With a piece of shrapnel lodged close to his heart, Hollywood super-hero Tony Stark built a custom heart-plate - and red-and-gold armoured suit - to stay alive and transform into his high-flying alter ego, Iron Man.
In the late 1980s, a Detroit police officer was killed in the line of duty, but his body was chosen for an experimental government programme. He soon turns into Robo-Cop: half-man, half-robot.
Decades earlier, a former astronaut suffered a near-fatal car accident, but was rebuilt using $6m worth of robotics. His arm, legs and eye were replaced, and Steve Austin became known as the Six Million Dollar Man.
Today, these fantasies may be more realistic than many would believe, as the world's leading researchers are moving closer to using robotics to get humans back on their feet.
"It's not science fiction anymore," said Dr Miguel Nicolelis, a Brazilian neuroscientist at Duke University and researcher with the Walk Alone project, an international group of scientists that aims to rehabilitate individuals who suffer from severe body paralysis.
The patient is going to initiate the movement by imaging the kick. That signal that we record from the brain [is] going to be translated into the movements that we need to kick the ball.
As the world's attention turns to Brazil and the 2014 World Cup, a Brazilian patient who is paralysed from the waist down will walk onto the pitch during the tournament's opening ceremony in Sao Paulo on June 12, and kick a football using brain waves alone.
"The patient is going to initiate the movement by imaging the kick. That signal that we record from the brain [is] going to be translated into the movements that we need to kick the ball," Nicolelis told Al Jazeera.
Turning thoughts into action
Since January 2014, eight patients - Brazilians between the ages of 20 and 40 who suffer from severe or complete paralysis of their lower limbs as a result of spinal cord injuries - conducted training sessions in Sao Paulo to learn how to control virtual representations of their bodies using only their brain.
The project was largely financed by Brazil's Financing Agency for Studies and Projects.
"The person will have to do it eventually in front of 80,000 people screaming in a stadium. We are not doing something in an experimental room; the person must be able to deal with some stresses," explained Solaiman Shokur, an engineer working on the project at the Natal International Neuroscience Institute in Brazil's northeast.
During the World Cup opening ceremony, the patient will be outfitted from the waist down with a robotic vest (known as an exoskeleton), a backpack filled with computerised controllers and power generators, and a helmet applied to the patient's scalp to record brain signals, which control movement of the exoskeleton.
The exoskeleton will also simulate pressure and temperature when the paralysed legs make contact with the ground and with the football, allowing the patient to receive feedback as it happens - a type of "artificial skin", according to researchers.
"The subject feels when the robot is touching the floor. He has an understanding of where the legs are. This, together with the neuroplasticity of the brain, will help and will really increase the chances of rehabilitation and recovery of patients in the future," Shokur told Al Jazeera.
While neuroprosthetics is not a new branch of science - cochlear implants were introduced decades ago, and return a sense of sound to deaf or severely hearing-impaired persons - research into how brain waves can influence movement has progressed rapidly in recent years.
Elsewhere, scientists have succeeded in getting a woman, who had been unable to use her arms and legs for 15 years, to pick up a glass of water and drink from a straw using her mind and a robotic arm, while elsewhere, another man high-fived a friend in the same way.
Dr Gregoire Courtine is head of the Center of Neuroprosthetics at the Federal Institute of Technology in Lausanne, Switzerland. He estimated that about 50,000 people are afflicted by spinal-cord injuries every year, making this technology particularly relevant.
In experiments conducted on rats, Courtine has used a pharmacological mixture, electric stimulation and a robotic system to kick-start movement. After several months of training, the rats were able to stand, walk and run, he said.
"Imagine that the locomotion system is a car and the engine is the spinal cord. The transmission is interrupted, and the engine is dormant, turned off. How do you re-engage the vehicle? First, you need to provide the fuel; second, you need to press the accelerator pedal; and third, you need to steer the car," Courtine told Al Jazeera.
But Courtine cautioned that the technology's effectiveness for humans remains untested. "All these tools are not a cure, but for neuro-engineering in the next 20 years, there will be tools for some of the people to make their lives better, to improve their quality of life," he said.
According to the Walk Alone project team, the World Cup exhibition builds on 30 years of research in neuroscience, and over a decade of work on technology allowing the exchange of information between human brains and robotic equipment.
"It is just literally the first step to get to the point where any patient can have assisted-technology like this," Nicolelis said. "I hope this is going to be remembered as a milestone for science education and for science dissemination."
Source: Al Jazeera