Researchers from the University of Illinois at Urbana-Champaign and Washington University School of Medicine have created a new class of small, naturally dissolving electronic sensors that could be revolutionary for brain injury treatment and recovery.
Following a traumatic brain injury or brain surgery, it is often crucial to closely monitor the brain for swelling or changes in pressure and temperature. However, doing this is typically a complicated task. Current monitoring technology is clunky and typically requires invasive surgery to both implement and remove once a patient has been cleared. Additionally, the wires restrict patient’s head movement and can hamper physical therapy.
Because this method requires continuous, hard-wired connection to the head, they also put patients at increased risk for allergic reaction, infection, and even hemorrhage.
Noting the numerous risks and complications associated with this method of monitoring, John A. Rogers, professor of materials science and engineering at the University of Illinois, and Wilson Ray, professor of neurological surgery at Washington University School of Medicine set out to create a new type of senor that would do away with external wires and invasive removal surgery.
“If you simply could throw out all the conventional hardware and replace it with very tiny, fully implantable sensors capable of the same function, constructed out of bioresorbable materials in a way that also eliminates or greatly miniaturizes the wires, then you could remove a lot of the risk and achieve better patient outcomes,” Rogers said. “We were able to demonstrate all of these key features in animal models, with a measurement precision that’s just as good as that of conventional devices.”
To achieve making a sensor that could naturally ‘melt’ away in the brain, the new device incorporates dissolvable silicon technology developed by Rogers and colleagues at the University of Illinois. The new sensors are built on incredibly thin sheets of silicon smaller than a grain of rice, and are made to remain functional for a set period of days before dissolving harmlessly.
The sensors are designed to sense clinically relevant pressure levels within the intracranial fluid around the brain, as well as changes in temperature. It then sends this data wirelessly through a tiny transmitter implanted beneath the skin, but outside the skull.
To test the sensors, the team worked with traumatic brain injury experts at Washington University to test the sensors in rats. The team saw the new devices were as accurate, if not more accurate than currently used technology.
Perhaps most promising, the new sensors can also be adapted for postoperative monitoring of othr body systems as well.
“The ultimate strategy is to have a device that you can place in the brain – or in other organs in the body – that is entirely implanted, intimately connected with the organ you want to monitor and can transmit signals wirelessly to provide information on the health of that organ, allowing doctors to intervene if necessary to prevent bigger problems,” said Rory Murphy, a neurosurgeon at Washington University and co-author of the paper. “After the critical period that you actually want to monitor, it will dissolve away and disappear.”
Next, the team hopes to conduct human trials to see if the devices are accurate and non-obtrusive when implanted in a person’s head.