Jun 29, 2022 08:00:00

Technology to continuously measure blood pressure with 'electronic tattoo' attached to the skin is developed

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Blood pressure ' is an important index of vital activity along with breathing, pulse, and body temperature, and measuring blood pressure is important for understanding various health risks. However, no matter how important it is to measure blood pressure, it is not possible to carry around a blood pressure monitor that is used for health examinations and to measure blood pressure frequently. Therefore, a research team at the University of Texas at Austin has developed an ' electronic tattoo ' that can be attached to the skin to continuously measure blood pressure.

Continuous cuffless monitoring of arterial blood pressure via graphene bioimpedance tattoos | Nature Nanotechnology
https://www.nature.com/articles/s41565-022-01145-w

Blood Pressure E-Tattoo Promises Continuous, Mobile Monitoring --UT News
https://news.utexas.edu/2022/06/20/blood-pressure-e-tattoo-promises-continuous-mobile-monitoring/

People with hypertension regularly take blood pressure measurements to control their medications, as leaving high blood pressure at risk of serious heart disease. However, blood pressure measurement with a device that wraps around the arm can only measure blood pressure at a specific point in time, so it is difficult to grasp how the body actually functions. Deji Akinwande , a professor of electrical and computer engineering at the University of Texas at Austin, said, 'Blood pressure is the most important vital sign that can be measured. It's very limited. '

In recent years, health monitoring using smart watches has become popular, but these devices mainly illuminate the skin with LED lights to monitor heart rate and other factors. However, the smartwatch slides around the wrist and is easy to move, and the position from the artery may fluctuate, so it is not suitable for accurate blood pressure measurement. In addition, light-based measurements may fail due to skin color and wrist thickness.

Therefore, the research team focused on 'electronic tattoo', an ultra-thin wearable device that collects various biometric data by attaching it to the skin or clothes to measure the electrical resistance (

bioimpedance ) of the skin surface. Electronic tattoos using graphene with carbon atoms bonded in a hexagonal grid pattern are extremely thin and lightweight, and because they are made of elastic and sticky material and do not move when attached to the skin, they are suitable as blood pressure measurement devices. It is said that it is suitable.

The electronic tattoo developed by the research team is made of high-quality graphene made by chemical vapor deposition (CVD) , and is a mechanism to measure blood pressure by analyzing the bioimpedance that reacts when an electric current is passed through the skin. We know that there is a correlation between bioimpedance and blood pressure, and the research team created a machine learning model that measures accurate blood pressure from bioimpedance.

The research team reported that they actually applied the developed electronic tattoo to seven subjects and succeeded in measuring blood pressure for an average of 3 hours or more and up to 5 hours.

Roozbeh Jafari , a professor of biomedical engineering, computer science and electrical engineering at the University of Texas at Austin, said, 'Electronic tattoo sensors are light and unobtrusive. I don't look at it and it doesn't move on its own. ' 'All of these data enable us to create'digital twins ' that allow us to predict and see the body's response and response to long-term treatments,' said Akinwande.