IMPEDANZMESSUNG UND DEMODULATION ANHAND EINER IMPLANTIERBAREN VORRICHTUNG

摘要

An implantable medical device performs impedance measurement and demodulation, such as for obtaining lead impedance measurements, or thoracic impedance measurements, such as for extracting respiration, cardiac stroke, or fluid status information. A 4-point FIR filter demodulator can be used to demodulate a two-phase current excitation waveform. The demodulator can also be used to measure noise for triggering a noise response. Among other things, an increased excitation current level can be used when noise is deemed to be present.