Just take a smartphone selfie to measure your blood pressure?

Blood pressure is an important human indicator for various diseases and health conditions. High blood pressure that exceeds the normal range is considered one of the lifestyle-related diseases. In order to easily measure such blood pressure, a technology to measure blood pressure by simply photographing one’s face with a smartphone camera has been developed.

Researchers at the University of Toronto Ontario Institute of Education originally developed a non-contact lie detector. He tried to create a system that detects whether humans are lying using a technique called transdermal optical imaging, TOI, but he said he realized that the system he was developing was effective for measuring blood pressure.

If blood pressure exceeds the standard, it is more likely to lead to health problems such as heart attack or stroke. People benefit from being able to measure blood pressure easily. Lie detectors are only useful for some, but blood pressure measurements can benefit more people. Accordingly, they began to study how to use TOI to measure blood pressure rather than a lie detector.

TOI is paying attention to the fact that the facial skin is translucent. When light is received on the face, the skin is transparent and the red light is reflected by hitting the red hemoglobin contained in the blood flowing through the blood vessels. By continuously photographing the face with a smartphone, the optical sensor mounted on the smartphone can capture the red light of hemoglobin and measure blood flow under the skin.

To prove the effectiveness of the system developed by the research team, an experiment was conducted on 1,328 Canadian and Chinese people. The subject took a picture of his/her face with an iPhone for 2 minutes and measured his blood pressure with a system developed. The system measurement results were compared with the existing blood pressure measurement device results.

As a result, the system developed by the research team was able to measure systolic blood pressure, diastolic blood pressure, and pulse pressure with 95-96% accuracy. It is said that in the video captured with the newly developed technology, it was possible to see how blood was flowing in other parts of the face. When you take a picture of your face with a smartphone, you can use TOI to detect blood flow under your skin and measure blood pressure from changes in blood flow.

Since blood pressure measurement using a smartphone is practical, a startup called Neurologix was established in cooperation with the University of Toronto. Based on the developed system, this place has developed and released a smartphone app for blood pressure measurement called Anura . Anura measures the stress level and the like during a 30-second video shoot. It is expected to release a multilingual app that includes blood pressure measurement this fall.

By making it possible to easily measure blood pressure with an app for smartphones, medical services can be provided to people who have been restricted from access to medical care. Of course, the research team said that data privacy is important for healthcare apps.

Smartphone blood pressure measurement is useful, but additional research is needed to improve measurement precision using TOI. Related information can be found here .