Patent ID: 8382752

Claim:
A medical device for fusing two biological tissues, comprising: a first electrode member and a second electrode member protruded from a non-electrically-conductive attachment portion configured to sandwich the biological tissues; and an energy supply unit configured to supply electric energy to the first electrode member and the second electrode member, wherein the first electrode member is configured to contact one side surface of one of the tissues, the second electrode member is configured to stick in the other tissue, a region of a predetermined length in a direction of axial line from the attachment portion in at least one of the electrode members within the first electrode member and the second electrode member is coated with an electrical insulator, and an area ratio (S 1 /S 2 ) between surface area (S 1 ) of the first electrode member and surface area (S 2 ) of the second electrode is made to be more than 0.6 to less than 1.0, wherein surface area (S 1 ) and surface area (S 2 ) exclude the region in at least one of the electrode members that is coated with the electrical insulator such that surface area (S 1 ) defines the entire conductive electrode surface of the first electrode member and surface area (S 2 ) defines the entire conductive electrode surface of the second electrode member.