Photoplethysmographic Detection of LDR and Photodiode in Varying Distance of Light Source to Area

Abstract:

Light source and light detector are the two most considered components in photoplethysmography to be able to obtain a signal conforming to specific information one needs. The distance of the light source to the measured area is vital in order to acquire the best possible signal. The distance of the source to the area was varied from 1 cm to 3 cm to 5 cm. The aim of the study is to establish the effective possible distance of the light source to the measured area that would provide best detection response in the dorsal skin of human subjects. This study utilized three light emitting diodes as sources; while, light dependent resistor and photodiode were used as light detectors or sensors. The testing was comprised of two parts. The first utilized a light dependent resistor as the photodetector; while the second used a photodiode. The series of tests performed substantiated that yellow LED, at a distance of 3 cm away from the area to be measured, was the best LED to be used for dorsal skin measurement. Photodiode was also a better sensor than the LDR.

Año de publicación:

2020

Keywords:

• Photodiode
• LDR
• optical response
• photoplethysmography

Fuente:

scopus