A team of materials science engineers from the University of Illinois and neurosurgeons from the Washington University School of Medicine have developed a type of wireless brain sensor that can monitor intracranial pressure and temperature, then dissolve and be absorbed by the body. This can make additional surgeries to remove these pressure sensors unnecessary.

The Sensor Material

The sensors consist of polylactic-co-glycolic acid (PLGA) and silicone, and are capable of transmitting accurate pressure and temperature readings, as well as other information.

PLGA is a copolymer that is both biodegradable and biocompatible. Itwill dissolve in the body by means of hydrolysis, reducing the sensor materials to lactic acid and glycolic acid. These two acids are natural by-products of the body’s metabolic pathway.

The small sensor connects to an embeddable wireless transmitter that lies on top of the skull. (Image courtesy of John A. Rogers.)

Electrical insulation of the sensor is achieved with a combination of silicone, and a polymer of silicon, oxygen, carbon, and hydrogen.

Testing the dissolubility began with saline baths in research labs, and later moved on to testing in laboratory rat brains. In the saline bath, the sensors dissolved after a few days. In the rat brains, the team confirmed the accuracy of information being collected.

The next step will be to test in human patients.

Challenges Solved, Sensor Dissolved

The researchers believe that implanting these sensors will simplify the process of monitoring the brain after serious injury.; Immune responses triggered in patients is one problem the sensors can potentially overcome. Because they dissolve slowly in the body the risk of infection, chronic inflammation, or erosion through skin at the implantation sight will decrease.

Additional complications are can be avoided by eliminating the need for additional surgeries to remove implants.

The wireless, dissolvable brain sensors are smaller than the tip of a pencil. (Image courtesy of Washington University School of Medicine.)

The research team is also working to address the issue of size and scale. With the sensor measurements established, sensors can intimately connect with organs or brain tissue in several different areas, if required. With wireless connectivity, the necessary information is recorded and then the sensor dissolves.

For cases where patients have experienced severe brain damage, these sensors can aid with operational procedures by closely and accurately monitoring how the brain is responding. The sensor data can also shed light on more severe problems and enable faster response, potentially preventing additional complications or damage.

The Future of Medical Sensing

With approximately 50,000 yearly deaths in the US from brain injury, doctors need accurate measures of intracranial pressure and temperature to respond appropriately. Unfortunately, available equipment such as brain scans cannot provide estimates for crucial information.

Because these sensors can provide accurate pressure readings, they may also have future uses in many other areas of clinical care.

To learn more about these sensors, check out the University of Illinois Material Science and Engineering Department.