Did you ever think you could one day monitor Blood Pressure (BP) as easily as taking a video selfie? Interestingly, researchers, including an Indian origin, have tested a technology known as transdermal optical imaging that measures blood pressure by detecting blood flow changes in facial videos captured in smartphones.
"This study shows that facial video can contain some information about systolic blood pressure," said Indian-origin researcher Ramakrishna Mukkamala, Professor at the Michigan State University.
According to researchers, the ambient light penetrates the person’s outer layer of skin allowing digital optical sensors in smartphones to visualize and extract patterns of blood flow, which transdermal optical imaging models can use to foretell blood pressure.
"High blood pressure is a major contributor to cardiovascular disease - a leading cause of death and disability. To manage and prevent it, regular monitoring of one's blood pressure is essential," said study’s lead author Kang Lee, Professor at the University of Toronto in Canada.
"Cuff-based blood pressure measuring devices, while highly accurate, are inconvenient and uncomfortable. Users tend not to follow American Heart Association guidelines and device manufacturers' suggestion to take multiple measurements each time," Lee said.
The researchers measured the blood flow of 1,328 Canadian and Chinese adults by capturing two-minute videos using an iPhone provided with transdermal optical imaging software.
Also, for the study, published in the journal Circulation: Cardiovascular Imaging, the researchers compared diastolic, systolic, and pulse pressure measurements captured from smartphone videos to blood pressure readings making use of a traditional cuff-based uninterrupted blood pressure measurement device.
The researchers used the data to guide the technology on how to accurately determine blood pressure and pulse from facial blood flow patterns.
According to Lee, the researchers found that on average, transdermal optical imaging predicted systolic blood pressure with nearly 95 percent accuracy and diastolic blood pressure with pulse pressure at nearly 96 percent accuracy. The technology's high accuracy is within international standards for devices used to measure blood pressure.
The research team carried out the video recording of faces in well-controlled surroundings with fixed lighting, therefore it is ill-defined whether the technology can accurately measure blood pressure in less controlled surroundings, as well as homes.
Besides, while the participants in the study had a variety of skin tones, the sample lacked subjects with either exceedingly dark or fair skin.
By Sowmya Sangam
