Quantity   Component name
1 × Adafruit Feather 32u4 https://www.adafruit.com/product/2771
1 × Pulse Sensor https://www.adafruit.com/product/1093
1 × 3D printed Casing Made of one of the next materials
1 × NinjaFlex Filament If you plan to implement the sensor on the socket of the prostesis or make a band to hold it.
1 × Battery Lithium Ion Battery Pack - 3.7v 4400mAh of Adafruit https://www.adafruit.com/product/354