Medical device

摘要

A medical device comprising: an end effector 9 for gripping tissue; an ultrasonic transducer 8; a drive circuit 29 generating a periodic signal and a controller to apply the signal to either the transducer or the effector. The drive circuit may have first and second resonant circuits having different first and second resonant frequencies. The device may comprise: a signal generator supplying the resonant circuits with a cyclically varying voltage; one or more batteries comprising an active fuse circuit; a waveguide. The controller may: vary the period of the signal about the first or second resonant frequency adjusting the energy delivered to the tissue; may vary the signal to track changes in resonant characteristics. A medical device comprising: a tissue gripping effector; a drive circuit generating a varying signal driving energy into the tissue; a controller responsive to a sensing circuit where the drive circuit comprises an impedance element coupled to a reference where the sensing circuit comprises a divider circuit and a bias signal generator. A medical device comprising: an effector; one or more batteries with an active fuse; a signal generator; a controller may further comprise: an active fuse circuit comprising a switch to disconnect the signal generator.