Why are graphene tattoos the superior wearable interfaces?

Why are graphene tattoos the superior wearable interfaces?Why are graphene tattoos the superior wearable interfaces? What is it that you can do with graphene tattoos but not with other wearable systems? The answer is cuffless capturing of Blood Pressure! First, let's look into blood pressure (BP). BP is a vital representative sign of your health. If you have any problem with the cardiovascular system, BP will show it. But! To really catch the problem early, you need to measure BP continuously. Can it be done? Well, the modern technology of monitoring the BP is archaic and based on 100 years old sphygmomanometers.

At the free-to-attend TechBlick conference on Wearable Electronics (www.TechBlick.com/wearables), Dmitry Kireev and Deji Akinwande from The University of Texas at Austin and Kaan Sel and Roozbeh Jafari from Texas A&M University will report on a unique technology capable of cuffless monitoring of Blood Pressure. The measurements are performed electrically, using Bioimpedance modality (Bio-Z), and graphene tattoos play the essential role as imperceptible and self-adhesive biointerfaces. The Bio-Z is performed dynamically with >10kHz sampling rate. A change in arterial volume (blood inflow) will affect the measured Bio-Z value.

To capture the arterial Bio-Z, the graphene tattoos are placed on the skin right over the arteries (we got two on each wrist). Here four Bio-Z channels are simultaneously measured. Although the Bio-Z waveform is representative of BP, there is no simple regression. Control BP is measured using a clinical style set-up (Finapres), and we use machine learning to correlate the Bio-Z features with Control BP, building up the so-called ML correlation model. Once the model is built, we can directly estimate BP from only Bio-Z data from the wrist.

And this is where graphene tattoos are ultimately essential compared to anything else. We need the measurements to happen at the precise and unchanging precise locations. Even a 1-mm shift of one electrode will change the signal and ML system, meaning that the correlation is not valid anymore. Graphene tattoos are unique: they self-adhere, and remain at the exact same place. They are transparent, lightweight, and non-irritative. In combination with the Bio-Z methodology, yielding an unprecedented before cuffless BP monitoring system.

Other advantages? electrical measurements are used. Unlike optical (PPG), this work actively measures from deep tissues regardless of a person’s BMI (body mass index) or skin color (PPG fails at darker skin). Overall, this approach reaches an unprecedented before 5+ hours of continuous detection of BP (systolic, diastolic, mean) with Grade-A accuracy!

This technology will be presented at TechBlick's free-to-attend one-day two-track live online conference covering wearable sensors, e-textiles, and printed electronics. See agenda and sign up now www.TechBlick.com/wearables