Arterial pulse wave analysis based on PPG and EMFi measurements

Photoplethysmography (PPG) is an optical measurement technique either in reflective or transmission mode over the skin. PPG amplitudes depend on light wavelength which is typically in near infrared region. Eletromechanical film (EMFi) is an excellent sensor material for low-current long-term applications, e.g., arterial pulse wave recordings. EMFi measures extremely very small movements of the arterial wall and the tissue around the artery on the skin whereas PPG measures very low light absorption, transmission, and scattering caused by oxihemoglobin. Both PPG and EMFi sense elastic wave recoil, impact, and reflection caused by left ventricular contraction. Each type of pulse waves can be analysed in different ways, but they are extensively synergetic. Analysis type (PSD, PDF, NPWD, SDPPG, SDEMFi) shows different information.