Constant output electrosurgical unit
First Claim
1. An electrosurgical unit providing an output voltage to a load, comprising an oscillator producing an output signal of a given frequency, a control circuit means coupled to the oscillator for providing an output voltage from the oscillator for use in surgical procedures, a feedback circuit means coupled from the output to the input of the oscillator to maintain the output voltage level from the unit as a substantially constant value independent of the load, and wherein said oscillator includes a control electrode, and said control circuit means includes a switching transistor having its collector-emitter circuit connected between said control electrode and ground, and having a fixed voltage on its base, capacitor means, and means for selectively connecting said means to said base.
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Accused Products
Abstract
An electrosurgical unit which provides a voltage output to a load. An oscator in the unit produces the output of a given frequency. A switching circuit coupled to the oscillator provides an unmodulated RF carrier from the oscillator for use in cutting procedures and a pulse modulated RF voltage from the oscillator for use in coagulation procedures. A feedback circuit is coupled from the output to the input of the oscillator to maintain the output voltage level from the unit at a substantially constant value independent of the load.
472 Citations
17 Claims
- 1. An electrosurgical unit providing an output voltage to a load, comprising an oscillator producing an output signal of a given frequency, a control circuit means coupled to the oscillator for providing an output voltage from the oscillator for use in surgical procedures, a feedback circuit means coupled from the output to the input of the oscillator to maintain the output voltage level from the unit as a substantially constant value independent of the load, and wherein said oscillator includes a control electrode, and said control circuit means includes a switching transistor having its collector-emitter circuit connected between said control electrode and ground, and having a fixed voltage on its base, capacitor means, and means for selectively connecting said means to said base.
Specification