WASHINGTON (AP) _ It's complicated and carries a hefty pricetag, but the federally approved iBOT wheelchair promises to give some of the nation's 2 million wheelchair users new freedom of movement, even allowing them to climb stairs.
The Food and Drug Administration on Wednesday authorized the sale of the iBOT, which uses sensors and gyroscopes to climb up and down stairs. It also shifts into four-wheel drive to navigate grassy hills and can lift its occupant to standing height.
Doctors have called the technology potentially revolutionary and the FDA termed it a breakthrough, but one so complex that, unlike other wheelchairs, it will require a doctor's prescription and special training before patients can buy an iBOT.
The iBOT will cost $29,000, less than some top-of-the-line models for the severely impaired but far more than basic wheelchairs. The maker, Johnson & Johnson subsidiary Independence Technology, is negotiating with Medicare and other insurers to pay for the wheelchair, but could not say Wednesday if that is likely.
Sales will begin by year's end, a J&J spokesman said.
Dean Kamen, the man who invented the Segway scooter, created the iBOT and licensed it to Johnson & Johnson. He says he built it not just for the stair-climbing ability but also the extra elevation because wheelchair users had told him they longed to carry on eye-level conversations with people standing nearby, and to be able to reach top grocery shelves by themselves.
Wheelchairs have become increasingly sophisticated. Some raise a user a few inches to be able to reach high objects. More agile models are specially designed for zipping around basketball or tennis courts. And in the early 1990s, the FDA approved one model solely for stair-climbing, but it never became popular because it did not provide more routine transport, said Robert DeLuca, the FDA scientist who led the iBOT evaluation.
The iBOT, in contrast, is an all-purpose wheelchair that also climbs stairs, he said.
``We think this is something that can really benefit patients,'' DeLuca said. ``It offers many advantages to anything else we've ever seen.''
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. The user leans forward or backward to direct the chair to climb up or down as the gyroscopes sense and adjust to the person's center of gravity.
The iBOT is not an option for all wheelchair users. People must have the use of at least one arm to operate its controls. They must hold onto a stair rail to help guide the iBOT, although there is a feature that allows someone else to hold onto the chair's back and assist the more severely disabled on stairs.
So far, it is not built for children or for people who weigh more than 250 pounds.
To prove iBOT works, 18 wheelchair users test-drove it for two weeks. Scientists compared maneuverability in the iBOT with users' regular wheelchairs in everyday situations and in special road tests.
Twelve patients could navigate stairs alone with the iBOT, while the rest used an assistant. In regular wheelchairs, one patient could bump his way down stairs, but no one could go up a single step.
Three study participants fell out of the iBOT and two fell out of their own wheelchairs _ none on stairs and none was seriously injured _ suggesting the iBOT was as safe as today's technology, FDA concluded.
But the iBOT is complex enough that the wrong person using it could get hurt or injure bystanders, so Independence Technology set up an FDA-approved program to strictly control sales.
Doctors and rehabilitation therapists must be licensed to prescribe the iBOT. They would administer tests to potential users to ensure they are physically capable of handling the machine and have the right judgment skills to discern obstacles, such as which hills are too steep to try climbing.