The world’s first ring-type heart-monitoring device, CART-I developed by Sky Labs. The CART (Cardio Tracker) – I, a ring-type medical device monitors heart signals and detects diseases by using optical sensors. The photoplethysmography (PPG) sensor in the ring monitors the bloodstream in the finger and continuously measures the irregular pulse waves of atrial fibrillation. Electrocardiogram (ECG) can be also measured by simply placing the fingers on the metal part of the ring. Sky Labs provided its CART-I for clinical research of professor Timothy Betts at Oxford University. Professor Betts plans to conduct a clinical study with Sky Labs CART-I to detect atrial fibrillation symptoms and alert the patients to take anticoagulants when needed.