Several years ago, researchers developed a wearable medical device that is like a kind of medical tattoo or e-tattoo. These devices could be used to monitor physiology, act as a sensor, or stimulate muscles, for example. Scientists at The University of Texas at Austin have been working on an e-tattoo that acts as a heart monitor, and can continuously provide information about heart health to the wearer. Herat disease is still the leading cause of death around the world, and this device might one day help people catch the signs of heart disease at early stages to prevent poor outcomes. The work has been reported in Advanced Electronic Materials.
"Most heart conditions are not very obvious. The damage is being done in the background and we don't even know it," said lead study author Nanshu Lu, a professor in the Department of Aerospace and Engineering Mechanics. "If we can have continuous, mobile monitoring at home, then we can do early diagnosis and treatment, and if that can be done, 80 percent of heart disease can be prevented."
This latest version of the device is mobile and wireless. It contains circuits and sensors that can easily stretch as the body moves, and is attached to the chest reversibly with medical dressing. The researchers noted that this device is more comfortable for patients compared to other heart monitors that are now in use. It only weighs 2.5 grams (0.08 ounces) and is powered by a penny-sized battery, which gives it a 40 hour working life. Patients can easily change these batteries themselves.
Clinicians can run various tests on patients, but signs of heart disease might be missed because they aren't obvious when a patient is in for a visit. By constantly monitoring heart function, an e-tattoo can provide a far more complete picture of an individual's heart heath status.
The e-tattoo measures the heart in two ways: with an electrocardiogram (ECG) of the heart's electrical signal, and a seismocardiogram (SCG) of the heart valves' acoustics. The SCG can provide the same kind of information that a doctor gets from a stethoscope, and ECG data can be obtained with many mobile devices like Apple watches. But this is the first mobile monitor to capture both ECG and SCG data. Together, they can tell clinicians about cardiac time intervals, which are an indicator of cardiovascular disease.
"Those two measurements, electrical and mechanical, together can provide a much more comprehensive and complete picture of what's happening with the heart," Lu said. "There are many more heart characteristics that could be extracted out of the two synchronously measured signals in a noninvasive manner."
The device has now been tested on five healthy volunteers and was found to have low error rates compared to other devices. Additional testing and validation will be required before it's available to patients, but the researchers have seen success with their efforts so far and we're likely going to hear more about this e-tattoo in the future.