Features

By the end of the semester, the universal wheelchair team had made considerable progress. The students added a number of safety features to the wheelchair, such as tilt control, edge control, proximity control and an electrical ground to protect the occupant from any stray biopotential electrical currents. Katie Schwarzenberg '07 and Matthew Jamrog '07 succeeded at getting the chair to move in different directions by voice command through the use of a voice-recognition computer chip.

Sandler and partner Lucas Liimatainen '07 worked on the eye-movement control system. The front of the eye acts as a positive pole, explains Sandler, and the back is negative. Electrodes attached to the face near the eyes can detect changes in voltage as the eyes rotate. The students used an electro-oculograph to measure the changes and built a circuit to translate them into the on/off signals needed to move the wheelchair with a joystick. They succeeded in getting the chair to turn left by this method.

Christopher Bancroft '07 and Christopher Sabato '07 worked on the most elegant and challenging goal: thought control. The brain waves known as µ (mu) waves "are almost like idle waves—they're generated in the motor cortex when you're relaxed," says Bancroft. "When the left side of the body is relaxed, they're generated in the right hemisphere, and vice versa." Moving a muscle—or even intending to move a muscle—stops the µ waves. So theoretically this method could be used by someone like Luke Samuelson, who can intend to move his arm, even if he can't actually move it. These waves, too, can be captured and converted to on/off signals—UNH engineers have already demonstrated how µ waves can be harnessed in place of a mouse to move the cursor on a computer screen.

The brain waves proved difficult to capture, especially since none of the students offered to shave his or her head for the sake of science. Lacking the perfect hairless scalp for attaching electrodes, the team made do with a bathing cap coated with gel. LaCourse believes that more advanced equipment, including touchless electrodes and a dynamic filter, could help this year's team separate the extremely weak µ waves—at a mere 10^-6 volts, they must be amplified 100,000 times—from background noise.

For Samuelson, who now knows Morse code but can't yet "send" a message, difficulties with technology are far from academic. Tibbany Black witnessed his determination last spring when she helped him use Rappa and Minuti's finger-switch and black-box trainer: "I've seen him keep practicing until sweat is pouring down his face, and then he'll continue to practice." Still, the balance between frustration and motivation can easily tip the wrong way, and over the summer, she and his caregivers had to think outside the little black box, at least temporarily, moving away from the dot-dash approach in an effort get any muscle to fire consistently. So he practiced with a wrist-activated laser beam switch and something that motivates millions: a computer game, albeit a simple bowling game designed to record his timing.

This fall, Black expects to work more intensively with Samuelson at the UNH Speech-Language-Hearing Center as part of her required clinical practicum. It didn't take long to discover that "everything is communication" for someone like Samuelson, and she could easily interpret his expressions. Still, a conversation with him often resembles a game of 20 Questions, and she envisions a time when he might finally be able to use language to reveal his jokester personality and perhaps even approach young women with some clever pickup lines.

Deb Hiney, a speech language pathologist who has worked with Samuelson since he was 3, believes he will persevere. As to what he has gained so far, she says, "I believe he has learned what he has always known: that he is unique, and it will take a whole team of folks to figure out the best way for the outside world to get to know him." ~

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