As Peter Balch explains, COVID-19 can sometimes give rise to cardiac complications. So, while not presented as an actual piece of medical equipment, he decided to construct an ECG (electrocardiogram) unit using an Arduino Nano for control along with an integrated 320×240 SPI display.
His battery-operated device features an AD8232 heart rate monitor module to acquire data from the human subject. This is connected to its wearer via electrode pads, or to a fake pulse generated by the Arduino for testing. The system allows you to view one or two heartbeats on its screen in a large format as well as many heartbeats in a smaller setup. A Poincaré display mode is also available, which plots the time between heartbeats.
Code, additional information, and future plans can be found in Balch’s project write-up.