Method of making unitized three leaflet heart valve

• US 4,265,694 A
• Filed: 01/22/1980
• Issued: 05/05/1981
• Est. Priority Date: 12/14/1978
• Status: Expired due to Term

• Current Assignee: United States of America As Represented By The Secretary of The Department of Health Education and Welfare
• Original Assignee: United States of America As Represented By The Secretary of The Department of Health Education and Welfare
• Inventors: Iriguchi, Norio, Boretos, John W.
• Primary Examiner(s): Weston, Caleb
• Application Number:
  US06/114,298
• Time in Patent Office: 469 Days
• Field of Search: 156/242, 156/245, 156/293, 156/294, 264/328, 3/1.5
• US Class Current: 156/242
• CPC Class Codes: A61F 2/2412 with soft flexible valve members, e.g. tissue valves shaped like natural valves check valves with flexible valve members in general F16K15/14
• CPC Class Codes: B29C 41/14 Dipping a core B29C41/10 takes precedence
• CPC Class Codes: F16K 15/147 the closure elements having specially formed slits or being of an elongated easily collapsible form
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device

Abstract

An artificial heart valve comprising a semi-rigid framework having three projecting symmetrical struts and open axially therethrough, as well as a polyurethane elastomeric membrane attached to the struts and constituting three leaflets, is formed by molding the framework, including the base and strut, using polyurethane resin; forming the elastomeric membrane, of polyurethane resin which is thin relative to the framework, and forming a thickened commissure along the leading edge of the membrane as well as reinforcing lines radiating from its base; then joining the framework with the elastomeric membrane using an adhesive cement so as to permanently bond the membrane to the framework.

Claims

1. A method of producing an artificial heart valve, comprising the steps of:

molding an artificial heart framework, including a base and struts, using polyurethane resin;

forming an elastomeric membrane, of polyurethane resin which is thin relative to said framework, and forming a thickened commissure along the leading edge of said membrane, and forming a plurality of lines, thicker than said membrane, radiating from the base of said membrane;

joining said framework with said elastomeric membrane using an adhesive cement, and permanently bonding said membrane to said framework.

2. A method according to claim 1, further comprising permanently bonding a suture ring to the base of said framework using solvent or adhesive cement.

3. A method of producing an artificial heart valve, comprising the steps of:

injection molding a framework using polyurethane, including a base and struts of the heart valve;

annealing said framework for relieving residual strains in said framework;

forming an elastomeric membrane having a base and a commissure area, of polyurethane thin relative to said framework, by solvent casting, using a first mandrel, and reinforcing the commissure area by building up a lip, thick relative to the thickness of said membrane, along the leading edge of said membrane, and forming a plurality of lines, thicker than said membrane, radiating from the base of said membrane;

drying said membrane to remove solvent therefrom;

peeling said membrane from said first mandrel;

orienting said framework over a second mandrel having a trileaflet design and coating said membrane with a polyurethane solvent;

placing said membrane over said second mandrel, on said framework;

applying solvent or adhesive cement, and pressure to a bond line between said membrane and said framework, until said membrane and framework are permanently bonded together;

removing said framework and membrane from said second mandrel;

permanently bonding a suture ring to the base of said framework using solvent or adhesive cement; and

drying the valve to remove said solvent

4. A method, according to claim 3, wherein said membrane and the completed valve are dried at 50°

C.

5. A method, according to claim 3, wherein the pressure applied to the boundary between said membrane and said framework is 15ps:

for 5 minutes to one hour at between 240° and

320°

F.

6. A method, according to claim 3, wherein said step of forming said elastomeric membrane by solvent casting comprises;

forming a solution containing polyurethane and a solvent;

removing all the air from said solution;

dipping a first mandrel in said solution at least once;

withdrawing said first mandrel from said solution so as to preclude trapping air in said solution.

7. A method, according to claim 3, further including;

removing all the air from the injection molded parts before said framework is formed by injection molding.

8. A method, according to claim 3, wherein said annealing takes place at between 200°

F. and 300°

F. for between 1 and 24 hours.

9. A method, according to claim 6, wherein said solvent is dimethyl acetamide, tetrahydrofuran, dimethly formamide or cyclohexanone.