Abstract: An apparatus is provided to detect electrical contact between anatomical tissue and a shield conductor: a transformer; an alternating current (AC) reference frequency signal generator to inject a reference frequency signal to a primary winding of the transformer; a reactive impedance coupled in parallel with a secondary winding of the transformer between a first node and a second node; and a phase match detector circuit to detect a phase match between the reference frequency signal and a reflected reference frequency signal that is reflected from the secondary winding to the primary winding.

Abstract: Implementations relate to hand presence sensing at a control input device. In some implementations, a control input device includes a base member, a handle coupled to the base member and configured to be manually contacted at a grip portion of the handle and moved by a hand of a user in one or more degrees of freedom, one or more control input sensors configured to detect positions or orientations of the handle in the one or more degrees of freedom, and a presence sensor coupled to the base member. The presence sensor has a sensing field, and at least a portion of the sensing field is located proximate to the handle.

Abstract: An apparatus is provided to detect electrical contact between anatomical tissue and a shield conductor: a transformer; an alternating current (AC) reference frequency signal generator to inject a reference frequency signal to a primary winding of the transformer; a reactive impedance coupled in parallel with a secondary winding of the transformer between a first node and a second node; and a phase match detector circuit to detect a phase match between the reference frequency signal and a reflected reference frequency signal that is reflected from the secondary winding to the primary winding.

Abstract: A method is provided to seal and cut biological tissue. An alternating current (AC) scaling signal is imparted between a set of sealing electrodes. An AC cutting signal is imparted between a set of cutting electrodes in response to a biological tissue impedance between the sealing electrodes reaching a first impedance threshold value. The AC scaling signal is halted at an end of a time interval, beginning while the AC cutting signal is imparted between the cutting electrodes, in response to impedance of the biological tissue disposed between the set of sealing electrodes reaching a second impedance threshold value.

Abstract: A surgical instrument includes a shaft that includes an elongated tube having distal and proximal end portions. The tube houses an electrical conductor that includes distal and portions and that extends between the proximal and distal end portions of the elongated tube. An end effector at the distal end portion of the elongated tube includes an electrode electrically coupled to the distal portion of the electrical conductor. A switch at the proximal end portion of the shaft is operatively disposed between the distal and proximal portions of the electrical conductor that is configured to electrically couple and decouple the distal and proximal portions of the electrical conductor.