Dissolvable Brain Sensor

J. Rogers/University of Illinois

Dissolvable Brain Sensor Could Help Head Injuries by Measuring Swelling - A dissolvable brain sensor that can measure swelling is under development by a neurosurgeon from the Washington University School of Medicine, meaning the body will absorb it when it finishes its job.

The Atlantic reported that the surgeon, Rory Murphy, "deals with brain trauma all the time," as he describes it. "I just took out a bullet from the back of a guy’s head an hour ago," he said during an interview.

Murphy has been working with flexible-electronics expert John Rogers from the University of Illinois, and together they've developed a pressure sensor that's many times smaller than a fingernail, and thinner than the tip of a needle.

The pressure sensor will hopefully one day help treat and prevent the 50,000 annual head injuries that result in death. Bullets, blunt forces, blood clots, and more all cause brain swelling, which can be deadly if not monitored.

Current pressure sensors must be implanted and eventually removed, but Murphy hopes to eliminate the second step altogether.

The pressure sensor he developed "consists of a membrane made from PLGA, a polymer regularly used in medical devices, suspended in a frame of silicon and magnesium. The pressure of the surrounding fluid causes the membrane to bend, which changes the electrical resistance of an adjoining silicon sensor. The whole device is then wrapped in a watertight polymer that gradually erodes over a few days, setting the lifetime of the sensor."

"The materials we chose include very small amounts of things like magnesium and silicon, which are recommended parts of the daily diet," said Rogers.

The pair found success with the sensors during tests with rats, and now plan to test their sensors in pigs before moving on to bigger and bigger specimens until they are safe for human clinical tests.

The Guardian U.K. reported that, in the long run, "The researchers say the device can easily be modified in other ways to monitor other important physiological parameters of brain function, such as acidity and the motion of fluids. It could also be used to deliver drugs to the brain, and, with the incorporation of microelectrodes, to stimulate or record neuronal activity."