AJ PHOTO / HOP. AMERICAIN / SCIENCE PHOTO LIBRARY AJ PHOTO / HOP. AMERICAIN / SCIENCE PHOTO LIBRARY
ECG electrodes on a patient's chest. ECG (electrocardiography) uses a series of electrodes to pick up the electrical activity of the heart muscle. The characteristic trace produced as the heart beats and relaxes can be studied for signs of a heart disorder.
Model release not required. Property release not required.