Atrial fibrillation (Afib) is an abnormal heart rhythm that increases the risk of stroke. Afib affects an estimated 3 million people in the U.S. with the number expected to grow as the population ages. Afib causes up to 20% of the 750,000 strokes that occur in the US annually. Treatment of Afib with anticoagulants has been shown to reduce the stroke risk, however, many people with Afib are not aware that they have Afib and are not treated with anticoagulants. The Afib Watch is a medical device for Afib screening in patients who have had a stroke and in those at high risk for Afib. The Afib Watch will also be branded as a Senior Fitness Watch and will be marketed as a consumer product. The watch will detect the pulse with exercise, count steps and assess postural sway and balance. There will be two versions available. One version will detect irregular heart rhythms and one will be used to diagnose Afib.