Method of fabricating seams in a bioprosthetic heart valve
A method of sewing preserved animal tissue to a manmade work piece that forms a part of a prospective bioprosthetic heart valve. The method utilizes a needle having an attached suture length and also having a relative object visibility of less than 0.8 relative to a standard straight surgical needle. Also, this needle has a volume of less than 7 mm 3 and a surface area of less than 70 mm 2 , is formed entirely of 300 series stainless steel, and has an eye, and the suture length is threaded through the eye. The needle having an attached suture length is used to manually sew the animal tissue to the manmade work piece that forms a part of the prospective bioprosthetic heart valve, while maintaining sufficient optical closeness to maintain the visibility of the needle.
1. A method of sewing preserved animal tissue to a manmade work piece that forms a part of a prospective bioprosthetic heart valve, comprising:
a) providing a straight needle having an attached suture length, said needle having a relative object visibility of less than 0.8 relative to a standard straight surgical needle, and that has a volume of less than 7 mm 3 and a surface area of less than 70 mm 2 , and is formed entirely of 300 series stainless steel, said needle having an eye and said suture length being threaded through said eye; and
b) using said needle having an attached suture length to manually sew said animal tissue to said manmade work piece that forms a part of said prospective bioprosthetic heart valve, while maintaining sufficient optical closeness to maintain the visibility of the needle.
2. The method of claim 1 , wherein said needle has a bottom defined by a point and an opposed top, and wherein said top defines an oval shape when viewed from above.
3. The method of claim 2 , wherein said needle becomes increasingly round as it extends from top to bottom.
4. The method of claim 1 , wherein said needle has a surface area of less than 65 mm 2 .
5. The method of claim 1 , wherein said needle has a surface area of less than 55 mm 2 .
6. The method of claim 1 , wherein said needle has a surface area of less than 50 mm 2 .
7. The method of claim 1 , wherein said needle is made of 302 stainless steel.
8. The method of claim 1 , wherein said needle is made of 304 stainless steel.
9. The method of claim 1 , wherein said work piece, tissue and needle are viewed under a mounted magnifier.
10. A method of sewing preserved animal tissue to a manmade structure, in the production of a bioprosthetic heart valve, comprising:
a) providing a needle having an attached suture length, said needle having a relative flexural strength of less than half that of a standard industrial needle, and has a volume of less than 7 mm 3 and a surface area of less than 70 mm 2 ; and
b) using said needle having an attached suture length to manually sew said animal tissue to said manmade work piece that forms a part of said prospective bioprosthetic heart valve, while not placing so much flexural stress on said needle that said flexural stress causes said needle to permanently deform or break.
11. The method of claim 10 , wherein said needle has a has a top that defines an oval shape, when viewed from above, and when the point of the needle is considered to be the bottom.
12. The method of claim 11 , wherein said needle becomes increasingly round as it extends from top to bottom.
13. The method of claim 10 , wherein said needle has a surface area of less than 60 mm 2 .
14. The method of claim 10 , wherein said needle has a surface area of less than 50 mm 2 .
15. The method of claim 10 , wherein said needle is made of 302 stainless steel.
16. The method of claim 10 , wherein said needle is made of 304 stainless steel.
17. A method of reducing incidence of repetitive motion work injuries among workers sewing together artificial heart valves from preserved animal tissue and manmade materials and experiencing muscle stress, as a consequence, said method comprising:
a) providing needles which have a relative visibility of less than 0.8 that of standard surgical needles and less than half the strength of standard industrial needles, and having a volume of less than 7 mm 3 ;
b) having said workers use said needles in sewing said bioprosthetic heart valves while maintaining sufficient optical closeness to ensure needle visibility and not stressing said needles so much that they permanently deform or break;
c) wherein said relatively smaller volume of said needles reduces the force needed to push said needles through said preserved animal tissue, thereby reducing repetitive motion work injuries.
18. The method of claim 17 , wherein said needle has a top that defines an oval shape, when viewed from above, and when the point of the needle is considered to be the bottom.
19. The method of claim 17 , wherein said needle has a surface area of less than 60 mm 2 becomes increasingly round as it extends from top to bottom.
20. The method of claim 17 , wherein said needle is made of 302 stainless steel.