Blood pressure is one of the most important indicators of heart health, but it's tough to frequently and reliably measure outside of a clinical setting. For decades, cuff-based devices that constrict around the arm to give a reading have been the gold standard. But now, researchers at The University of Texas at Austin and Texas A&M University have developed an electronic tattoo that can be worn comfortably on the wrist for hours and deliver continuous blood pressure measurements at an accuracy level exceeding nearly all available options on the market today.
[...] Graphene is one of the strongest and thinnest materials in existence, and it is a key ingredient in the e-tattoo. It is similar to graphite found in pencils, but the atoms are precisely arranged into thin layers.
[...] The device takes its measurements by shooting an electrical current into the skin and then analyzing the body's response, which is known as bioimpedance. There is a correlation between bioimpedance and changes in blood pressure that has to do with blood volume changes. However, the correlation is not particularly obvious, so the team had to create a machine learning model to analyze the connection to get accurate blood pressure readings.
In medicine, cuff-less blood pressure monitoring is the "holy grail," Jafari said, but there isn't a viable solution on the market yet. It's part of a larger push in medicine to use technology to untether patients from machines while collecting more data wherever they are, allowing them to go from room to room, clinic to clinic and still get personalized care.
Kireev, Dmitry, Sel, Kaan, Ibrahim, Bassem, et al. Continuous cuffless monitoring of arterial blood pressure via graphene bioimpedance tattoos, Nature Nanotechnology (DOI: 10.1038/s41565-022-01145-w)