Raspberry Pi PPG

In this project I tested if I could measure PPG with a Raspberry Pi 4 (Model B) based system.
The working principle is that a red led is used as the light source, and a light transistor
measures the amount of light transmitted trough the finger. Raspberry Pi has only digital data
pins, and that is why a MCP3008 analog to digital converter is used for digitalizing the voltages
from the phototransistor. The measurement and analysis programs were implemented in Python.

The data is filtered and a naive peak detection is implemeted. The heart rate can be calculated
with the system. Currently no amplifier is used to enhance the signal. Also a some sort of concealed
clip has to be implemented to reduce the amount of ambient light hitting the phototransistor.