A time domain reflectometer impedance sensor in an implantable cardiac stimulator.

摘要

The time domain reflectometry (TDR) impedance sensor measures body impedance along a lead or catheter implanted in a patient's cardiovascular system. The TDR sensor applies an electrical stimulus to the lead and measures reflections echoed from impedance variations along and distal to the lead, which are superimposed on the applied stimulus. The measured signals may be analyzed with respect to time-of-flight and distance along the lead to detect a number of physiologically meaningful signals.