NON-INVASIVE METHOD AND APPARATUS FOR TISSUE DETECTION

摘要

An apparatus and method for non-invasively determining tissue structure by applying a periodic waveform to an external or internal body part. A microprocessor (16) provides instruction to a waveform generator (8) to generate a plurality of different periodic waveforms to at least one sampling electrode (12) electrically connected to at least on return electrode (14) through the tissue structure. The impedance of the tissue structures are selectively determined for each generated waveform. After determining a plurality of impedance measurements various calculations are performed, including determining a ratio of impedance change and the applied current change. The apparatus may apply the same waveform to all sampling electrodes (12) simultaneously, or apply the waveform to a few as one sampling electrode (12) at a time. The apparatus may also simultaneously apply a plurality of waveforms to a plurality of electrodes to maintain the same current waveform on each sampling electrode (12).