Patent ID: 8394090

Claim:
A method for fusing a biological tissue, comprising: positioning a first electrode member on one side of biological tissue, the first electrode member comprising a flat plate-shaped electrode member defining a first electrode surface possessing an electrode surface area; providing a second electrode member comprising a pair of needle-shaped electrode members defining a second electrode surface possessing an electrode surface area that is different from the electrode surface area of the first electrode surface; sticking an opposite side of biological tissue with the pair of needle-shaped electrode members; and supplying electric energy between the first electrode surface and the second electrode surface while the biological tissue is sandwiched between the first electrode surface and the second electrode surface to fuse the biological tissue; wherein the first electrode includes a coated portion that is coated with an electrical insulation member and an exposed portion that is not coated with an electrical insulation member, the exposed portion defining the entire conductive electrode surface (S 1 ) of the first electrode member; wherein the needle-shaped electrode members defining the entire conductive electrode surface (S 2 ) of the second electrode member; and wherein a ratio (S 1 /S 2 ) between the entire conductive electrode surface area (S 1 ) of the first electrode member and the entire conductive electrode surface area (S 2 ) of the second electrode member comprising the pair of needle-shaped electrode members is more than 0.6 and less than 1.0.