Turning Sutures Into Sensors

A number of wearable and implantable sensors are now used to collect medical information from patients. It's possible, for example to wear devices that monitor body temperature, heart rate, steps taken, etc. A limitation of most wearable sensors is that they must lie relatively flat against the body. More importantly, none are very effective at monitoring the complex chemical changes that can take place within the body.

A breakthrough technology of the future may be to create "smart thread" - specialized types of sutures that could be used as sensors. Sutures are flexible, cheap, and easily implanted into the skin or even into organs. Researchers at Tufts University are studying how to coat sutures with conductive materials so that they might be used to monitor mechanical activity or chemical activity. Coating stretchable suture material with nanotubes and silicone causes the thread's resistance to change when they are stretched, so that by passing a small amount of current through the thread, sutures could be used to measure physical strain. By taking advantage of the wicking properties of some fibers (most notably cotton), sutures could be used to monitor the complex biochemistry of interstitial fluid in real time. Such sutures might be particularly useful in monitoring the progress of wound healing, where local conditions (pH, electrolytes, and glucose, for example) might be quite different from conditions elsewhere in the body.

So far, most of these ideas are just that: ideas. But the Tufts researchers are laying the groundwork with experiments in rats and in animal tissues such as chicken skin. Don't be surprised if someday your physician suggests using a smart suture to monitor some aspect of your health.