A new study that appeared today in the peer-reviewed journal of the American Heart Association, found that motion analysis of smartphone-recorded video effectively recognized narrowed arteries in the neck, which are a risk factor for stroke.

Plaque, or fatty deposits, can build up in arteries and obstruct them (stenosis). Narrowed arteries in the carotid artery (located in the neck) can result in an ischemic stroke, which occurs when a blood vessel supplying the brain becomes clogged with a clot. Ischemic strokes account for around 87% of all strokes.

Dr. Hsien-Li Kao, the study’s lead author, says, “Between 2% and 5% of strokes each year occur in people with no symptoms, so better and earlier detection of stroke risk is needed.”

For Kao and team it was “an exciting ‘eureka’ moment”. 

Ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) are the only methods of diagnosis that can be used right now.

“Analysis of video recorded on a smartphone,” according to the author, “is non-invasive and easy to perform, so it may provide an opportunity to increase screening. Though more research and development are needed, the recordings and motion analysis may be able to be implemented remotely, or a downloadable app may even be feasible.”

Kao said that the arteries in the neck are right under the skin, and changes in the speed and pattern of blood flow through them can be seen in the way the skin moves. These variations, nevertheless, are too minute to be seen with the naked eyes.

In this study, which was done between 2016 and 2019, tiny variations in pulse characteristics on the skin’s surface were discovered using motion magnification and pixel analysis.

The study included 202 Taiwanese people (average age, 68; around 79% men) who received medical care at a single Taiwanese hospital. Participants were divided into two groups: 54% had substantial carotid artery stenosis, defined as having at least 50% blockage that was previously detected by ultrasonography, and 46% did not.

Participants laid on their backs with their heads leaned back in a specially designed box to collect recordings with the least amount of ambient noise possible.

The box was equipped with an Apple iPhone 6, 64GB, which was used to record a 30-second video of the subject’s neck. According to Kao, researchers picked a phone from a previous generation because they assumed it would be more widely used by the typical person.

In the group of people known to have carotid artery stenosis, researchers discovered that the video motion analysis system had an 87% accuracy rate for diagnosing stenosis. All study subjects additionally underwent typical Doppler ultrasonography examinations to assess and validate the video motion analysis estimations as well as to confirm artery narrowing.

“More research is needed to determine whether video recorded on smartphones is a promising approach to help expedite and increase stroke screening,” Kao adds. “Carotid artery stenosis is silent until a stroke happens. With this method, clinicians may be able to record a video of the patient’s neck with a smartphone, upload the videos for analysis and receive a report within five minutes. The early detection of carotid artery stenosis may improve patient outcomes.”

The study had a number of limitations, including the small number of individuals who were all deemed to be at high risk for a cardiovascular incident. Additionally, the results of the video study may be impacted by the fact that neck length and neck angle were not examined. Since a common lighting technique was employed for this evaluation, Kao claims that skin tone is unlikely to prevent applications from being used by a larger demographic.

Image Credit: Getty

You were reading: Science Finds A New Way To Detect Stroke Risk Early Using Smartphones