Combined magnetic field detector and activity detector employing a capacitive sensor, for a medical implant
US5709225A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1995 |
| Grant date | Jan 20, 1998 |
| Priority date | — |
| Expiry date | Sep 20, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S128/903
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A medical implant contains a magnetic field detector with a sensor whose capacitance changes in the presence of a magnetic field with a predefined strength, and a capacitance-controlled unit connected to the sensor. The capacitance-controlled unit sends a measurement signal to a detection unit. If a measurement signal parameter affected by capacitance exhibits a specific change over a predefined period of time, a detection signal is generated by the detection unit to indicate the presence of a magnetic field. The sensor's capacitance also changes when the sensor moves, and this is utilized for measuring activity in an activity measurement circuit connected to the capacitance-controlled unit and for generating an activity signal on the basis of the measurement signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.