When we think of embroidery, we usually think of intricate and carefully woven thread designs sewn into clothing, but in this case, scientists figured out a way to make it measure heart rates as well.
Swiss researchers have developed a fiber optic material that is fast and easy to produce, and can either be woven, knit, or embroidered into any kind of fabric, which can then be used as a wearable heart sensor. These sensors are also washable, even by harsh hospital grade detergents.
“From the side of our medical partners, that’s the first thing that they ask us,” says Luciano Boesel from the Swiss Federal Laboratories for Materials Science and Technology, Dübendorf (EMPA). The clothing needs to be washable, especially in healthcare environments where diseases can easily cling into fabrics and leave the wearer susceptible to these diseases.
This study, which was published in the Journal of the Royal Society Interface, is part of a larger project which aims to develop sensors that can monitor vital signs in paraplegic patients (those with impairments in their motor or sensory functions of their lower extremities), as they often run into problems with traditional finger-sensors which can cause allergic reactions and sores when rubbed against their skin.
Source: Popular Science
The material works by first melt-spinning two different polymers into a fiber optic thread (Melt spinning is the process of melting materials and then spinning them out into a thread of their desired shape and size). The first polymer is a coating whilst the second one is a fiber optic polymer that is capable of transmitting light over long distances. These materials had to be chosen carefully, as “Materials that are good for melt spinning aren’t usually good for optical fibers,” Boesel explains. The thread is then ready to be fashioned into a sensor and woven into a piece of fabric.
The researchers had embroidered their prototype of the material into a simple knit hat that was placed onto someone’s forehead. The bends within the thread allows an LED light to escape the fiber and travel into the skin. That light is then reflected off a person’s pulse and detected by the sensor made out of the same kind of thread.
Source: Popular Science
The tests have been compared to a traditional fingertip-worn heartbeat sensor, and the results have proven to be accurate. Not only that, it’s also more comfortable. The sensor was dragged against replicas of dry and sweaty skin, and they have found that it causes less friction (which is the main cause of irritation in paraplegic patients) than the usual hospital bedsheets.
Whilst this sensor can only detect heartbeats, the researchers hope to improve the technology to include the tracking of oxygen levels and the pressure in tissues.
Article Sources:
