Blood perfusion design

This design solution aims to use photoplethysmography (PPG) to measure the blood perfusion at the skin-mask interface. This design will utilize photodiodes, infrared LEDs and red or green LEDs will be used to measure this blood flow. Using these LEDs and pressure sensors, this design would determine if the skin is becoming ischemic.

A microcontroller would be used to collect the output signals from the photodiode and processed in order to trigger the alarm system when necessary. This alarm system would go off when pressure becomes too high or a decrease in blood flow is seen persistently over 10 minutes.

Following below are the design matrices for the different components of this design solution. Highlighted in green are qualities that the team considered good for the design. Highlighted in yellow are qualities that are not ideal but still useable. Highlighted in red are qualities that make the component not feasible. The chosen parts have been ordered to test the feasability of this design.

For the Microcontrollers, the team is between using the Elegoo Uno R3 and the SparkFun RedBoard Turbo.

For the colored LEDs, the team will most likely use the first Chanzon light.

For the infrared LED, the team will use the Chanzon light.

The team chose to use the ThorLabs FDS100-Si Photodiode.

The team will use the tactilus free form round pressure sensor.

This design solution was eliminated as of March 2, 2021 because of the inability to accurately measure blood perfusion.