Adapter assembly for use with a cranial biosensor

Claim 1

An adapter assembly for accurately positioning a removable biosensor, having a cylindrical body portion, in a stepped circular hole bored through the cranium, said hole having an upper portion and a lower portion, the upper portion of said hole having a larger diameter than and coaxial with the lower portion so as to form a radial bearing surface intermediate said upper and lower portions, said adapter assembly comprising: (a) a first tubular member adapted for insertion into said hole, said tubular member having an upper portion and a lower portion, the upper portion of which tubular member is formed as a radially outwardly extending flange adapted to the inside diameter of the upper portion of the hole, the lower portion of which tubular member formed as a plurality of downwardly depending spring-like legs adapted to the inside diameter of the lower portion of the hole, said legs having lower tips formed as outwardly extending cams; and (b) a second tubular member adapted for insertion into the first tubular member, said tubular member having an upper portion and a lower portion, the upper portion of which tubular member is formed as a radially outwardly extending flange adapted to the inside diameter of the upper portion of the first tubular member, the lower portion of which is adapted to the inside diameter of the lower portion of the first tubular member, the inside diameter of the second tubular member being slightly larger than the outside diameter of the cylindrical body portion of the biosensor such that said body portion is slidable therein, whereby when the second tubular member is inserted into and coaxially aligned with the first tubular member the spring-like legs are urged into contact with the cranial wall defined by the lower portion of the hole and the outwardly extending cams engage the lower outer periphery of the cranium defined by the lower portion of the hole.