Smartphone Application Detects Atrial Fibrillation

A novel cardiac application for the iPhone and most smartphones detects not only heart rate, but also heart rhythm, respiration rate, and blood oxygen saturation (SpO2) using the phone’s built-in video camera.

Developed by researchers at the Worcester Polytechnic Institute (WPI, MA, USA), the app uses the smartphone’s camera and light-source, detecting small changes in skin color and the appearance of underlying blood vessels at 30 frames-per-second (fps) when the index finger is held over the camera for a minute or two. Due to the nature of the light-source, the app will be compatible with the iPhone and most other smartphones, but not with the iPad, which uses a different enclosure.

The phone will display a green indicator when the reading is considered normal and a red one when an abnormal heart rhythm is detected. A numeric heart rate is also displayed, along with a verbal description of the rhythm on a slider scale. A symptom recorder is also included, which allows sensations and other symptoms to be typed in for reference. The data can be emailed to a doctor or clinic, or kept as a record for future visits.

Although not designed to replace any diagnostic devices, it could be used as a screening tool, as well as for use for patients with paroxysmal atrial fibrillation (AF), registering intermittent AF episodes over longer periods of time, either in existing patients (for monitoring purposes) or in new patients for detection of AF. For these purposes, a watchband type device might function to continuously acquire data, or the app could be used once the patient experiences symptoms.

The app has been tested in 60 patients with AF at the at the University of Massachusetts (UMass; USA) Memorial Medical Center. In all patients, AF was correctly identified, giving it 100% sensitivity. The app is pending approval by the US Food and Drug Administration (FDA).

“AFib is so common, but many people have no symptoms, or subtle symptoms like getting winded. This tool will be very helpful because AFib is so hard and expensive to diagnose,” said David McManus, MD, a cardiologist at UMass, chief clinician of the clinical trial of the app. “The time required to hold one’s finger down will likely be decreased in the final version of the app, perhaps to a minute or less.”

Related Links:
Worcester Polytechnic Institute
University of Massachusetts