Voice-Controlled Wheelchair One Product of Bioengineering Research

Posted: March 15, 2010 at 1:04 am, Last Updated: March 15, 2010 at 8:16 am

By Marjorie Musick

Nathalie Peixoto. Creative Services photo

What happens when you put a computer inside a human brain? That is a question Mason bioengineer Nathalia Peixoto is trying to answer.

In a lab filled with equipment straight out of the space age, such as remote-control robots, a voice-activated wheelchair and a glove that interprets sign language, Peixoto is perfecting the art of mixing biology with engineering to help improve people’s lives.

Peixoto has dedicated her career to combining biological, physical and mathematical knowledge to solve problems in medicine.

After postdoctoral work at Stanford University, Peixoto worked for two years at Mason’s Krasnow Institute for Advanced Study, focusing on seizure control with low-frequency electric fields.

When the Volgenau School of Information Technology and Engineering began looking for a faculty member with expertise in bioengineering, Peixoto fit the bill. Now an assistant professor of bioengineering in the Volgenau School and director of the Neural Engineering Lab, she has labs in Krasnow and the new Long and Kimmy Nguyen Engineering Building.

A significant focus of her research is on implantable electrodes and interfaces between electronics and tissue. Electrodes, microchips and prosthetic devices are a few of the technologies Peixoto incorporates into her work.

By implanting devices that send out electrical currents in the brain, Peixoto hopes to combat such devastating conditions as epilepsy, Alzheimer’s disease and Parkinson’s disease.

“We study what happens as soon as you put something in the brain for stimulation and recording, and how the body reacts to that,” Peixoto says. “We want to show that it’s a symbiotic relationship, a friendly relationship between the wire and the body.”

Hybrid systems comprising cell cultures and electronics also have potential health benefits for humans. According to Peixoto, brain cells removed from snails or mice and placed on Petri dishes attached to computer chips can thrive, learn and retain information.

Peixoto and her students are testing a voice-activated wheelchair. Creative Services photo

The chip sends out pulses, or a “Morse code,” to the cell culture and vice versa, establishing a two-way communication between the cell culture and the computer chip.

“The cell cultures are sitting on top of a microchip that is feeding into the cultures as if they were a brain feeding [information] into a body,” Peixoto says. “Eventually, you can design experiments where you transmit two patterns and see which one the cell culture picks, which would be the one it learned. So it’s extremely simple [on one level], and yet it’s very complicated to implement.”

Peixoto notes that the health implications of studying the interface of cell cultures and computers range from protecting soldiers from biological warfare on the battlefield to reducing inflammation from orthopedic implants for bone injuries and implants for treating depression, Parkinson’s disease or epilepsy.

Peixoto also is working with prosthetic devices and assistive technology to improve the quality of life for those with disabilities. One such device is a voice-controlled wheelchair. The chair was donated by a company that makes custom wheelchairs and was modified by Peixoto’s students to interface with a computer.

“The basic idea is that you talk. You say ‘forward’ and ‘backward’, and the chair goes back and forth,” says Peixoto. To control the chair’s speed, they added an accelerometer that the user can control by humming, something almost everyone can do.

“We hope that once the chair is patented and on the market, it will help a lot of people,” says Peixoto.

The kind of work that Peixoto and her colleagues are doing requires a great deal of creativity, ingenuity and, most important, collaboration.

“The idea is that the bioengineers build a bridge between here and, in my case, Krasnow, because of my interest in neuroscience,” she says. “In other cases, faculty and students work with psychology, biology or molecular science.”

Contingent upon approval by the Commonwealth of Virginia, a bachelor of science degree in bioengineering will be offered beginning in fall 2010. The degree will be administered by the Department of Electrical and Computer Engineering in the Volgenau School and have a multidisciplinary faculty.

This article originally appeared in a slightly different form in Mason Research 2010.

Write to mediarel at gazette@gmu.edu