Neurosurgeon Rory Murphy worked with engineers in the US to create electronic sensors that are eventually reabsorbed by the brain. The medical graduate from University College Cork is completing his neurosurgical residency at Washington University School of Medicine, where he specialises in brain trauma.
A challenge for surgeons such as Dr Murphy is finding reliable ways of monitoring pressure inside patients’ skulls.
Brain sensors currently used are larger than the tiny sensors he has helped create and must be removed once the patient recovers. The dissolvable pressure sensors are thinner than the tip of a needle and can be left in a patient’s brain to take accurate readings before disappearing.
Dr Murphy worked with John Rogers and his team at the University of Illinois on developing the revolutionary pressure sensor.
The sensor is suspended in a frame of silicon and magnesium and contained in a watertight polymer that gradually erodes over a number of days. The pressure of the surrounding fluid causes the membrane to bend, and that changes the electrical resistance of an adjoining silicon sensor.
Dr Murphy implanted the device in rats and found it as accurate as the best pressure sensors on the market. As well as pressure, the sensors can measure temperature and flow rates.
“This type of bioelectric medicine has great potential in many areas of clinical care,” said Dr Murphy, adding that the ultimate aim is dissolvable sensors that could be placed in the brain or other organs. “And then, after the critical period that you actually want to monitor, it will dissolve away and disappear.”
The device is cost-effective because of the materials used. It did not cause any inflammation or immune response, either before or after it dissolved. Materials like magnesium and silicon are constituents of the daily diet which is why the sensors are completely absorbed into the body when they dissolve.
The team will test the sensors in pigs and complete more studies to show that the devices are safe.
Dr Murphy said clinical trials in humans could take place in three to five years.
An article outlining the sensor’s success has been published in the scientific journal, Nature.