Abstract: An ultrasonic surgical instrument which incorporates a thumb and finger ring-actuated structure for the ultrasonic clamping device which is finger-operated in a scissor-like mode. Provided is either a fixed or removable blade tip and clamp assembly for ultrasonic treatments, so as to impart to the surgical instrument the ability of providing a variety of essentially exchangeable tips while reducing operationally engendered vibrations and stresses at the point of the coupling thereof to the clamp arm. The assembly is actuatable by relative movements between a blade extender and an outer tubular sheath extending to a handle end connected to the thumb and finger ring-actuated structure.

Abstract: An ultrasonic clamp coagulator assembly embodying the principles of the present invention is configured to permit selective cutting, coagulation, and clamping of tissue during surgical procedures. In an ultrasonic blade according to the present invention, the blade is constructed such that the cross-sectional area of the blade is smaller at the proximal end of the compression zone than at the distal end. This performance-enhancing feature creates a more consistent cutting and coagulation of the tissue along the length of the blade reducing the time the blade is in operation and reducing overall heat generation.

Abstract: A linear power supply is preregulated to compensate for variations in load and power line voltage. The inductance on the primary side of the power supply step down transformer is varied by a current controlled inductor to efficiently maintain the desired power supply output voltage. A variable current is supplied to the inductor by a d.c. power source under control of an integrator which monitors output voltage fluctuations. In one embodiment of the invention, a voltage selector is included for use with power supplies which provide more than one output voltage. This selector automatically selects the most heavily loaded output voltage for control of the inductor.