William Alexander Bowers
Podiatry at Haddon Rd, Denver, CO

4438766, Mar 27, 1984

Sep 3, 1981

6/299204

William J. Bowers - Aurora CO

C. R. Bard, Inc. - Murray Hill NJ

A61B 1739

12830314

A solid-state electrosurgical generator is disclosed which provides three separate output circuits that may be operated from a single common power source. One of the output circuits produces an output electrical waveform which is optimized for cutting and coagulation with monopolar electrodes. Another circuit provides a waveform which is optimized for cutting and coagulation with bipolar electrodes. The other electrosurgical circuit produces an output electrical waveform which is optimized for fulguration. The output circuits produce the optimized waveforms by appropriately processing electrical power provided by a D. C. power source. In order to do this, the output circuits may be connected to the power source by means of four semiconductor switches may be arranged in either a bridge configuration for one output circuit or in a series arrangement for the other output circuit. The switches are, in turn, controlled by a timing circuit which provides different timing waveforms to the switches depending on their configuration.

4559943, Dec 24, 1985

Nov 2, 1983

6/547964

William J. Bowers - Aurora CO

C. R. Bard, Inc. - Murray Hill NJ

A61B 1739

12830314

A solid-state electrosurgical generator is disclosed which provides three separate output circuits that may be operated from a single common power source. One of the output circuits produces an output electrical waveform which is optimized for cutting and coagulation with monopolar electrodes. Another source provides a waveform which is optimized for cutting and coagulation with bipolar electrodes. The other electrosurgical source produces an output electrical waveform which is optimized for fulguration. The output circuits produce the optimized waveforms by appropriately processing electrical power provided by a D. C. power source. In order to do this, the output circuits may be connected to the power source by means of four semiconductor switches which may be arranged in either a bridge configuration for one output circuit or in a series arrangement for the other output circuit. The switches are, in turn, controlled by a timing circuit which provides different timing waveforms to the switches depending on their configuration.

4727874, Mar 1, 1988

Sep 10, 1984

6/649261

William J. Bowers - Aurora CO
Phillip D. Hardwick - Aurora CO

C. R. Bard, Inc. - Murray Hill NJ

A61B 1739

12830313

A pulse width modulation technique regulates the output power of each cycle of a radio frequency surgical signal of an electrosurgical generator. The delivered power of the surgical signal is determined by multiplying the sensed current and the sensed voltage of the surgical signal. An error signal is established by the difference of the actual delivered power with respect to a selected desired output power. The error signal is operatively utilized to modulate the pulse width of each driving pulse which creates the cycles of the surgical signal. Limits on the sensed voltage and sensed current signals are established to limit the output characteristics of the surgical signal. A minimum current limit signal is utilized to limit the maximum output voltage into relatively high impedances. A minimum voltage limit signal is utilized to limit the maximum output current into relatively low impedances. Very rapid response times and very effective power regulation even into relatively high impedance tissues are possible with the pulse width modulation technique.