ECG

The electrocardiogram, or ECG / EKG are a surface measurement of the electrical potential generated by electrical activity in cardiac tissue. Current flow, in the form of ions, signals contraction of cardiac muscle fibers leading to the heart's pumping action. The ECG is a valuable, non-invasive diagnostic tool which was first put to clinical use in 1913 with Einthoven's invention of the string galvanometer. The results below show a reproduction of one of Einthoven's original traces.

Getting back to electronics, let's talk our way through the circuit we're using to monitor the minute electrical impulses that are present due the action ...