Method and apparatus to measure bioelectric impedance of patient tissue
US8903484B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 26, 2013 |
| Grant date | Dec 2, 2014 |
| Priority date | — |
| Expiry date | Mar 26, 2033 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2560/0223
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A device to measure tissue impedance comprises drive circuitry coupled to calibration circuitry, such that a calibration signal from the calibration circuitry corresponds to the current delivered through the tissue. Measurement circuitry can be coupled to measurement electrodes and the calibration circuitry, such that the tissue impedance can be determined in response to the measured calibration signal from the calibration circuitry and the measured tissue impedance signal from the measurement electrodes. Processor circuitry comprising a tangible medium can be configured to determine a complex tissue impedance in response to the calibration signal and the tissue impedance signal. The processor can be configured to select a frequency for the drive current, and the amount of drive current at increased frequencies may exceed a safety threshold for the drive current at lower frequencies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.