Patent ID: 8412317
Filing Date: 2013-04-02
Classification: A61B

Abstract:
1. A device for measuring an impedance of a tissue of a patient, the device comprising: calibration circuitry comprising an impedance; at least four electrodes configured to couple to the tissue of the patient, the at least four electrodes comprising at least two measurement electrodes and at least two drive electrodes; drive circuitry coupled to the at least two drive electrodes and the calibration circuitry to pass a current through the tissue and the calibration circuitry simultaneously, the drive circuitry configured to increase the current from a first current amount at a first frequency to a second current amount at a second frequency, the second frequency greater than the first frequency; measurement circuitry configured to couple to the at least two measurement electrodes and the calibration circuitry, the measurement circuitry configured to measure a calibration signal from the calibration circuitry and a tissue impedance signal from the at least two measurement electrodes; and processor circuitry comprising a tangible medium configured to determine the impedance of the tissue in response to the calibration signal and the tissue impedance signal.