HAIFA, Israel (Reuters) - paralyzed for the past 20 years, former Israeli paratrooper Radi Kaiof now walks down the street with a dim mechanical hum.
That is the sound of an electronic exoskeleton moving the 41-year-old's legs and propelling him forward -- with a proud expression on his face -- as passersby stare in surprise.
"I never dreamed I would walk again. After I was wounded, I forgot what it's like," said Kaiof, who was injured while serving in the Israeli military in 1988.
"Only when standing up can I feel how tall I really am and speak to people eye to eye, not from below."
The device, called ReWalk, is the brainchild of engineer Amit Goffer, founder of Argo Medical Technologies, a small Israeli high-tech company.
Something of a mix between the exoskeleton of a crustacean and the suit worn by comic hero Iron Man, ReWalk helps paraplegics -- people paralyzed below the waist -- to stand, walk and climb stairs.
Goffer himself was paralyzed in an accident in 1997 but he cannot use his own invention because he does not have full function of his arms.
The system, which requires crutches to help with balance, consists of motorized leg supports, body sensors and a back pack containing a computerized control box and rechargeable batteries.
The user picks a setting with a remote control wrist band -- stand, sit, walk, descend or climb -- and then leans forward, activating the body sensors and setting the robotic legs in motion.
"It raises people out of their wheelchair and lets them stand up straight," Goffer said. "It's not just about health, it's also about dignity."
Kate Parkin, director of physical and occupational therapy at NYU Medical Centre, said it has the potential to improve a user's health in two ways.
"Physically, the body works differently when upright. You can challenge different muscles and allow full expansion of the lungs," Parkin said. "Psychologically, it lets people live at the upright level and make eye contact."
Iuly Treger, deputy director of Israel's Loewenstein Rehabilitation Centre, said: "It may be a burdensome device, but it will be very helpful and important for those who choose to use it."
The product, slated for commercial sale in 2010, will cost as much as the more sophisticated wheelchairs on the market, which sell for about $20,000, the company said.
The ReWalk is now in clinical trials in Tel Aviv's Sheba Medical Centre and Goffer said it will soon be used in trials at the Moss Rehabilitation Research Institute in Pennsylvania.
Competing technologies use electrical stimulation to restore function to injured muscle, but Argo's Chief Operating Officer Oren Tamari said they will not offer practical alternatives to wheelchairs in the foreseeable future.
Other "robot suits", like those being developed by the U.S. military or the HAL robot of Japan's University of Tsukuba, are not suitable for paralyzed people, he said.