Presented at the Ubicomp 2019 conference, this smart sleepwear is able to analyze different vital functions of our body, such as heart rate and breathing rate. A valuable aid for elderly patients with sleep disorders.
Pajamas capable of recording in real time and analyzing our physical and physiological constants during our sleep: this is what the inventors of “Phyjama”, the first intelligent pajamas, promise.
As connected wearables promise to be the future of vital signs monitoring and healthcare personalization, researchers at the University of Massachusetts Amherst have just developed the first smart sleepwear.
Made from a textile capable of detecting physiological functions, this “Phyjama” was presented at the conference Ubicomp 2019 which was taking place this week in London. It is also the subject of a study published in Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies (IMWUT).
A technology based on the pressures of the textile on the body
To develop these pajamas 2.0., the two students behind the project and their teachers had to ask themselves the right questions. Among them: how to create a connected nightwear that remains loose and is pleasant to wear?
“The challenge we faced was to get useful signals without changing the aesthetics or the feel of the textile, explains Prof. Trisha L. Andrew, materials chemist. In general, people assume that smart textiles make refers to very tight-fitting garments in which various sensors are embedded to measure physiological and physical signals, but this is clearly not a solution for everyday clothing and, in particular, sleepwear”.
The researchers found, however, that even when worn loosely, the fabric of the Pajama was pressed against the body during sleep. “This includes the pressure exerted by the torso against a chair or bed, the pressure when the arm rests at the side of the body during sleep, and the light pressure of a blanket on sleepwear”, details the chemist of the materials Deepak Ganesan, who co-supervised this work.
“These pressurized regions of the textile are potential places where we can measure ballistic movements caused by heartbeats and respiration, he continues, and these can be used to extract physiological variables. The difficulty is that these signals can be individually unreliable, especially in loose clothing, but signals from many sensors placed on different parts of the body can be intelligently combined to achieve a more accurate composite reading.”
A valuable tool for the elderly
During the conference, the researchers explained that they realized that there was no tissue-based method to detect continuous and dynamic changes in pressure, especially on the small signals that they needed to measure. . So they designed a new fabric-based pressure sensor and combined it with a triboelectric sensor – a sensor activated by a change in physical contact – to develop a distributed sensor array that could be embedded in loose clothing like a pyjamas.
This combination allowed them to detect physiological signals in many different postures: heartbeats were thus detected with great precision, as well as the respiratory rate.
According to them, this Pajama could become a valuable tool for measuring sleep quality and analyzing vital functions. “We expect these advances to be particularly useful for monitoring elderly patients, many of whom suffer from sleep disturbances,” explains Prof. Andrew. “Current generation wearables like smartwatches are not ideal for this population as older people often forget to wear them regularly or resist wearing additional devices, when sleepwear is already an integral part of it. of their daily lives. Also, your watch cannot tell you what position you sleep in and whether your sleeping position is affecting your quality of sleep. Our Pajamas can.”
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