|This is a mockup of a patient in an MRI machine showing|
how the surgical robot can perform epilepsy surgery through
the cheek. (Credit: David Comber, Vanderbilt University)
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. It is invasive,dangerous and with a long recovery period. Researchers have now addressed this problem.
Since the area of the brain involved is the hippocampus, which is located at the bottom of the brain, the researchers could develop a robotic device that pokes through the cheek and enters the brain from underneath. This 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 MRI scanner. The engineers have developed a working prototype, which was unveiled in a live demonstration this week 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.
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 millimeter at a time.
The researchers 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.
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.