Wrist-located optical device for atrial fibrillation screening: A clinical study on twenty patients

This study aims at evaluating the performances of a wrist-located device to detect atrial fibrillation (AF) based on photoplethysmography (PPG) technology. Twenty patients referred for catheter ablation of cardiac arrhythmias in whom episodes of sinus rhythm (SR) and AF coexisted were screened. Screening included a 12-lead electrocardiogram (ECG) and a PPG device placed at the wrist measuring cardiac pulsatility by means of infrared light. While reference cardiac interbeat (RR) intervals were obtained from the analysis of the ECG signals, RR intervals from the PPG signals were estimated by detecting systolic down-strokes on the optical waveforms. Classification of SR versus AF epochs was obtained via a support vector machine to which features extracted on 10-second windows were provided. Extracted features included mean, standard deviation, minimum, and interquartile range of RR within an epoch. A total number of 2213 epochs (1927 of AF, 286 of SR) were analyzed, providing classification accuracy of 93.85% for the PPG-based classifier and 98.93% for the ECG-based classifier. These preliminary results suggest that a wrist-located PPG-based monitor might be eligible for future screening of AF in large populations.