Determination of vascular input impedance in near real-time using a portable microcomputer
A method for determining vascular input impedance using a portable laptop computer coupled to more conventional laboratory measurement equipment is described. The major impediment overcome in the clinical implementation of this microcomputer-based system was the rapid Fourier transformation of pulsatile pressure and flow waveforms from time domain to frequency domain. To meet this need, software was written to allow gating of data collection and Fourier analysis in a continually repetitive, alternating manner in synchrony with the cardiac cycle. High computational speed was achieved by using a math coprocessor and limiting the Fourier analysis to hemodynamically important harmonics of heart rate.