About 19 months ago, a brain-computer interface (BCI) designed at the University of Pittsburgh (Pitt), Pennsylvania, allowed a woman with quadriplegia, Jan Scheuermann, to control a robotic arm with her thoughts. Now, a bioengineer at Pitt has been awarded a five-year, $2.9 million grant from the National Institutes of Health to advance the technology of BCIs, which is poised to help other patients with quadriplegia or amputated limbs. Xinyan “Tracy” Cui, PhD, an associate professor of bioengineering and the grant’s primary investigator, will focus on the microelectrode arrays-the brain implants that act as the interface connecting the brain to the machine or device that performs the function. Research has shown that the microelectrode arrays can cause an inflammatory response in the brain and cause damage to neurons, which weakens the link. The harm to the patient isn’t significant, but poorer recordings of neural impulses can limit the functionality of the technology. Cui will explore ways to coat the microelectrodes with biological molecules to better maintain the connection between the brain implants and computers, and perhaps strengthen that connection.
Scheuermann, who has quadriplegia, brings a chocolate bar to her mouth using a robot arm she is guiding with her thoughts. Researcher Elke Brown, MD, watches in the background. Photograph courtesy of University of Pittsburgh Medical Center Rehabilitation Institute.
“It’s a common trend to see the amplitude of the recorded signal go down, and it becomes lost in the noise,” Cui said. “After a year, we lose half the channels. What we hope to do is camouflage [the microelectrode needles] with biochemicals that can escape the immune surveillance response and protect neurons around the electrodes.”
Andrew Schwartz, PhD, a professor of neurobiology at Pitt, is serving as a co-investigator on Cui’s team. “We did one array, and we had spectacular results,” said Schwartz. “We had very nice recordings with large signals, and they lasted longer than what we would normally see.” According to Schwartz, the initial experiments have shown that the coating extends the viability of neural recording via microelectrode arrays by about six months beyond what is now a nine- to 12-month window. Schwartz is leading a study of the robotic arm technology that was demonstrated by Scheuermann in December 2012.
One target of Cui’s research is a cell adhesion molecule called L1, which has shown positive results in animal models. Cui and her research team will monitor the function of L1 and other tested molecules in a living animal using a new microscopy technique. “In vivo imaging will allow us to see which neurons are firing and which are not active and, therefore, not being recorded,” she said.
Editor’s note: This story was adapted from materials provided by the University of Pittsburgh.
