Electrocardiography for Cheap: DIY ECG Uses One LM741 Op-Amp, Five Resistors, and 'Penny Electrodes' « Adafruit Industries – Makers, hackers, artists, designers and engineers!
Citizen Science — DIY ECGs - Make:
DIY ECG with 1 op-amp
Disposable ECG Electrodes Pack - DFRobot
Buy GENERIC DIY AD8232 ECG Measurement Module Pulse Heart Monitor Biological Signal Collect Develop Kit with Professional EMG Cable Online at Low Prices in India - Amazon.in
DNN Based Homemade ECG - Hackster.io
How to build a DIY heart and activity tracking device | Opensource.com
DIY ECG Machine On The Cheap
Homemade ECG Machine - YouTube
Build your own Electrocardiogram Device | ECG Reader | Getting Started! - YouTube