A novel contact-free atrial fibrillation monitor: a pilot study

Abstract

Aims: Atrial fibrillation (AF) is a major cause of morbidity and mortality. Current guidelines support performing electrocardiogram (ECG) screenings to spot AF in high-risk patients. The purpose of this study was to validate a new algorithm aimed to identify AF in patients measured with a recent FDA-cleared contact-free optical device.

Methods and results: Study participants were measured simultaneously using two devices: a contact-free optical system that measures chest motion vibrations (investigational device, 'Gili') and a standard reference bed-side ECG monitor (Mindray^®). Each reference ECG was evaluated by two board certified cardiologists that defined each trace as: regular rhythm, AF, other irregular rhythm or indecipherable/missing. A total of 3582, 30-s intervals, pertaining to 444 patients (41.9% with a history of AF) were made available for analysis. Distribution of patients with active AF, other irregular rhythm, and regular rhythm was 16.9%, 29.5%, and 53.6% respectively. Following application of cross-validated machine learning approach, the observed sensitivity and specificity were 0.92 [95% confidence interval (CI): 0.91-0.93] and 0.96 (95% CI: 0.95-0.96), respectively.

Conclusion: This study demonstrates for the first time the efficacy of a contact-free optical device for detecting AF.

Keywords: Camera; Contact free; Heart rate; Laser; Respiratory rate; Vital signs.

Graphical abstract

Figure 1

Gili Pro BioSensor. (A) Gili sensing unit. (B) Measurement setup.

Figure 2

Comparative synchronized signals derived from electrocardiogram, Gili (investigational device), and photoplethysmogram for patients with and without atrial fibrillation. The red dotted lines mark the R-waves on the electrocardiogram.

Figure 3

Study flowchart.

Figure 4

Receiver-operator characteristics curve depicting potential performance of the Gili atrial fibrillation algorithm when compared to cardiologist over-read electrocardiogram.