Stairs soon may no longer be insurmountable obstacles for some of the nation's 2-million wheelchair users.
The first wheelchair that can climb stairs _ plus shift into four-wheel drive to scoot up a grassy hill and even elevate its occupant for eye-level conversation _ took a major step toward the market Wednesday, as advisers to the Food and Drug Administration unanimously recommended it be approved for sale.
But the panel backed a few limitations on the Independence iBOT 3000 Mobility System _ which uses sensors and gyroscopes to balance on two wheels and navigate stairs _ including that it sell only with a doctor's prescription and strict training to ensure users can drive it safely.
The FDA isn't bound by its advisers' recommendations, but usually follows them. It granted the iBOT a special fast-track review reserved for important new medical technology, meaning a decision could come in a few months.
How does it climb? Most wheelchairs have two big back wheels and two smaller front wheels. The iBOT has four wheels the same size that rotate up and over one another to go up and down steps.
Well-known inventor Dean Kamen created the iBOT and says wheelchair users tell him another feature is as appealing: The chair lifts onto two wheels so its occupant, although still sitting, is elevated enough to reach high bookshelves and carry on eye-level conversations with people who are standing.
"One reason I built it was to let people stand up," said Kamen, who licensed the iBOT to Johnson & Johnson. "We treat a lot of adults like children because they can't stand up."
"I wanted to take it home and keep it," said Karl Barnard of Tilton, N.H., who tested the iBOT in a study required by the FDA, which regulates wheelchair safety.
In the iBOT, he rose to the height of a 6-foot-tall person to grocery shop without help. Barnard, who lost use of his legs 25 years ago, has no stairs in his home but was impressed with the four-wheel drive that let him roll up hills and through gravel on his farm, places his manual wheelchair can't go.
But because of a predicted $29,000 price tag, Barnard, 46, calls it "more a luxury item" that he probably wouldn't spring for until he's too old to push his manual wheelchair easily.
While several FDA advisers called the chair potentially revolutionary, they also cautioned that it's not for everyone.
Patients must have the use of at least one arm to operate the chair, moving it with a joystick and other controls, and so far it's built only for large teenagers and adults.
Also, it requires some exertion: Users lean forward or backward, directing the chair to climb up or down as it senses and adjusts to the person's center of gravity. They must hold onto a stair rail to help guide it, although there is a feature that allows someone else to hold onto the chair back and assist the more severely disabled on stairs.
Picking the right patient is crucial for safe use. A person must not only be physically capable of handling the iBOT, but must have the judgment to avoid obstacles such as hills that are too steep to try climbing without risking serious falls, said Dr. Steve Stiens, a University of Washington rehabilitation specialist who uses a wheelchair himself.
Sales will be strictly controlled, responded manufacturer Independence Technology, a Johnson & Johnson subsidiary. Doctors and rehabilitation therapists must undergo special training to prescribe the iBOT, and potential users would have to pass a test proving they can drive it safely before taking it home.
To prove iBOT works, 20 wheelchair users test-drove it for two weeks, allowing scientists to compare maneuverability, falls or other problems with their regular wheelchairs. They also took a road test, scooting up hills and over bumpy sidewalks, crossing curbs, reaching shelves and climbing stairs.
The patients performed most of the challenges more easily with the iBOT, said the study leader, Dr. Heikki Uustal of New Jersey's Johnson Rehabilitation Institute.
Twelve patients could navigate stairs alone with the iBOT, while the rest used an assistant. In regular wheelchairs, two patients could literally bump their way down stairs, but no one could go up a single step.
Three people fell out of the iBOT and two fell out of their own wheelchairs during the study, suggesting the iBOT was as safe as today's technology.
The iBOT's $29,000 tab is less than some top-of-the-line models for the severely impaired, but far more than basic chairs. But Independence Technology president Jean-Luc Butel said the average cost for ramps, elevators and other home modifications for someone unable to walk is $40,000, expenditures largely unnecessary with the iBOT. He is negotiating with Medicare and other insurers to pay for the iBOT.
Upstairs, downstairs for the wheelchair
The Food and Drug Administration reviewed a wheelchair that potentially increases mobility for some of the nation's 2-million wheelchair users. Using a joystick and other controls, its occupant can go up and down stairs and elevate to eye level.
Two sets of wheels rotate up and over one another to go up and down steps while sensors and gyroscopes balance it. The user must lean backward and forward to direct the chair to climb up and down. The chair lifts onto two wheels to raise its occupant to eye level, or to reach an item previously out of range.