Diastolic Pressure- and Heart Rate-Dependent Modulation of Arterial Wave Reflection in a Biophysical Cardiovascular Model

Arterial pressure waveforms are shaped by vascular biomechanics and wave reflection, processes that become increasingly relevant in hypertension and vascular aging. This study aimed to investigate how heart rate (pump frequency) and baseline diastolic pressure modulate pressure waveform morphology and wave reflection in a controlled biophysical cardiovascular model. A biophysical model mimicking the aorta and its major branches was equipped with custom pressure sensors, enabling simultaneous recordings at multiple locations along the system. Measurements were performed at diastolic pressures of 60, 80, 100, and 120 mmHg and pump frequencies ranging from 24 to 120 bpm. The downstream tube length and reflection site configuration were systematically varied to evaluate the effects of distal boundary conditions. Increasing pump frequency resulted in higher pressure amplitudes and a steeper systolic upstroke (increased dp/dt). At higher frequencies and longer reflection pathways, forward and reflected wave components became more clearly separated, whereas branched distal networks produced complex multi-reflection patterns. Wave reflection in this experimental system is strongly dependent on heart rate, diastolic pressure, and distal tube configuration, providing mechanical insight into central pressure augmentation in hypertensive and aging-related conditions.