Don’t ditch your Fitbit just yet, but a new, wearable fabric technology on the horizon could perform all sensing needs for health and physical activities. Transmitted wirelessly to a smartphone, the steady stream of data could also prove instrumental in personalized telemedicine, allowing the monitoring of patients at home without the need for an in-office visit.
Smart clothing products already exist, but what's different about the garment developed by a team of MIT researchers is that it can simultaneously measure multiple temperature points as well as heartbeat and respiration rate.
A prototype version of the shirt, tested on wearers exercising at a gym, has 30 temperature sensors and an accelerometer. Because the sensors cover a large surface area, the researchers can observe temperature changes in different parts of the body, and how those changes correlate with each other.
“Our approach is unique in the way that the garment is multifunctional and customizable,” said Canan Dagdeviren, the LG Electronics Career Development Assistant Professor of Media Arts and Sciences at MIT. “Due to the modular nature of our system, we can tailor the electronics to cover specific body parts, and it’s also straightforward to add any other available sensing modules based on the specific user’s needs.”
The shirts, said the researchers, can be easily manufactured in different sizes to fit a diversity of age groups and body types.
A load of sensor nodes
The technology, called E-TeCS, is described in a paper recently published in the journal npg Flexible Electronics. Dagdeviren is the senior author and MIT graduate student Irmandy Wicaksono is the lead author of the study. Several MIT undergraduates also contributed to the project through the Undergraduate Research Opportunities Program.
The research was funded by the MIT Media Lab Consortium and a NASA Translational Research Institute for Space Health Seed Grant from the MIT Media Lab Space Exploration Initiative
E-TeCS consists of a stretchy polyester blend fabric—similar to the kind of compression shirts some people wear for workouts—that was chosen for its moisture-wicking properties and ability to conform to the skin. Removable sensors, consisting of long, flexible strips encased in epoxy are woven into narrow channels within the fabric. Small openings in the channels allow for direct contact between the sensors and skin.
Removable sensors, consisting of long, flexible strips encased in epoxy are woven into narrow channels within the fabric of a tshirt to monitor vitals and physical activity.
A detachable wireless module allows the wearer to easily charge the battery via a micro-USB interface in two hours, and it can also be transferred to other garments. “Our approach was to design for ease of use: Make it user-friendly to transmit the data, connect it to a main module that is removable prior to washing, and allow a user to charge the battery through a Micro-USB interface,” Dagdeviren said.
The most critical aspect of the design was the development of the conformable fabric. “In this approach, we had to ensure sufficient pressure of up to 25 mmHG between all of the sensors and the skin in order to ensure accurate sensor readings, but at the same time maintain overall comfort,” said Dagdeviren.
Another design goal was to ensure that the technology could be manufactured using current digital knitting and flexible PCB assembly processes, and that all of the sensors used be readily available, off-the-shelf components. Last summer, several of the researchers spent time at a factory in Shenzhen, China, to experiment with mass-producing the material used for the garments.
“We think our design will be relatively low-cost compared to other techniques, such as microfabrication,” said Dagdeviren. “We envision that the cost of this shirt in the future would be close to the cost of a sweater today.”
As for when it will be ready for use in clinics at home, Dagdeviren estimates that the technology will need several years of further work including clinical trials and more rigorous eletromechanical and washability studies.
As those studies progress, the team plans to develop other types of garments, such as pants, and is working on incorporating additional sensors for monitoring blood oxygen levels and other indicators of health.
There is no word yet on whether the shirt can be customized with the user’s favorite design or sports team logo, making it truly a staple of gym rats everywhere.