A team of US researchers has developed a smart pajama that performs an unobtrusive and continuous monitoring of heartbeat, breathing and sleep. The researchers presented their results Monday at the American Chemical Society (ACS). According to a report published on the societys website, the new pajama developed by researchers at the University of Massachusetts, could give ordinary people, as well as clinicians, useful information to help improve sleep patterns, throughout the embedded self-powered sensors. The report explains that the pajama has five discrete textile patches with sensors in them. The patches are interconnected using silver-plated nylon threads shielded in cotton. The wires from each patch end up at a button-sized printed circuit board placed at the same location as a pajama button. Data are wirelessly sent to a receiver using a small Bluetooth transmitter that is part of the circuitry in the button. The garment includes two types of self-powered sensors: four of the patches are piezoelectric that detect constant pressures, such as that of a bed against a persons body; the provided data can be used to determine sleeping posture. The fifth type is a triboelectric patch that detects quick changes in pressure, such as the physical pumping of the heart, which provides information on heart and breathing rates. Trisha Andrew, who led the team that developed the pajama, said in the report: "Our smart pajamas overcame numerous technical challenges. We had to integrate sensing elements and portable power sources into everyday garments, while maintaining the weight and comfort." According to Andrew, the key to the smart pajamas is a process called reactive vapor deposition that allows preserving the embedded sensors while washing the pajama. Andrews team has tested the garment on volunteers and validated the readings from the sensors independently. They also have applied for patents on it. After Andrew partners with a manufacturer, she estimates the product could be on the market within two years for $100-$200.