Detection of electrode/patient motion and fast restore limits
US5247939A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 1992 |
| Grant date | Sep 28, 1993 |
| Priority date | — |
| Expiry date | Jan 10, 2012 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61N1/3931
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A defibrillator/monitor (10) employing a motion detection circuit 18 and control and processing circuit (20) that cooperatively detect motion at a patient-electrode interface. In that regard, an impedance measurement circuit (24) produces an output indicative of the impedance of the interface. This output is then processed by a number of filter elements before being analyzed by a motion detection routine (52). The motion detection routine includes subroutines (62 and 64) that compare the impedance against distinct upper and lower limits and then monitor the time at which the signal is above and below the limits. Basically, motion is indicated if the signal undergoes relatively large variations for a short time, or smaller variations for a longer time. A third motion clear subroutine (66) is used to determine when motion is no longer detected. Finally, a similar scheme (102) is employed to quickly restore the various filter elements after saturation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.