This part will take a deep dive on the methods to perform the measurement of these pulses. Pulse Sampling Theory Sensors based on Pulse Counting Theory (discussed in Part 2 of the series) convert the ...

These photoplethysmographic sensors operate by shining light into someone’s flesh – usually a finger or ear lobe – and recording the light reflected back to the source.

Garmin has been making serious strides to provide more details on sleep quality and this latest activity tracker includes four sleep stages along with blood oxygen saturation gauging.