Monopolar electrosurgical instruments.

摘要

A monopolar electrosurgical instrument 60, 72 for utilization with endoscopic and laparoscopic surgical procedures. The instrument is structured so as to substantially eliminate the adverse effects occasioned by capacitive coupling between the instrument and tissue adjacent thereto within the body being operated upon. Capacitive coupling is controlled through the implementation of the shaft structure 10 itself with an electrically insulative polymeric material 4 of low dielectric constant which is combined with a current conductor 12 centrally disposed therein which is of minimum diamter effective to carry requisite current to a working tip. A shield arrangement may be provided such as a coextruded electrically conductive wire mesh 472 surmounting the internally disposed electrical conductor. This shield, in one embodiment, may be coupled with return ground employing electrical connectors which assure proper coupling with source and ground. <IMAGE>