Non-contact Atrial Fibrillation Detection from Face Videos by Learning Systolic Peaks

Objective: We propose a non-contact approach for atrial fibrillation (AF) detection from face videos. Methods: Face videos, electrocardiography (ECG), and contact photoplethysmography (PPG) from 100 healthy subjects and 100 AF patients are recorded. All the videos in the healthy group are labeled as healthy. Videos in the patient group are labeled as AF, sinus rhythm (SR), or atrial flutter (AFL) by cardiologists. We use the 3D convolutional neural network for remote PPG measurement and propose a novel loss function (Wasserstein distance) to use the timing of systolic peaks from contact PPG as the label for our model training. Then a set of heart rate variability (HRV) features are calculated from the inter-beat intervals, and a support vector machine (SVM) classifier is trained with HRV features. Results: Our proposed method can accurately extract systolic peaks from face videos for AF detection. The proposed method is trained with subject-independent 10-fold cross-validation with 30s video clips and tested on two tasks. 1) Classification of healthy versus AF: the accuracy, sensitivity, and specificity are 96.16%, 95.71%, and 96.23%. 2) Classification of SR versus AF: the accuracy, sensitivity, and specificity are 95.31%, 98.66%, and 91.11%. Conclusion: We achieve good performance of non-contact AF detection by learning systolic peaks. Significance: non-contact AF detection can be used for self-screening of AF symptom for suspectable populations at home, or self-monitoring of AF recurrence after treatment for the chronical patients.