Brain surgery through the cheek

From the Winter 2015 edition of Vanderbilt Medicine Magazine

Photo by Laboratory for the Design and Control of Energetic Systems / Vanderbilt

Treating epilepsy often means drilling through the skull deep into the brain to destroy the small area where the seizures originate—invasive, dangerous and with a long recovery period.

Five years ago, a team of Vanderbilt engineers wondered: Is it possible to address epileptic seizures in a less invasive way? They decided it would be.

To do so, however, meant developing a shape-memory alloy needle that can be precisely steered along a curving path and a robotic platform that can operate inside the powerful magnetic field created by an MRI scanner.

The engineers have developed a working prototype, which was unveiled in a live demonstration in fall 2014 at the Fluid Power Innovation and Research Conference in Nashville by David Comber, the graduate student in mechanical engineering who did much of the design work.

At one end of the device is a 1.14 mm nickel-titanium needle that operates like a mechanical pencil, with concentric tubes, some of which are curved, that allow the tip to follow a curved path into the brain. (Unlike many common metals, nickel-titanium is compatible with MRIs). Using compressed air, a robotic platform controllably steers and advances the needle segments a millimeter at a time.

According to Comber, they have measured the accuracy of the system in the lab and found that it is better than 1.18 mm, which is considered sufficient for such an operation. In addition, the needle is inserted in tiny, millimeter steps so the surgeon can track its position by taking successive MRI scans.

According to Eric Barth, who headed the project, the next stage in the surgical robot’s development is testing it with cadavers. He estimates it could be in operating rooms within the next decade.

By David Salisbury and Heidi Hall