Can Tattoos Accurately Measure Blood Pressure?

A team of researchers in Texas has developed a tattoo that can reportedly measure blood pressure continuously and more comfortably than a smartwatch.

Researchers at the University of Texas at Austin and Texas A&M University have created an electronic tattoo that can be worn on the wrist comfortably for hours while providing accurate, continuous blood pressure measurements.

“Blood pressure is the most important vital sign you can measure, but the methods to do it outside of the clinic passively without a cuff, are very limited,” Deji Akinwande, a professor in the department of electrical and computer engineering at UT Austin and one of the co-leaders of the project, said in a press release.

The project is documented in a new paper published recently in Nature Nanotechnology.

Left untreated, high blood pressure can lead to serious heart ailments. Traditional blood pressure checks only measure brief moments in time, while continuous measurements can provide greater insights.

“Taking infrequent blood pressure measurements has many limitations, and it does not provide insight into exactly how our body is functioning,” Roozbeh Jafari, a professor of biomedical engineering, computer science and electrical engineering at Texas A&M and co-leader of the project, said in the press release.

One of the more talked-about possibilities for continuous blood pressure monitoring in recent years has been smartwatches. But the Texas researchers found that smartwatches are not ready for the task.

"The watches slide around on the wrist and might be far from arteries, making it hard to deliver accurate readings," the press release noted. "The light-based measurements can falter in people with darker skin tones and/or larger wrists."

The key ingredient in e-tattoo is graphene, described as one of the strongest and thinnest materials in existence. It's similar to graphite contained in pencils, but the atoms are precisely arranged in thin layers.

The e-tattoos consist of a sticky, stretchy material containing the sensors, which can be comfortably worn for long periods without sliding around.

The device measures blood pressure by injecting electrical current into the skin and analyzing the body's response, a phenomenon known as bioimpedance. Researchers used a machine learning model to obtain and analyze blood pressure readings.

The research was supported by grants from the Office of Naval Research, the National Science Foundation and the National Institutes of Health.