Mar 21, 2006 #1 F fireflies Newbie level 5 Joined Feb 1, 2006 Messages 8 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,350 photoplethysmography circuit This is the schematic I drew for the PPG Problems: 1) I cant seem to find the desired angle that our skin is able to reflect back the IR light. It seems that light from undesired places is absorbed too. 2) wondering if the resistor values is too large (noise) 3) circuit is partially working.
photoplethysmography circuit This is the schematic I drew for the PPG Problems: 1) I cant seem to find the desired angle that our skin is able to reflect back the IR light. It seems that light from undesired places is absorbed too. 2) wondering if the resistor values is too large (noise) 3) circuit is partially working.