Low-cost camera-based assessment of venous hemodynamics in the lower limbs: a study on young healthy volunteers

This paper presents a non-contact and cost-effective method to assess venous hemodynamics along the lower limbs using photoplethysmography imaging (PPGI). Seventeen healthy volunteers performed the venous muscle pump test, inducing venous blood volume changes in their lower legs, which were recorded using a webcam. PPGI signals were extracted from three regions along the lower leg. Key parameters derived from a physiological model were evaluated and analyzed statistically: perfusion amplitude, ejection time constant, and peripheral venous flow index. The method demonstrated robust estimation of physiologically explainable parameters, and the potential to improve venous function diagnostics with high spatial resolution.