Cardiac output monitoring by long time interval analysis of a radial arterial blood pressure waveform with correction for arterial compliance changes using pulse transit time

We previously developed a technique for estimating relative cardiac output (CO) change by long time interval analysis of a radial arterial blood pressure waveform. This technique analyzes the slow, beat-to-beat changes in the waveform to circumvent the confounding wave reflections but assumes constant arterial compliance (AC). Here, we sought to correct the CO estimates of the technique for potential AC changes using pulse transit time - a conveniently measured index of AC. For proof-of-concept, we compared the original and corrected techniques using invasive swine hemodynamic data. The corrected technique reduced the overall calibrated CO estimation error by 18% relative to the original technique.