For a percentage of patients with epilepsy, the drugs are less effective at controlling seizures, or they do not work at all. For these patients, there is another option: brain surgery. This is usually a deeply invasive procedure, in which the section of the patient’s brain is either removed, stimulated, or disconnected; recovery may take up to three months thereafter.
A robot five years in the making by researchers at Vanderbilt University can be online to make surgery less time-consuming, less invasive, and with a shorter recovery time.
The area of the brain involved in epileptic seizures is the seahorse, which is located in the lower regions of the brain. The surgical robot developed by mechanical engineering graduate student David Comber and associate professor of mechanical engineering Eric Barth enters the brain from below through the patient’s cheek, carefully negotiating spaces in the bone. It is not only a shorter route, it also avoids piercing the skull.
The functional prototype involved the development of a shape memory alloy needle – that is, an alloy that can remember its original shape and return to it when heated after being deformed – that can work along a curved path. The robot also needed to be able to operate from inside an MRI machine, which creates a strong magnetic field.
The resulting needle is created from nickel titanium, also known as nitinol, a shape memory and non-ferromagnetic alloy, which makes it compatible with MRI machines. The 1.14mm needle works like a mechanical pencil, made up of a series of concentric tubes, some of which are curved so that the tip follows a curved path to the brain.
It’s inserted in tiny millimeter steps that allow the surgeon to track his position by performing MRIs every step of the way, and its accuracy, the team says, is better than 1.18mm.
“I have worked a lot in my career on controlling pneumatic systems,” said Barth. “We knew we had this ability to have a robot in the MRI scanner, doing something in a way that other robots couldn’t. Then we thought, ‘What can we do that would have the greatest impact?
At the same time, their colleague, Associate Professor of Mechanical Engineering Robert Webster, had developed a system of steerable surgical needles – which combined perfectly with the idea.
The team also collaborated with Associate Professor of Neurological Surgery Joseph Neimat, who explained that the through-cheek method was already in use for some procedures – implanting electrodes to track brain activity and identify sites of brain activity. epileptic seizures. However, the needles used for this are straight and therefore cannot reach the region of the brain to perform surgery.
“The systems we have now that allow us to introduce probes into the brain – they process straight lines and are only guided manually,” Neimat said. “Having a system with a curved needle and unrestricted access would make surgeries minimally invasive. We could do dramatic surgery with nothing more than a needle stuck to the cheek.”
The next step in the development of the robot will be to test it on corpses. Associate Professor Barth estimates that it could be used in operating rooms within a decade.