Three of the four weeks I spent at Tech Camp were solely spent on building a foundation of skills such as soldering, reading circuit diagrams, and understanding circuit components.
This culminated in a final project, where we were given a circuit diagram and appropriate materials to build a pulse monitor.
I was provided a 3D-printed block of plastic with a hole that could fit a finger. Within that hole lied a light on one side and an infrared light sensor on the other. Blood absorbs different amounts of infrared light depending on how oxygenated it is, so a change in infrared light levels detected by the sensor translated to a blood pulse from the heart.
With a little coding, we could estimate the pulse rate of a patient and display the heartbeats per minute on an LCD display.