Electronic 'tattoo' monitors heart for days
New wearable technology made from stretchy, lightweight material could make heart health monitoring easier and more accurate, a new study reports.
Existing electrocardiogram (ECG) technology hasn’t changed much in almost a century, researchers say.
The new device is so lightweight and stretchable that it can remain over the heart for extended periods with little or no discomfort. It measures cardiac health in two ways, taking electrocardiograph and seismocardiograph readings simultaneously.
Most of us are familiar with the electrocardiogram (ECG), a method that records the rates of electrical activity produced each time the heart beats. Seismocardiography (SCG) is a measurement technique using chest vibrations associated with heartbeats.
A smartphone remotely powers the e-tattoo, which researchers say is the first ultrathin and stretchable technology to measure both ECG and SCG.
“We can get much greater insight into heart health by the synchronous collection of data from both sources,” says Nanshu Lu, an associate professor in the aerospace engineering and engineering mechanics and biomedical engineering departments at the University of Texas at Austin.
ECG readings alone are not accurate enough for determining heart health, but they provide additional information when combined with SCG signal recordings. Like a form of quality control, the SCG indicates the accuracy of the ECG readings.
Although soft e-tattoos for ECG sensing are not new, other sensors, such as the SCG sensor, are still made from nonstretchable materials, making them bulky and uncomfortable to wear.
The new e-tattoo is made of a piezoelectric polymer called polyvinylidene fluoride, capable of generating its own electric charge in response to mechanical stress. The device also includes 3D digital image correlation technology used to map chest vibrations in order to identify the best location on the chest to place the e‐tattoo.
The e-tattoo has another advantage over traditional methods. Usually an ECG measurement requires going into a doctor’s office, where doctors can monitor heart health for only a couple of minutes at a time. Patients can wear the new device for days for constant heart monitoring.
The device is the latest incarnation of Lu’s electronic tattoo technology, a graphene-based wearable device that can be placed on the skin to measure a variety of body responses, from electrical to biomechanical signals.
Lu and colleagues are already working on improvements to data collection and storage for the device, as well as ways to power the e-tattoo wirelessly for longer periods. They recently developed a smartphone app that not only stores the data safely but can also show a heart beating on the screen in real time.
The paper appears in Advanced Science. The Office of Naval Research, the Air Force Office of Scientific Research, the National Science Foundation, and the National Institutes of Health funded the work.