A team of physical therapists strapped the robot onto him, one hit a button and with a faint electronic whir, David Ayscue was suddenly 6 feet tall again.

Then Ayscue took a step, and a different future came just a bit closer for him and millions of others who can't walk on their own.

"I guess this is how a baby feels taking its first steps," he said. "I can't describe it. It's just overwhelming."

Ayscue, 56, was learning how to use a new robotic exoskeleton called an Ekso. The North Carolina Department of Transportation maintenance worker suffered a spinal cord injury on the job while cutting up a dead tree 2 1/2 years ago.

The device that he was wearing is an outgrowth of Pentagon-sponsored research into robotic devices to help soldiers carry heavy loads. The civilian model was developed to help people who use wheelchairs to stand and walk again.

WakeMed's rehabilitation hospital in Raleigh is the first in the Carolinas and one of just 16 in the country to get the device since it went on the market in February, said Eythor Bender, CEO of Ekso Bionics, based near San Francisco.

For now, the Ekso is an aid for physical therapy clinics with the help of therapists trained in its use, but the company is working on a sleeker, cheaper model for home use, which it hopes to begin selling in two years.

Initially, WakeMed is using it on patients with spinal cord injuries who can't walk on their own, but it plans to eventually use it on other kinds of cases, such as stroke patients.

Elsewhere, the device is already used for patients with other health problems, including multiple sclerosis, amyotrophic lateral sclerosis (Lou Gehrig's Disease) and traumatic brain injuries.

For patients who spend significant amounts of time in wheelchairs, being able to spend at least a little time in the device regularly is likely

to offer improvements in a host of functions, such as circulation, respiration and digestion, said Cathy Smith, director of outpatient rehabilitation at WakeMed.

It may help those with partial spinal cord injuries regain some function more easily.

Less sophisticated devices are in place at several Minnesota treatment centers. Sister Kenny Rehabilitation Institute in Minneapolis, uses a Locomat robotic system that moves a patient's legs on a treadmill while holding the person upright.

Another type of harness system holds a patient upright while physical therapists stimulate the patient's legs and feet to walk on a treadmill.

"Essentially, we're creating and experimenting with a number of robotic systems aimed at helping rebuild neural pathways for people with spinal injuries," said Lars Oddsson, director of research at Sister Kenny.

For those beginning to walk with the new Ekso system, the intangible benefits are many, including, for someone who has been in a wheelchair for decades, simply being able to stand, walk around and look people in the eye again.

The Ekso looks like a kind of mechanized, computerized combination of a backpack and leg braces. Patients wear it with straps below the knees, on the thighs, around the stomach and over the shoulders. Plates under each foot are attached to motors and lift up. More than two dozen sensors feed information into the Ekso's computer, which uses it to decide how and when to step.

Upper-body strength needed

Patients must have at least some upper body strength to use Ekso because they must use a walker or crutches when wearing the device to ensure their balance. For the current model, they also must be lighter than 220 pounds and between 5 feet 2 inches and 6 feet 2 inches tall.

The device has three modes. In the most advanced, fully automatic mode, the device takes a step when the patient shifts his weight to the side and leans forward.

They have to work up to that, though. In the most basic mode, therapists talk the patient through the proper motions, and one of them uses a hand-held remote control to trigger each step. In an intermediate mode, the patient triggers each step via a button on one crutch.

Ayscue was still in the first mode Thursday, and all the patients using it will be for a while as they and the WakeMed therapists learn how to use it.

Eventually he will transition to trigger his own steps with buttons on one crutch.

The batteries last about three hours, but can be quickly swapped out for fresh ones.

Robot carries its own weight

The Ekso is designed to carry its entire weight, about 45 pounds, but the patient's weight goes through the patient's own legs, something the company believes will help fight the loss of bone density, a common problem for those who spend significant time in wheelchairs.

About 350 patients nationwide have used the device so far, said Bender, the company CEO. So far, there have been no falls. But using it in a controlled environment with trained experts just inches away is much different from using it at home.

A home model will be more elaborate in its function, but lighter, slimmer and have a look that's more low-key, he said.

"We have to design a system that's comfortable enough and appealing enough that's it's something you would be proud to wear," he said. "There could be more than one model, and eventually it could become like when we choose our pants in the morning, the jeans of the future."

That first "personal unit" also will need to have fall-prevention features. Also, cost and who pays are key issues. The current model costs $140,000, with a $10,000 annual service contract, Bender said.