Pulse & Heart
Pulse sensors work by shining a tiny light into your skin to see how much blood is flowing underneath, a technique called photoplethysmography (PPG). Every time your heart beats, it pushes a fresh wave of blood through your veins, making them swell just a tiny bit. Because blood absorbs light, the sensor will see less light bouncing back at it during that exact moment of the heartbeat. By constantly watching for these rhythmic changes in the light, the sensor can count how many times your heart beats per minute and turn that pattern into a readable output.
