Also a breadboard – but you could just as easily try to Manhattan-style the circuit as well! (Or, you know, one hundred other ways to make it how you make things.) The schematic can be seen b…
Source: Electrocardiography for Cheap: DIY ECG Uses One LM741 Op-Amp, Five Resistors, and ‘Penny Electrodes’ « Adafruit Industries – Makers, hackers, artists, designers and engineers!