By Emily Dieckman, Faculty of Engineering
Wearable sensors to monitor everything from step count to heart rate are almost ubiquitous. But for scenarios like measuring the onset of frailty in the elderly, diagnosing life-threatening illnesses early, testing the effectiveness of new drugs, or tracking the performance of professional athletes, medical-grade devices are needed.
Engineers at the University of Arizona have developed a type of wearable device they call a âbiosymbiotic device,â which has several unprecedented benefits. Not only are the devices custom 3D printed and based on wearers’ body scans, but they can also operate continuously using a combination of wireless energy transfer and compact energy storage. The team, led by Philippe gutruf, assistant professor of biomedical genius and Craig M. Berge Faculty Fellow in the College of Engineering, today published its findings in the journal Science Advances.
“There is nothing like it there,” said Gutruf, a member of the university. BIO5 Institute. âWe are introducing a whole new concept of fitting a device directly to a person and using wireless power streaming to allow the device to run 24/7 without ever needing to recharge. “
Custom fit allows precise monitoring
Current portable sensors face various limitations. Smartwatches, for example, need to be charged, and they can only collect a limited amount of data due to their placement on the wrist. Using 3D scans of a wearer’s body, which can be collected via methods such as MRIs, CT scans, and even carefully combined smartphone images, Gutruf and his team can 3D print custom devices that s ‘wrap around various parts of the body. Think of a virtually unnoticeable, lightweight, breathable mesh cuff designed specifically for your biceps, calf, or torso. The ability to specialize sensor placement allows researchers to measure physiological parameters that they might not otherwise be able to.
âIf you want something close to continuous body temperature, for example, you would want to place the sensor in the armpit. Or, if you want to measure how your bicep deforms during exercise, we can place a sensor in devices that can accomplish this, âsaid Tucker Stuart, doctoral student in biomedical engineering and first author of the article. âBecause of the way we make the device and attach it to the body, we are able to use it to collect data that a traditional wrist-mounted wearable device wouldn’t be able to collect. “
Because these biosymbiotic devices are tailored to the wearer, they are also very sensitive. Gutruf’s team tested the device’s ability to monitor parameters, including temperature and blood pressure, as a person jumped, walked on a treadmill, and used a rower. In the rower test, subjects wore multiple devices, depending on the intensity of the exercise and how the muscles distorted in fine detail. The devices were accurate enough to detect changes in body temperature induced by climbing a single staircase.
Continuous, wireless and effortless
Gutruf and his team aren’t the first to adapt wearable devices to track health and bodily function. However, current wearable devices lack the ability to track metrics continuously or with sufficient precision to draw medically meaningful conclusions.
Some wearable devices used by researchers are patches that stick to the skin, but they come off when the skin undergoes its normal shedding process, or sometimes when a subject sweats. Even highly sophisticated portable devices used in clinical settings, such as ECG monitors, face these issues. In addition, they are not wireless, which considerably limits mobility. Patients cannot go about their normal daily lives if they are attached to bulky external devices.
The biosymbiotic device that Gutruf’s team set up uses no adhesives, and it is powered by a wireless system with a range of several meters. The device also includes a small energy storage unit, so it will work even if the wearer goes out of range of the system, including out of the house.
âThese devices are designed to require no interaction with the wearer,â Gutruf said. “It’s as easy as turning the device on. Then you forget it and it does its job.”
This research was funded by the Flnn Foundation Translational Bioscience Seed Grant Pilot Program. The team also worked with Arizona Technology Launch, the university’s commercialization arm, to protect intellectual property and launch a startup to bring technology to market.