Pressure-sensing implant dissolves when its job is done
When doctors want to monitor conditions such as swelling of the brain, they'll sometimes implant a sensor that emits a readable electrical signal whenever it's subjected to pressure. The problem is, those sensors have to be retrieved from the patient's body afterwards, requiring additional surgery. That may not be the case much longer, though, as scientists have created an implantable pressure sensor that harmlessly biodegrades.
Created by a team at the University of Connecticut, the flexible sensor is made entirely from materials that the US Food and Drug Administration has already deemed safe for use in surgical sutures, bone grafts, and medical implants. It takes the form of two layers of piezoelectric Poly(L-lactide) film, which are sandwiched between molybdenum electrodes and encapsulated in layers of polylactic acid.
When even a slight amount of pressure is applied to it, it emits a small electrical charge. That signal can be detected by a device outside of the body.
It's capable of capturing a wide range of physiological pressures, including those found in the brain, behind the eye, and in the abdomen – the sensitivity of the device can be tweaked by changing the number of layers of Poly(L-lactide) film.
Additionally, in tests performed on mice, there was only minor inflammation after the sensor was implanted, with the surrounding tissue returning to normal after four weeks.
"Medical sensors are often implanted directly into soft tissues and organs," says lead scientist Thanh Duc Nguyen. "Taking them out can cause additional damage. We knew that if we could develop a sensor that didn't require surgery to take it out, that would be really significant."
A paper on the research was recently published in the journal Proceedings of the National Academy of Sciences.
Source: University of Connecticut