Communicating with an Implanted Wireless Sensor
First Claim
1. A method for determining a resonant frequency of a wireless sensor, comprising:
- providing a calibration cycle, wherein the calibration cycle includes;
generating an energizing signal;
receiving a calibration signal; and
comparing the energizing signal and the calibration signal to determine a phase difference; and
providing a measurement cycle, wherein the measurement cycle includes;
energizing the wireless sensor;
receiving a sensor signal from the wireless sensor;
comparing the sensor signal and a reference signal to determine a second phase difference; and
using the second phase difference to determine the resonant frequency of the wireless sensor.
5 Assignments
0 Petitions
Accused Products
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.
-
Citations
20 Claims
-
1. A method for determining a resonant frequency of a wireless sensor, comprising:
-
providing a calibration cycle, wherein the calibration cycle includes;
generating an energizing signal;
receiving a calibration signal; and
comparing the energizing signal and the calibration signal to determine a phase difference; and
providing a measurement cycle, wherein the measurement cycle includes;
energizing the wireless sensor;
receiving a sensor signal from the wireless sensor;
comparing the sensor signal and a reference signal to determine a second phase difference; and
using the second phase difference to determine the resonant frequency of the wireless sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A method for determining a resonant frequency of a wireless sensor, comprising:
-
providing a calibration cycle for determining a first relationship between an energizing signal and a calibration signal; and
providing a measurement cycle for receiving a sensor signal, determining a second relationship between the sensor signal and the calibration signal and determining the resonant frequency of the wireless sensor based on the first relationship and the second relationship. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A method for determining a resonant frequency of a wireless sensor, comprising:
-
providing a calibration cycle, wherein the calibration cycle includes;
generating an energizing signal;
receiving a calibration signal; and
comparing the energizing signal and the calibration signal to determine a phase difference; and
providing a measurement cycle, wherein the measurement cycle includes;
energizing the wireless sensor;
receiving a sensor signal from the wireless sensor;
determining a characteristic of the sensor signal; and
using the characteristic to determine the resonant frequency of the wireless sensor. - View Dependent Claims (19, 20)
-
Specification