Rem output stage topology
US5695494A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 22, 1994 |
| Grant date | Dec 9, 1997 |
| Priority date | — |
| Expiry date | Dec 22, 2014 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B18/16
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Apparatus monitors RF return current to maximize the AC signal of impedance at two return electrodes. A transformer with driving and driven windings isolates ESU and patient. At ends of the driving winding are signal and ground terminals joined to the return electrodes with capacitors returning current. An AC coupling capacitor at the signal terminal has a timing circuit in sync to the voltage wave and relative to impedance of the return electrodes. Microprocessing the voltage at the signal terminal of the driving winding watches impedance and determines if the RF return current path is adequate. Voltage detection within the timing circuit has a voltage shaping circuit. A voltage comparator after the voltage detection forms a square wave. A current detection circuit and a coupling capacitor allow AC flow to the driving winding. Current shaping circuit in the current detection circuit has a voltage comparator at the output to form a square wave. Phase detection at the voltage and current detection circuits outputs filters the phase difference that is sampled and held as DC input to a switch, with an output and a few inputs to DC voltages. Phase locking an oscillating voltage source …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.