More than 360,000 American deaths in 2013 included high blood pressure as a primary or contributing cause. About 7 of every 10 people having their first heart attack have high blood pressure, and about 8 of every 10 people having their first stroke have high blood pressure. Approximately 7 of every 10 people with chronic heart failure have high blood pressure.
Since 1999, more people with high blood pressure have become aware of their condition and have sought treatment. Unfortunately, about 1 of 5 adults with high blood pressure still are unaware of their condition.
Some doctors have begun asking patients to measure their blood pressure at home for a short period of time, usually two weeks, to find out what the readings are away from the office or clinic. Blood pressure readings taken at home are often lower than those taken at a doctor’s office and may provide a more accurate picture of a patient’s blood pressure.
During 2009-2010, approximately 32% of adults aged 18 years and older with hypertension reported that they monitored their blood pressure at home at least once a month.
Women with hypertension were more likely to monitor their blood pressure than men with hypertension (37% versus 28%). When combined with clinical support, this strategy can enhance the quality and accessibility of care for people with high blood pressure and improve blood pressure control.
However, according to Kang Lee, Ph.D., professor and research chair in developmental neuroscience 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' suggestions to take multiple measurements each time.
In this study, Lee and colleagues measured the blood flow of 1,328 Canadian and Chinese adults by capturing two-minute videos using an iPhone equipped with transdermal optical imaging software. They then compared systolic, diastolic, and pulse pressure measurements captured from smartphone videos to blood pressure readings using a traditional cuff-based continuous blood pressure measurement device.
The researchers used the data to teach the technology of accurately determining blood pressure and pulse from facial blood flow patterns. They noted that transdermal optical imaging usually predicted systolic blood pressure with about 95% accuracy and diastolic blood pressure with pulse pressure at about 96% accuracy.
It’s important to note that the researchers videoed faces in a well-controlled environment with fixed lighting, so whether the technology can accurately measure blood pressure in less controlled environments, including homes, is yet unclear. Also, while the study participants had different skin tones, the sample lacked participants with either extremely dark or fair skin.
This study shows that facial video can contain some information about systolic blood pressure. If future studies confirm similar results in hypertensive patients and with video camera measurements made during daily life, then maybe obtaining blood pressure information with a click of a camera will become as common as texting.
