Armed with a $2,5 million grant they received this year from the National Institutes of Health, University of Florida researchers from the College of Medicine, the College of Engineering and the McKnight Brain Institute have teamed up to create a "neuroprosthetic" chip designed to be implanted in the brain. They are currently studying the concept in rats but are aiming to develop a prototype of the device within the next four years that could be tested in people.
The initial goal is to correct conditions such as paralysis or epilepsy. "We really feel like if we can do this, we'll have the technology to offer new options for patients", stated Justin Sanchez, director of the University of Florida Neuroprosthetics Research Group and an assistant professor of paediatric neurology, neuroscience and biomedical engineering. "There's kind of a revolution going on right now in the neurosciences and biomedical engineering. People are trying to take engineering approaches for directly interfacing with the brain. The hope is we can cure more immediately a variety of diseases."
Researchers have been able to decode brain activity for years using electro-encephalography. Referred to commonly as an EEG, this technology involves placing a sensor-wired net over the head to measure brain activity through the scalp. But the technology wasn't quite sensitive enough to allow researchers to decode brain signals as precisely as needed, according to Justin Sanchez. Now researchers are focusing on decoding signals from electrodes placed directly into the brain tissue using wires the width of a strand of hair.
"Scientists have realized that by going inside the brain we can capture so much more information, we can have much more resolution", Justin Sanchez stated. The chip the University of Florida researchers are seeking to develop would be implanted directly into the brain tissue, where it could gather data from signals, decode them and stimulate the brain in a self-contained package without wires. In the interim, the University of Florida researchers are studying implantable devices in rats and are evaluating an intermediate form of the technology - placing electrodes on the surface of the brain - in people.
The University of Florida researchers have developed new techniques using surface electrodes to access signals almost as precisely as they could with sensors implanted in the brain, according to findings the researchers published in May in the Journal of Neuroscience Methods. Developing these techniques is a big step forward in understanding how to best decode a patient's intent from their brain waves and should have broad implications for delivering therapy, according to Justin Sanchez.
To gather data about the brain's sophisticated cues, which vary from person to person, Justin Sanchez studies the brain signals of children with epilepsy who are scheduled to undergo surgery to remove the part of the brain that is causing seizures. These patients often must be monitored for several days to weeks with electrodes placed directly on the brain. Doctors use this to pinpoint the problem area when a child has another seizure.
Because the children already have electrodes in place, Justin Sanchez is able to use the data gathered from them to understand more about the brain's signals in general. The University of Florida researchers are also working on intermediate concepts that could be wearable, like a diabetes pump, according to Justin Sanchez.
"We have intermediate designs that connect to the brain, interpret signals and can wirelessly send commands to devices", he stated. "This is another path of technology we're pursuing."
To create these technologies, Justin Sanchez is in the process of developing a centre for brain-machine interfaces at the University of Florida with faculty from the College of Engineering, including Jose C. Principe; John G. Harris; Toshikazu Nishida; and Rizwan Bashirullah.
But several challenges face researchers in bringing these technologies to patients, according to Dr. Steven J. Schiff, a professor of engineering and neuroscience at the Pennsylvania State University and director of the Penn State Center for Neural Engineering.
For patients with epilepsy, who often have to take several medications or undergo surgery for relief from debilitating seizures, a neuroprosthetic device could be the best form of treatment, according to Dr. Schiff, adding that more work needs to be done to understand the mechanics of what causes diseases such as epilepsy and Parkinson's.
"The challenge is not so much the technology", Dr. Schiff stated. "The challenge is to use that technology wisely." The day may not be too far off when patients can control a prosthetic hand or leg just by thinking about it, according to Justin Sanchez. "It's becoming a reality", Justin Sanchez stated. "We're designing electronics that we can interface with biological systems and we can use that to help people."