Pulse oximeters, a type of photoplethysmography (PPG) sensor, are electronic devices that measure a person’s blood-oxygen saturation (SpO 2) and heart-rate (HR) levels. Since their inception in the ...

One of the first frustrating situations a beginning microcontroller programmer will come across is the issue of debouncing switches. Microcontrollers are faster than switches, and the switch has yet ...

Despite its widespread use, PPG accuracy can vary significantly across individuals, particularly by skin tone. Darker skin contains more melanin, which absorbs and scatters light, often leading to ...

Part 1 of this series provided an overview on using reflectometry for a pulse plethysmograph (PPG) waveform and described the physical and physiological principles at work. Much attention has been ...