Abstract: An electrosurgical handpiece applies electrical energy to a blade electrode to accomplish blade electrosurgery or to a transfer electrode in a nozzle to transfer electrical energy in arcs in a flowing gas to accomplish conductive gas electrocoagulation. The blade electrode may be selectively extended to conduct blade electrosurgery and withdrawn when conductive gas electrocoagulation is accomplished. Finger activated switches on the handpiece control the application of electrical energy to the blade electrode and the application of gas to the nozzle and the electrical energy to the transfer electrode within the nozzle. A cord includes a tubing for supplying gas to the handpiece. The cord also includes a plurality of conductors for conducting electrical energy to the two electrodes and conducting control signals to an electrosurgical apparatus which delivers the electrical energy and the gas. A nozzle and electrode assembly fits within the end of the tubing.

Abstract: An ultrasonic generating system for coupling vibrating energy into a load, such as living tissue, has been described which employs a piezoelectric crystal having excitation electrodes on opposite faces thereof. A feedback electrode is disposed on one face of the crystal adjacent to and insulated from one of the excitation electrodes to provide a feedback signal between the feedback electrode and the other excitation electrode. A power supply is provided for applying excitation energy to the excitation electrodes. The feedback signal is utilized to slave the frequency of the power supply voltage to the resonant frequency of the crystal and to disable the power supply when the impedance of the load applied to the crystal rises above a predetermined level.

Abstract: An electrical apparatus housing assembly unit is constructed from mounting columns, a top and bottom panel member and two side panel members. The mounting columns serve as structural components of the electrical housing assembly unit and also as members to which electrical components and the like may be removably mounted. Additional component parts such as facias and spacers may also be mounted to the mounting columns. The facias and spacers, in addition to aesthetic value, provide additional strength to the electrical apparatus housing assembly.

Abstract: A recessed handle assembly adapted for use in cases, panels and more particularly in electrical housing assembly units is disclosed. An aperture is provided in a wall of an electrical housing assembly unit. Into the aperture is placed a handle member which is preferably U shaped and is equipped with a pair of flanges. The flanges engage the exterior surface of the panel. A keeper member which also has a pair of flanges is mounted between the panel and the handle member. The keeper member is of such dimensions that it tightly fits between the panel and the handle member while the flanges of the keeper member engage the interior surface of the panel. The whole assembly is held together by a spring force which results from tight fit of the keeper member between the panel and the handle member. The handle assembly of this invention can be mounted into a panel in a very short time without the use of tools or mechanical skills.

Abstract: There is disclosed an isolation amplifier having an input amplifier, an output amplifier, a transformer having primary and secondary windings, an alternator connected to the secondary winding of the transformer for alternately presenting a voltage and a high impedance to the secondary winding, a first switching device connected between the primary winding of the transformer and the output of the input amplifier for connecting the output of the input amplifier to the primary winding when the alternator presents a high impedance to the secondary winding and for disconnecting the output of the input amplifier from the primary winding when the alternator presents a voltage to the secondary winding and a second switching device connected between the secondary winding and the input to the output amplifier therefore connecting the input of the output amplifier to the secondary winding when the alternator presents a high impedance to the secondary winding and disconnecting the input of the output amplifier from the s

Abstract: A disposable electrosurgical unit for generating electrical signals intended for applications to the body of a patient via an electrosurgical electrode is provided. Cutting signals and coagulation signals can be applied by the actuation of a switch in the handle supporting a removable blade electrode. The electrode blade has a mounting end configuration that can be removably mounted in a receptacle portion of a resilient conductive member. The conductive member is biased by its particular bowed shape and mounting configuration away from wire wrap contacts connected to a power generator source. The switching member is mounted in the electrode handle for selectively moving one of the bowed portions of the resilient conductive member into contact with a wire wrap contact for actuation of the electrode blade in a desired operative mode.

Abstract: A printed circuit board retainer for use in a rack or the like is provided comprising a housing member having an elongated slot adapted to receive a printed circuit board. A series of cam ramps are provided within the interior of the housing member. Mounted within the housing member is an elongated cam member adapted to move relative to the cam ramp of the housing member. The cam member has a plurality of follower ramps that are designed to bear against the cam ramps of the housing member. A lever member is pivotally mounted at one end of the housing member for actuating the cam member. The cam member as a result of the coaction of the follower and cam ramps is capable of exerting a retaining force in a direction traverse to the face of the printed circuit board.

Abstract: A high frequency signal for cutting human tissue is generated by common-emitter configured oscillator circuit that is adapted to maintain the cutting signal relatively constant in spite of impedance variations in the load caused by variations in the conduction of the tissue being cut.

Abstract: There is disclosed a circuit arrangement of a bipolar device connected in a circuit arrangement with unidirectional conducting devices connected between the input terminals of a differential amplifier for biasing purposes and a simplified electromagnetically coupled signal conditioning circuit and power supply and switching circuit combination whereby common mode, isolation and overload problems are avoided and the lack of input overload indication is overcome.