Real-time DSP-based conductance catheter measurement system for estimating ventricular volumes

Conductance catheter is a tool for estimating real-time ventricular volume by measuring time-varying ventricular admittance, provided that myocardial contribution can be determined and then removed. One approach for determining the myocardial contribution is to measure both the magnitude and phase of the ventricular admittance rather than only its magnitude. However, the sensed signal waveform of the conductance catheter system is very special; thus, a deliberately designed admittance measurement system is developed for this application. A novel real-time DSP-based conductance catheter measurement system was designed to measure time-varying ventricular admittance signals, including both the magnitude and the phase. With some signal-processing techniques, the system achieves a high degree of accuracy and high resolution with a relatively low sampling rate.