Nan Davis Takes One Small Step for Herself That May Give Hope to Other Paraplegics
06/27/1983 at 01:00 AM EDT
The last time Nan Davis walked in public was five years ago at her high school graduation. Late that night she was paralyzed from the rib cage down in a car crash. But two weeks ago Nan again took a few tentative steps, at her graduation from Ohio's Wright State University. She did it with the help of two strong helpers at her elbows and a purse-size computer that fed precisely timed impulses to 24 electrodes taped to her legs. The firing of the electrodes caused muscles to contract, and she was able to place one foot jerkily in front of the other. Even though the setup malfunctioned as she turned too quickly at the podium—a sensor came loose on her left leg, causing that leg to go limp—her 10-foot trip to the podium was a remarkable achievement. She received a B.S. degree in elementary education and a standing ovation from the crowd of 80,000. Jerry Petrofsky, 35, the Wright State biomedical engineering professor who developed the experimental device that guides Nan's legs, is both cautious and pleased about her progress. "It is an early research project," says Petrofsky. "But I did not think we were going to be where we are for years."
Nan began working with Petrofsky, who had done earlier work with muscle stimulation in animals, a year ago. Their first achievement was to stimulate her legs electronically to lift weights, thus strengthening her atrophied muscles. Last November, with her weight partially supported by a parachute harness suspended from the ceiling, Nan took her first electronic step. Petrofsky's next goal was to program his new miniature computerized stimulator so Nan could walk with canes. The big problem is still balance: The computer has a hard time calculating the position of Nan's body. Says Petrofsky, "When you are working with canes or free-walking, you can't afford any errors. One mistake, a broken leg."
In addition to improving Nan's muscle tone and offering the tantalizing promise of increased mobility, electronic stimulation has also made her something of a celebrity. She has spoken at medical conventions from Las Vegas to Toronto, and in April she appeared before a House committee on funding biomedical research. Soon she will audition to play herself in a CBS-TV docudrama on Petrofsky's life.
The next step for Petrofsky, an inveterate tinkerer who met his wife, Cheryl, 36, through a computer dating service, is broader experimentation. Some critics have suggested that problems of balance and control will be insurmountable. Also, Petrofsky's devices cannot help those who have been crippled so long that their muscles cannot be built up again. But Petrofsky sees the field as eminently worthy of exploration. He hopes eventually to transfer his program onto a computer chip that could be implanted in a patient's lower torso and controlled by the patient's back and chest muscles. "I think it would be criminal to sit here with all the technology that has come out of the space program and not try to apply it," says Petrofsky. "All that's missing is the experiments that hook up the technology to the human body."
Nan Davis is helping to bridge that gap. "Adjusting to my injuries was hard at first," says Nan, a former high school sprinter. "But I was an athlete, and I have the quality of being compet itive, and that helps in the fight to over come my injury." She pauses to reflect. "You can live with your injury if you have to. But there's no reason you have to accept it."