2. Minimally invasive electrode arrays for better epilepsy treatmentMany people with epilepsy don’t respond to respond to medication and instead need surgical resection or ablation. The major challenge is finding the focal point of the epileptic seizure in the brain that needs to be removed, Wehde of Mayo Clinic said at DeviceTalks Minnesota last month.
Surgeons will perform a craniotomy, taking off half of a person’s skull, placing an electrode array on the surface of the brain, wrapping it up and then sending the person with the electrodes to the hospital for days or even weeks until a seizure takes place and the electrodes discover the focal point.
The craniotomy procedure has a fairly high morbidity rate, not to mention a great deal of discomfort. Neurologists at Mayo Clinic wanted to do something different. “They said, ‘What I want to do is create a small burr hole or a keyhole where I can put the electrodes in and just spread them out between the skull and the surface of the brain,’” Wehde said.
Mayo Clinic’s Division of Engineering needed to figure out solutions for both the electrodes and the insertion tool.
They created custom flexible electrodes that could deploy inside the skull. “We’ve got a spin coater which allows us to spin a very thin layer of the substrate, we have a physical vapor deposition system which lets us put down conductive metals, we’ve got a parylene deposition system which lets us do insulators, and we’ve got a femtosecond laser that allows us to do patterning of the various electrodes,” Wehde said.
They started out with 32 conductor electrodes and then went to 128. The Mayo Clinic team is now working on a version with 1,024 electrodes.
When it came to the insertion tool, the Mayo Clinic team 3D-printed prototypes to test on cadavers. They now have a next-generation titanium version of the device that they plan to take into animal trials.