The Smarthealth Heart Rate Monitor provides fast, accurate heart rate readings thanks to the innovative S-Pulse™ technology, designed to measure the electrical signals on your skin in the same manner that an EKG or electrocardiogram does. While the Smarthealth Heart Rate attaches to your wrist like any other watch, it does not measure or sense your pulse at your wrist. It instead uses S-Pulse™ patented technology to sense your heart rate by measuring your EKG signal.