uDoc began as an effort to build a cheap, reliable, open source patient monitor for use in intensive care units in Ukrainian hospitals - where, at the beginning of the COVID-19 pandemic, most ICUs had one patient monitor. Faced with this, we built the uDoc prototype in under a month.

The basic concept is a single-board computer, such as Raspberry Pi, a screen, a USB base station (the same one we use in all our projects), and mouse and keyboard to interact with it. Ultimately we used Odroid C2 for the prototype as it had better specs. The finished device would measure various biometric data, including respiration and O2 levels, but initially we focused on ECG and SpO2 - to use uDoc with our uECG and uOxy devices.

The first prototype worked - first with ECG, then SpO2 - and could support either two uECGs, or a uECG and uOxy simultaneously, and could switch between modes.