Evaluation of Microcirculation With Photoplethysmography (Pulse Oximetry) in Healthy Volunteers and Ventilated Patients

An attempt is made to explore different physiological aspects that affect microcirculation such as vascular tone and blood volume. Photoplethysmography usually examines the AC wave equivalent to the pulsatile wave, however the DC component has been less explored and can account for the microcirculation and volemia status of the subjects. Since there is no gold standard, it will be compared against different validated methods.