Abstract: An electrosurgical system includes an electrode assembly which is detachably combined with an aspiration/irrigation cannula. The electrode assembly includes a shaft having an electrode tip at its distal end and a connector plug at its proximal end. A sleeve slidably and rotatably received on the proximal end of the shaft includes connecting means for securing to a proximal housing on the cannula. The system includes both the cannula and electrode assembly and is useful in performing electrosurgical procedures as part of minimally invasive surgical operations. A non-conductive cannula and valve housing are also provided which prevent capacitive coupling between the cannula and a monopole electrode.

Abstract: A bi-directional flow valve for use in regulating flow of pressurized fluids in surgical instruments is disclosed. The valve comprises a valve body having an axial bore of variable radius, a plunger axially and slidably mounted within the bore of the valve body, a flange provided on the plunger for circumferentially engaging the bore at its narrowest point, a spring means for urging the flange against the bore at its narrowest point, and seal means to seal the gap between the plunger and the bore, and displacement means to move the plunger and flange out of contact with the bore so that fluid may pass through the bore and thus through the valve.