Wireless Pressure Sensor Could Enable Touch-Sensitive Prosthetics

By Chuck Seegert, Ph.D.

A new wireless technology may take pressure sensing to a new level in prostheses and intracranial pressure monitoring. The interesting technology from Stanford University researchers uses radio frequency technology to sense at a distance.

When a patient sustains a traumatic injury to the brain, the organ can swell, leading to catastrophic consequences if not treated. One method of monitoring this swelling is through intracranial pressure sensors, which are devices that pass through the skull and are generally attached to monitors with leads. While this method works, the lead that extends from the patient is a risk that can be infected. Additionally, the lead may be yanked out, causing significant damage to the patient.

To remedy this, Stanford University engineers have developed a wireless pressure sensor, according to a recent press release. The team believes that this device is broadly applicable to many scenarios.

“The device we invented here is extremely easy to manufacture and consumes no energy until readings are being made,” said chemical engineering professor Zhenan Bao, in the press release. “In the short term we hope to use devices like this to track packages and monitor health conditions. In the longer run we dream of using this technology to create touch-sensitive lining for prosthetic devices.”

Proof of concept for the technology was tested in a mouse intracranial pressure model using sensors that were 2.5 mm x 2.5 mm x 0.1 mm, according to a study published by the team in Nature Communications. This is not the lowest size limit, however, as sensors as small as 1.0 mm x 1.0 mm x 0.1 mm are possible with the technology.

This capability opens many doors for the sensors, which are basically small sandwiches of copper layers with a thin rubbery material in between. Reading the device involves beaming radio waves to it and analyzing the return.

“Our team is now considering how to incorporate this device into a catheter that could siphon out cerebral spinal fluid whenever there is an increase in ICP,” said Victor Tse, a neurosurgeon and consulting associate professor at Stanford School of Medicine who was involved with the study, according to the press release.

Enabling a prosthetics with a sense of touch is a high level goal for many research teams, though the technology is currently in its infancy. Recently in an unprecedented advance, researchers unveiled a robotic prosthesis that can send the patient touch sensations through neural connections.

Image Credit: Stanford University