Patent ID: 7113816

Claim:
An ultra-miniature in-vivo electrode used for measuring the bioelectrical neural activity, comprising: a core body, and a cylindrical clad body surrounding the core body, wherein the core body and the cylindrical clad body have (1) a center, (2) a through-hole in each center of said core body and said cylindrical clad body said through-hole being aligned in a straight line to lead a measuring objects thru each center of said core body and said cylindrical clad body, and (3) a slit reaching the surface of said core body and said cylindrical clad body from said through-hole, wherein the core body comprises a pair of cylindrical conductors, an intervening member inserted between the conductors, an edge member covering each side ends of each conductor, and a pair of wires connected to each said conductor, penetrating said cylindrical clad body to its outside where a surface of said wires are insulated, wherein the conductors, the intervening member, and the edge members have the same diameter, and wherein the clad body, the intervening member, and the edge member are made of insulating material.