Many people who exercise like to keep an eye on their heart rate for several reasons. Typically this means they have to wear a smartwatch or a chest strap. However, researchers at Rice University have developed a smart shirt to monitor the heart rate without needing any type of wearable device. Researchers developed a shirt using conductive carbon nanotube thread woven into standard apparel.
The thread was sewn into what appears to be a regular off-the-rack athletic shirt and allows the monitoring of heart rate and continuous echocardiogram of the wearer. The carbon nanotube fibers used in the shirt are as conductive as traditional metal wires but can be washed. In addition, flexible carbon nanotube fibers are more comfortable than metallic wires and less likely to break when the body is in motion.
Another major benefit of the smart shirt is that it was better at gathering data than a standard chest strap monitor when taking live measurements during the experiment. The shirt was also compatible with commercially available medical monitors and delivered slightly better EKG results.
Researchers note the shirt has to be designed to be snug against the chest for accurate readings. The team plans to continue developing their smart shirt and, in future studies, will use more carbon nanotube threads to increase the contact area with the skin. One major upside to this smart shirt developed at Rice is that it is still machine washable.
The carbon nanotube thread they developed is also easily integrated into fabrics using conventional sewing methods. The conductive thread is stitched into the shirt’s fabric using a zigzag pattern allowing it to stretch without breaking. The thread also connects to electronics, such as Bluetooth transmitters, for sending the data wirelessly to a smartphone.