Patent ID: 8706208

Claim:
A passive wireless gastroesophageal sensor comprising: an LC (inductor capacitor) resonance circuit; one or more electrodes configured to measure an impedance within a gastroesophageal tract; and a passive batteryless Radio Frequency Identification (RFID) circuit connected to the LC resonance circuit and the one or more electrodes, wherein the passive batteryless RFID circuit comprises a voltage regulator, a voltage multiplier connected to the voltage regulator, a transistor switch connected in parallel between the LC resonance circuit and the voltage multiplier, and an impedance to frequency converter connected to the electrodes and the voltage regulator, wherein the impedance to frequency converter controls the transistor switch, and wherein the switching frequency of the transistor switch varies with the measured impedance such that the RFID circuit transmits a frequency modulated signal using the LC resonance circuit, the frequency modulation of the transmitted signal varying between a first frequency corresponding to a non-reflux condition and a second frequency corresponding to a reflux condition, based on the measured impedance, in response to a signal received from a detector; and wherein the sensor is adapted to be attached to the gastroesophageal tract.