Impact of Bilateral Thigh Occlusion on the Remote Photoplethysmography Signal Recorded from the Palm

Occlusion in limbs, arising from conditions like peripheral arterial disease or certain postures, significantly affects blood flow and vascular health. Our study examined the impact of bilateral thigh occlusion on systemic and local hemodynamics using remote photoplethysmography (PPG) waveform in 18 healthy subjects. By employing a supra-systolic occlusion protocol, we assessed changes in heart rate (HR), mean arterial pressure (MAP), and total peripheral resistance (TPR), along with PPG signal alterations at 540 nm. Results showed that occlusion led to temporary fluctuations in MAP, HR, and TPR, followed by notable increases in these parameters and the PPG waveform parameter RI. Post-occlusion, we observed substantial declines in MAP, TPR, and RI. These findings underline the significance of thigh occlusion in altering systemic hemodynamics and suggest the potential of palmar PPG in evaluating vascular resistance. However, the complex relationship between central hemodynamics and local cutaneous microcirculation responses, influencing the PPG signal, require further research.