A digital instrument for venous muscle pump test

Design and development of a prototype unit to measure venous refilling time (VRT) and muscle pump capacity (MPC) during a venous muscle pump test (VMPT) is presented here. Instead of normalizing the photo-plethysmo-graph (PPG), as is common in the VMPT instruments in vogue, a suitable signal processing technique that extracts a signal proportional only to the blood volume changes underneath the PPG sensor is employed. Apart from the measurement of VRT and MPC, the prototype unit also provides a measure on the pulse rate.