DOCTORS can now tell if a patient is suffering from a potentially lethal heart condition just by looking at their face.
A pilot project shows that subtle changes in skin colour can reveal uneven blood flow caused by atrial fibrillation. The technology was developed in a partnership between the University of Rochester school of medicine and dentistry in the United States and Xerox.
Doctor Jean-Philippe Couderc, of Rochester University, said: “This technology holds the potential to identify and diagnose cardiac disease using contactless video monitoring.
“This is a very simple concept, but one that could enable more people with atrial fibrillation to get the care the care they need.”
Atrial fibrillation is an irregular or sometimes rapid heart rate that commonly causes poor bloodflow to the body. It occurs when erratic cardiac electrical activity causes the upper and lower chambers of the heart to beat out of sync.
While the condition can be readily diagnosed, in many people it goes undetected.
It is estimated that 30 per cent of people with the condition do not know they have it. If untreated, the condition places people at a significantly higher risk of blood clots and stroke.
The technology used in the study employs a software algorithm developed by Xerox that scans the face and can detect changes in skin colour that are imperceptible to the naked eye. All that is required is that the subject remains still for 15 seconds.
Sensors in digital cameras are designed to record three colours: red, green, and blue. Haemoglobin – a component of blood – absorbs more of the green spectrum of light and this subtle change can be detected by the camera.
It turns out that the face is the ideal place to detect this phenomenon, because the skin is thinner than in other parts of the body and blood vessels are closer to the surface.
The study participants were simultaneously hooked up to an electrocardiogram (ECG) so that results from the facial scan could be compared to the actual electrical activity of the heart.
The researchers, whose findings were published online in the journal Heart Rhythm, found that the colour changes detected by video monitoring corresponded with an individual’s heart rate as detected on an ECG.
Irregular electrical activity found in people with atrial fibrillation could be identified by observing pulses of blood flowing through facial veins as it absorbed or reflected green light with each heartbeat.
The study found that the video monitoring technique – which researchers have called videoplethymography – had an error rate of 20 per cent, comparable to the 17 to 29 per cent error rate associated with automated ECG measurements.
While the pilot study was only conducted on 11 people and intended to demonstrate that the technology was feasible, the researchers now plan to evaluate the technology on a larger study population, including those without atrial fibrillation.
Dr Couderc added: “As is the case with many new technologies, we believe that we can significantly improve its accuracy and usability.”