Pulse Transit Time Estimation for Blood Pressure Measurement in Patients Implanted with a Left Ventricular Assist Device.

Due to an ageing population, cardiac issues such has heart failures occur more and more frequently. As the number of donors' heart stagnates while more and more people are in need of a heart transplant, a growing number of patients are implanted with a left ventricular assist device (LVAD). However, these patients are still at risk and their condition needs to be monitored. Monitoring of patients implanted with an LVAD requires continuous blood pressure (BP) measurements, which are unfortunately difficult for these patients if using the existing methods. This paper examines the applicability of pulse transit time (PTT) based BP measurement in LVAD implanted patients, specifically when using a pair of uncalibrated pressure sensors. Taking into account the specificities of LVADs and LVAD implanted patients, we present a model of the multichannel signals that can be recorded by such system. We use a small dataset of signal recorded with a simulator of the cardiovascular system of an LVAD implanted patient to conduct a preliminary study. The initial results presented in this paper provide useful hindsights and lays the groundwork for a study in a more realistic setting.