Method for detecting blade breakage using rate and/or impedance information
US6633234B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 2001 |
| Grant date | Oct 14, 2003 |
| Priority date | — |
| Expiry date | Oct 16, 2021 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2017/320089
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Failures associate with bad hand pieces and blade failures in an ultrasonic surgical system are distinguished by monitoring the rate of change of the resonance frequency and the rate of change of the resonance impedance of the hand piece/blade as the drive frequency is changed. As the system reaches resonance, the control system locks onto the resonance frequency. When a loss of lock occurs with no recovery, the rate of change of the frequency and rate of change of the impedance are compared to obtain the fastest rate of change which is stored in non-volatile memory of the ultrasonic generator. If the rates of change are higher than normal rates of change due to temperature changes with the longest blades, a “Bad Blade” message is displayed on an LCD.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.