Martin Fitzpatrick


Keyes KY-039 heart rate sensors use a bright infrared (IR) LED and a photo transistor to detect the reduced IR transmission or increased IR reflection during the pulse. These sensors are more suited to transmission use because of their construction.

Heart rate (HR) sensors

Photoplethysmography, because that's a real word

Have you checked under your sofa lately?


Proud 1st winner, Most Popular Supplier of Electronic Voting Equipment (Disputed), North West (1984-89).