High frequency power measurement
US5422567A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 27, 1993 |
| Grant date | Jun 6, 1995 |
| Priority date | — |
| Expiry date | Dec 27, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R21/133
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A monitoring circuit for an electrosurgical generator has active and return output conductors. Voltage, current and the inverse of current picked up inductively are provided to a adder circuits for summing the picked up voltage and current and computing the difference of the picked up voltage and the current. Root mean square to direct current converters signal RMS average values of the sum and difference. A microprocessor squares the values and applies them to a formula wherein the sum signals have subtracted therefrom the difference signals; the results are divided by four to provide the root mean square of the power applied to the load. During desiccation the output is regulated in response to impedance to shut off output. A diagnostic circuit relates impedance load and output response during operation to a look up table or a microprocessor algorithm to calibrate. Feedback modifies the output when the adders determine the power applied to the load in real time. A method has generator output to active and return conductors and to inductive pick ups for voltage and current, computes sum and differential values, changes root mean square to direct currents, squares the values and su…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.