Using the smartphone camera to monitor heart rate and rhythm in heart failure patients

Telemonitoring is a tool with proven results demonstrating clinical benefits in reducing mortality and hospitalizations. In this context, heart rate and rhythm are vital signs of utmost importance for monitoring a patient's condition. Recent advances in mobile technologies have allowed smartphones to be of great usage in this scenario, given its processing power, connectivity capabilities, sensor hardware and camera quality. This paper describes the usage of a smartphone camera to detect the heart rate and rhythm of a patient. A photoplethysmogram signal is obtained with the user's fingertip placed over the smartphone camera. An evaluation has been performed on 43 subjects with heart failure. For each patient the signal obtained with the smartphone camera was compared with the ECG signal acquired in hospital environment. Results demonstrate the heart rate can be effectively estimated using that approach with an error rate of 4.75%. Atrial Fibrillation detection with our method achieved a specificity of 97% and sensitivity of 75%.