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Scientists have developed a wireless device that can stimulate the brain with electric current, potentially delivering fine-tuned treatments to patients with diseases like epilepsy and Parkinson's.
The neurostimulator, named the WAND, works like a "pacemaker for the brain," monitoring the brain's electrical activity and delivering electrical stimulation if it detects something amiss, said researchers at the University of California, Berkeley in the US.
These devices can be extremely effective at preventing debilitating tremors or seizures in patients with a variety of neurological conditions, according to the study published in the journal Nature Biomedical Engineering.
However, the electrical signatures that precede a seizure or tremor can be extremely subtle, and the frequency and strength of electrical stimulation required to prevent them is equally touchy.
It can take years of small adjustments by doctors before the devices provide optimal treatment. WAND, which stands for wireless artifact-free neuromodulation device, is both wireless and autonomous, meaning that once it learns to recognise the signs of tremor or seizure, it can adjust the stimulation parameters on its own to prevent the unwanted movements.
Since it is closed-loop -- meaning it can stimulate and record simultaneously -- the device can adjust these parameters in real-time.
"The process of finding the right therapy for a patient is extremely costly and can take years," said Rikky Muller, assistant professor at University of California, Berkeley.
"Significant reduction in both cost and duration can potentially lead to greatly improved outcomes and accessibility," Muller said.
"We want to enable the device to figure out what is the best way to stimulate for a given patient to give the best outcomes. And you can only do that by listening and recording the neural signatures," he said.
WAND 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 the device, the team used WAND to recognise and delay specific arm movements in rhesus macaques.
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, researchers said.
