Getting a new tattoo isn’t just about looking cool (or making a decision you’ll regret years later) — it can also save your life. At least, that’s the idea behind a new electronic tattoo that can measure your blood pressure continuously and discreetly.
In an article published this Monday in the magazine Nature Nanotechnology, a team from the University of Texas at Austin and Texas A&M University has developed a device that can be attached to the skin of the wrist and worn comfortably for up to 24 hours. It can continuously monitor blood pressure with incredible accuracy, potentially helping to diagnose underlying problems and inform treatment of patients with serious heart conditions. The researchers hope it will pave the way for a blood pressure monitor that doesn’t require a cuff device like a traditional cuff.
“Blood pressure is an important metric,” Roozbeh Jafari, a professor of biomedical engineering at Texas A&M and co-author of the study, told The Daily Beast. “This gives us a holistic view of the entire cardiovascular system. But if you want to measure it, just one or a few measurements a day is not enough, and cuff-based solutions are inconvenient, uncomfortable, and impractical.
In fact, when it comes to the world of blood pressure monitoring, having a cuffless device is the “holy grail,” said Jafari. This is because handcuffed devices are often uncomfortable to wear, and heart monitoring products such as smartwatches also tend to move around too much on the wrist to provide accurate data.
That’s why the Texas team turned to graphene – a material similar to graphite pencils – to create a tattoo that can be applied directly to a person’s arteries on their wrists. Not only is it incredibly durable, it’s also the thinnest material in the world. This makes it perfect to be used in an electronic tattoo as it allows the wearer to not even feel it on their skin.
It is also applied just like a temporary tattoo: a piece of paper is placed over the spot on your wrist, which is then wiped off with a small amount of water. After a few seconds, the paper is removed and voila – you have a new cyberpunk tattoo. Unfortunately, though, it’s still not enough to measure your heart rate.
“We have these circuits that we need to connect to the skin to get information about blood pressure,” Kaan Sel, a Texas A&M electrical and computer engineering researcher and co-author of the study, told The Daily Beast. “The tattoo is the interface. Once the tattoos are transferred, it gives that long-term, reliable connection to the skin.”
The circuits lead to a small electronics box that transmits the information to a computer, which uses machine learning to produce the biometric data. The entire system works by sending an electrical current to the skin of the arm that allows it to detect changes in the volume of the arteries in the arm, that is, changes in blood pressure.
“You have blood that pumps through your arteries,” Dmitry Kireev, a bioelectronics researcher at UT in Austin and co-author of the study, told The Daily Beast. “It will change the volume of the arteries and that’s what we capture.”
Remember, this is just a prototype. The team hopes to further refine the system so that it can be adapted to smart watches, to allow for much more accurate blood pressure readings. This would represent a huge improvement over current smartwatch technology that relies on an optical system to detect your heart rate – which is problematic for a number of reasons.
On the one hand, the optical system is based on the reflection of light on your skin “but that light only penetrates to a certain extent,” said Sel. Those with darker skin tones also have a noticeably harder time with these systems.
The e-tattoo could lay the groundwork for a commercial cuffless blood pressure monitor that will allow patients to be able to detect and send vital biometric data to their doctors without having to be strapped to a heavy machine. That data could include things like “muscle contractions, hydration, changes in tissue composition, or even respiration,” according to Sel.