A team of researchers at the University of California, Berkeley, has developed a novel neurostimulator that can listen to and stimulate electric current in the brain at the same time, potentially delivering fine-tuned treatments to patients with diseases like epilepsy and Parkinson’s. Dubbed WAND (wireless artifact-free neuromodulation device), the device is both wireless and autonomous, meaning that once it learns to recognize the signs of tremor or seizure, it can adjust the stimulation parameters on its own to prevent the unwanted movements.
Simultaneously stimulating and recording electrical signals in the brain is much like trying to see small ripples in a pond while also splashing your feet — the electrical signals from the brain are overwhelmed by the large pulses of electricity delivered by the stimulation.
Currently, deep brain stimulators either stop recording while delivering the electrical stimulation, or record at a different part of the brain from where the stimulation is applied — essentially measuring the small ripples at a different point in the pond from the splashing.
“In order to deliver closed-loop stimulation-based therapies, which is a big goal for people treating Parkinson’s and epilepsy and a variety of neurological disorders, it is very important to both perform neural recordings and stimulation simultaneously, which currently no single commercial device does,” said team member Dr. Samantha Santacruz.
The WAND device can record electrical activity over 128 channels, or from 128 points in the brain, compared to eight channels in other closed-loop systems.
To demonstrate their device, the scientists used WAND to recognize and delay specific arm movements in rhesus macaques.
The subjects were taught to use a joystick to move a cursor to a specific location.
After a training period, WAND was capable of detecting the neural signatures that arose as the subjects prepared to perform the motion, and then deliver electrical stimulation that delayed the motion.
“While delaying reaction time is something that has been demonstrated before, this is, to our knowledge, the first time that it has been demonstrated in a closed-loop system based on a neurological recording only,” said team leader Dr. Rikky Muller.
“In the future we aim to incorporate learning into our closed-loop platform to build intelligent devices that can figure out how to best treat you, and remove the doctor from having to constantly intervene in this process.”
The device is described in a paper published recently in the journal Nature Biomedical Engineering.