How smart are your pyjamas?plainpicture/C. Adler By Donna LuThe pyjamas you wear to bed may soon be able to tell how well you are sleeping. Trisha Andrew and her colleagues at the University of Massachusetts, Amherst, have developed a cotton pyjama shirt that has sensors for monitoring breathing, heartbeat and movement. The shirt can be used to monitor the wearer’s sleep quality, such as the amount of REM sleep they are getting, which is thought to be important for consolidating memories, or if they have breathing issues during the night. Advertisement Five lightweight sensors are sewn into the lining of the shirt. Four of the sensors detect constant pressure, like that of a body pressed against a bed. The fifth, positioned over the chest, senses rapid pressure changes, providing information about heart rate and breathing. The smart pyjamas before a cotton lining was added over the topTrisha L. Andrew The sensors are connected by wires made from thread thinly coated in silver. “They are sewed onto the seams of the shirt, so you don’t see them,” says Andrew. The shirt is fully machine-washable. Signals collected from the five patches are sent to a tiny circuit board that looks and functions like an ordinary pyjama button. The button has a built-in Bluetooth transmitter that sends the data wirelessly to a computer for analysis. The pyjama shirt is still in its early stages – it has been tested overnight on only eight people, and the team is still in the process of ensuring the sensors are accurate for a variety of body shapes and heights. Andrew says the shirt cannot yet be used to diagnose medical issues, but the goal is to eventually replace lab-based sleep studies where participants are hooked up to various machines overnight. Instead, they could simply put on the pyjama top. The team is still in the process of ensuring that the sensors are accurate for a variety of body shapes. So far, they have tested the shirt on 35 people. They are now developing a full pyjama set that includes pants with built-in pressure detectors that sense the amount of stress on your back. The team presented the work at a meeting of the American Chemical Society this week. More on these topics: sleep