Communicating with an implanted wireless sensor
US7839153B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 2009 |
| Grant date | Nov 23, 2010 |
| Priority date | — |
| Expiry date | May 15, 2029 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2560/0223
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. The system energizes the sensor with a low duty cycle, gated burst of RF energy having a predetermined frequency or set of frequencies and a predetermined amplitude. The energizing signal is coupled to the sensor via magnetic coupling and induces a current in the sensor which oscillates at the resonant frequency of the sensor. The system receives the ring down response of the sensor via magnetic coupling and determines the resonant frequency of the sensor, which is used to calculate the measured physical parameter. The system uses a pair of phase locked loops to adjust the phase and the frequency of the energizing signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.