One of the fastest growing sectors is healthcare. And one of the biggest growth areas for wearable tech is heart rate monitoring. The combination of the two could open new opportunities for activewear and intimate apparel.
Despite progress in sensors that offered heart rate monitoring for hobbyists, or even athletes, sensors still have not been able to provide 'medical grade' accuracy.
That could be changing.
Flexible sensors are helping to create new opportunities for integrating advanced monitoring technologies into everyday items. Sales of smart garments have surged from barely measurable in 2014 to an estimated $19 million shipments by 2022, according to a report from Gartner.
A team at Draper (USA) and the University of Colorado Boulder (USA) is applying neuroscience and psychophysiology to build responsive technologies like those integrated in smart textiles. They found that wearable sensor systems don’t seem to perform as well in monitoring heart rates as traditional electrodes.
Katya Arquilla, who designs sensor systems for human spaceflight as a Draper Fellow, tested the feasibility of electrocardiogram (ECG) monitoring with sewn textile electrodes instead of traditional gel electrodes in a 3-lead, chest-mounted configuration.
“The critical question is whether a sewn textile electrode can perform ECG monitoring to the same fidelity for the desired metrics as a traditional electrode. Commercially available wearables are usually incapable of detecting the full ECG waveform,” according to Ms. Arquilla.
Previous Tech Wasn't Accurate Enough
- Conductive ink-based electrodes, which can be printed onto the fabric surface, tend to crack, causing breaks in the conductive surface and changes in resistance during movement.
- Planar-fashionable circuit boards (P-FCBs), which similarly print onto the fabric surface, also require advanced manufacturing methods to produce the conductive paste.
A New and Better Solution
The solution the team devised involved fabricating “dry” electrodes that are directly integrated in clothing.
“Because our device conforms to the skin, it avoids noise and artifact issues that normally occur due to the motion of similar dry electrodes across the skin. The device ultimately should be able to provide accurate signals from a person who is walking, running or climbing stairs," said Allison Webb.
The device underwent a battery of validation tests, including ECG monitoring, comfort surveys with human subjects, stretch testing and wash cycling. Device performance matched the traditional electrode in being able to detect the full ECG waveform.
Doctors prescribe these garments to help monitor patients either during the post treatment period or as part of a long term healthcare program.