This ultra-compact electrocardiogram device was made using an ARM training/development unit –
It is a STM32 Primer with two copper foils placed on each side of the front circle. These two metal foils are the ECG electrodes. User can place his/her both thumbs on the copper foil to start the operation. The ECG trace is scrolling on the LCD display. The heart rate calculated and display on the top of the LCD display while the LED and beep sound indicating the pulse detected.
This is small enough to be wearable. Many medical and art uses come to mind. –Link
HOW TO – Build your own heart monitoring device, a simple ECG –Link
From the pages of MAKE:
DIY ECGs – MAKE:11 p.158 –Link