2024
Tezis
The pulse arrival time (PAT), defined as the time difference between the R-peak of an electrocardiogram (ECG) and the onset of an increase in blood pressure at the periphery, is a useful tool for assessing the functional state of the cardiovascular system. PAT depends on many factors such as the structure of the vessels network, vessel diameter, wall stiffness, blood pressure, heart rate, etc. Either pressure or optical sensors are used for clinical assessment of PAT. In recent years, there has been a significant increase in interest to developing devices for cuffless estimation of blood pressure (BP) based on a photoplethysmography (PPG) and ECG techniques, which measure PAT to use it as a surrogate for BP. The PPG signal in these systems is recorded directly from the patient's skin using a contact sensor affixed on distal part of the body (fingertip, forearm, earlobe, etc.), which can cause discomfort. In addition, any contact-type sensor affects the blood flow in the contact area, which is often not evaluated and not taken into account, despite the well-known fact that any skin contact may affect cutaneous microcirculation. The aim of our work was to study how stable PAT is with changes in microvascular blood flow parameters, caused by the controlled local hyperemia.