transitions between a relatively soft and malleable phase and a relatively stiff phase at an adjustable transition temperature, comprising:
- a first portion of said stent, wherein said material has a transition temperature adjusted so as to cause said first portion to be in a relatively stiff state when said stent is subjected to body temperature and wherein said first portion defines said small end of said tapered shape upon deployment;
- and
- a second portion of said stent, wherein said material has a transition temperature adjusted so as to cause said second portion to be in a relatively softer and more malleable state when said stent is subjected to body temperature;
- and wherein said second portion defines said large end of said tapered shape upon deployment.
Dependencies are inferred from the claim text.