Monday , July 26 2021

"Wireless pacemaker for the brain" for a new treatment of neurological disorders


The new neurostimulator developed by engineers at the University of California, Berkeley, USA, can simultaneously listen and stimulate the electrical current in the brain, which can offer precise treatments for patients with diseases such as epilepsy and Parkinson's disease. The device, called WAND, works as a brain pacemaker, controls the electrical activity of the brain and provides electrical stimulation if it detects that something is wrong.

These devices can be extremely effective in preventing tremors or frail seizures in patients with various neurological conditions. But electrical signatures that precede convulsion or tremor can be extremely subtle, and the frequency and strength of the electrical stimulation needed to prevent them are equally delicate. Doctors can spend years to make minor adjustments before devices provide optimum treatment.

WAND, which means neuromodulation of wireless devices without artifacts, is wireless and autonomic, which means that once you learn to recognize the signs of tremor or convulsion, you can only adjust the stimulation parameters only to prevent unwanted movements. And since it is a closed cycle, which means it can stimulate and record simultaneously, it can adjust these parameters in real time.

"The process of finding the right patient therapy is extremely expensive and can last for years, a significant reduction in costs and duration can lead to much better results and accessibility," says researcher Rikky Muller, assistant professor of engineering. Electrical and Computer Science in Berkeley. "We want the device to find out which is the best way to stimulate a particular patient to get the best results, and he can only do it by listening and recording nerve signatures."


WAND can record electrical activity in 128 channels, or 128 points in the brain, compared to eight channels in other closed circuit systems. To demonstrate the efficiency of the device, the team used WAND to recognize and delay specific hand movements in rhesus macaques. The device is described in an article published on Monday in "Natural Biomedical Engineering".

At the same time, encouraging and capturing electrical signals in the brain is very similar to trying to see small ripples in the pond, and at the same time pushing their feet: electrical signals of the brain are overwhelmed by the great impulses of electricity that stimulate stimulation.

At present, deep brain stimulators stop recording while administering electrical stimulation or recording activity in a different part of the brain from which the stimulation is applied, essentially by measuring small irregularities at a different point in the purgator's pond.

"In order to offer closed-cycle therapy based therapy, which is a great goal for people who treat Parkinson's disease and epilepsy and various neurological disorders, it is very important to simultaneously perform neuronal imaging and stimulation, which currently does not exist no commercial device, "says former associate postgraduate at Berkeley University, Samantha Santakruz, who is now an assistant professor at the University of Texas at Austin.

Researchers at Cortera Neurotechnologies, Inc., led by Rikky Muller, designed Integrated WAND circuits that can record the full signal of both subtle brain waves and strong electrical impulses. This chip design allows WAND to minimize the signal from the electrical impulses, resulting in a clear signal from the brainwaves.

Existing devices are tuned to capture signals only from smaller brain waves and are overloaded with large stimulus impulses, which disables this type of signal reconstruction. "Because we can actually stimulate and record in the same region of the brain, we know exactly what happens when we give the therapy," Muller said.

In collaboration with professor of electrical engineering and computer science, Jan Rabai, the team has built a platform for devices with wireless and indoor computer capabilities that can be programmed for use in a variety of clinical and research applications.

In the experiments carried out by Santacrug, while in UC Berkeley and by professor of electrical engineering and computer science, Jose Carmen, the subjects were taught to use a joystick to move the cursor to a specific location. After the training period, the WAND device was able to detect neural signatures that emerged when subjects were ready to perform the movement, and then provided electrical stimulation that delayed the movement.

"Although the delay in reaction time is something that was previously demonstrated, this is, as far as we know, first demonstrated in a closed circuit system based on neurological recording," Miller points out. In the future, our goal is to include learning in our closed cycle platform to create smart devices that can discover the best way to treat people and prevent the doctor from intervening in this process. "

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