For some time now, smartphone apps have been used to measure blood pressure; this type of contactless blood pressure tracking has been something of a Holy Grail for cardiologists and the tech industry. But the technique most mobile devices rely on, photoplethysmography (PPG), has its limitations: using a camera to detect changes in light reflected off of skin to gauge blood flow has accuracy issues. To get better results, researchers at the University of South Australia (UniSA) and Baghdad’s Middle Technical University turned to AI. They designed a no-contact blood pressure measuring system which they say is about 90% as accurate as a digital sphygmomanometer.
To get these better results, researchers looked to the forehead; their system uses a digital camera to film two areas of a person’s forehead, extracting cardiac data in just ten seconds. AI algorithms do the work of analyzing the information. To test their system, the research team performed a study with 25 people — all of whom had different skin tones — under different ambient light conditions. The results? Blood pressure readings using the new system were strikingly similar to those taken using a commercial sphygmomanometer.
UniSA researcher Professor Javaan Chahl says of the need for such a measuring method, “The health sector needs a system that can accurately measure blood pressure and assess cardiovascular risks when physical contact with patients is unsafe or difficult, such as during the recent COVID outbreak.” And the everyday need to monitor blood pressure is just as great for many patients; according to the Centers for Disease Control and Prevention (CDC), almost half of adults in America (47%) have hypertension, and only about 1 in 4 of these folks have their high blood pressure under control. The CDC estimates that the high blood pressure issue costs around $131 billion in the U.S. each year.
The staggering price tag makes a low-cost, hassle-free solution to accurately monitor blood pressure all the more crucial. About 85% of Americans own smartphones, but, according to a recent National Poll on Healthy Aging, only about 55% of people who have been diagnosed with high blood pressure own blood pressure monitors. Professor Chahl adds, “Monitoring blood pressure is essential to detect and manage cardiovascular diseases, the leading cause of global mortality, responsible for almost 18 million deaths in 2019…If we can perfect this technique, it will help manage one of the most serious health challenges facing the world today.”