Pre-stressing devices incorporating materials subject to stress softening
AssigneeSulzer Carbomedics Inc.
InventorsEdward J. Sarnowski, Riyad E. Moe, Donald W. James
Life of this patent
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Abstract
A method and apparatus for pre-stressing devices incorporating materials subject to stress softening is disclosed, as well as the resulting device. The method includes fabricating a heart valve with an inflow side and an outflow side. At least a portion of the heart valve includes a material subject to stress softening. The material experiences stress when a pressure differential occurs between the inflow side and the outflow side of the valve. The method includes creating a stress in the material prior to implantation in order to stabilize the stress/strain response of the material prior to implantation.
Claims26
A method for manufacturing a prosthetic heart valve, comprising the steps of:
- fabricating a heart valve, the valve having an inflow side and an outflow side, at least a portion of the heart valve comprising an elastomer material subjected to stress softening, the material experiencing stress when a pressure differential occurs between the inflow side and the outflow side;
- and
- creating the stress in the material prior to use.
A method for manufacturing, a heart valve, the heart valve having at least a portion that includes an elastomer material subject to stress softening comprising the steps of:
- pre-stressing the elastomer material subject to stress softening prior to use.
A method for pre-stressing a tri-leaflet heart valve to meet a performance requirement, the method comprising the steps of:
- providing the heart valve having an inflow side and an outflow side, the heart valve comprising an elastomer portion subject to stress softening;
- creating a stress in the elastomer portion by providing a pressure differential between the inflow side and the outflow side;
- repeating a predetermined number of cycles;
- raising the stress to a predetermined amount;
- and
- lowering the stress to cause the heart valve to meet the performance requirement.
Dependencies are inferred from the claim text.