Study of protective films for optical reflection systems with LEDs and photodiodes

Photoplethysmography devices use an optical system to extract informationfrom blood. The human body in direct contact with the system generates layers of oiland/or particles that significantly interfere with optical reading. To avoid this, it isnecessary to use a protective film and a cleaning method. The objective of this studyis to experimentally study the optical characteristics of six types of films made fromdifferent plastic materials that could be used as a protective film in a pulsephotoplethysmography system and, based on these results, define the material thatbest suits the system.