Surgical robot takes a cheeky approach to brain surgery

In a new non-invasive method to treat severe epilepsy, researchers have developed a surgical robot that uses an alternative point of entry in brain surgery - through the cheek.
For those most severely affected, treating epilepsy 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.
To address epileptic seizures in a less invasive way, a team of Vanderbilt University engineers developed a robotic device that pokes through the cheek and enters the brain from underneath which avoids having to drill through the skull and is much closer to the target area.

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 Magnetic resonance imaging (MRI) scanner.
The business 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.
Using compressed air, a robotic platform controllably steers and advances the needle segments a millimetre at a time.

According to David Comber, the graduate student in mechanical engineering who did much of the design work, 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, millimetre steps so the surgeon can track its position by taking successive MRI scans.
According to Associate Professor of Mechanical Engineering 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.
"To have a system with a curved needle and unlimited access would make surgeries minimally invasive. We could do a dramatic surgery with nothing more than a needle stick to the cheek," Professor of Neurological Surgery Joseph Neimat said.
The engineers have designed the system so that much of it can be made using 3-D printing in order to keep the price low.