In 2012, a single pair of prosthetic legs ignited an international debate. Did South African athlete Oscar Pistorius's carbon-fibre running blades confer an unfair advantage over other able-bodied competitors? Did this technology, the International Olympics Committee asked, take him beyond normal human limits? For the Cybathlon, a new international sporting event taking place in Zurich in October 2016, the question of limits is beside the point.
"At Cybathlon we allow any kind of technology," explains the event's founder and organiser Robert Riener, a professor of sensory-motor systems at ETH Zurich. Technology such as non-invasive brain-computer interface (BCI) caps, with which participants compete to control a computer game avatar with their mind. Or functional electrical stimulation, used by patients with lower-body paralysis to activate their muscles and pedal recumbent bikes around a track. New designs in powered exoskeletons, leg and arm prosthetics and wheelchairs will be tested not only for speed and flexibility, but also their ability to cope with the kind of daily tasks, such as climbing stairs or opening a jam jar, for which current prosthetics are so inadequate.
"Allowing things such as motors and BCIs means we can include patients with more severe disabilities, patients who are almost totally paralysed," says Riener. "It's about showing the skills that our athletes can have in combination with technology."
The best comparison, he suggests, is Formula One racing - there are awards for both athletes and the technology. And, just as technology such as carbon fibre and traction control - developed by teams of world-class engineers for the sole purpose of getting their car round a track faster than anyone else - has changed the vehicle we drive, so Riener hopes the competitive spirit of Cybathlon could produce innovations that reshape humans bodies themselves.
"Only a quarter of arm amputees are using a prosthetic," he says. "There is a great need to improve these technologies. In the long run we hope that the devices developed for this competition will become available, affordable, and will improve people's quality of life."
Although the competition is geared towards daily obstacles, the challenges are not trivial, explains Aldo Faisal, senior lecturer in neurotechnology at Imperial College London and captain of the university's Cybathlon team.
"In the prosthetic-arms race, you have to move a ring around a metal hoop without touching the metal. Myself and another able-bodied colleague couldn't do it," he says. "Putting this equipment to the test in these sorts of events challenges engineers not just to make something that looks nice from an aesthetic point of view, but that can really compete in a more rugged sense."
For the powered wheelchair race, Team Imperial took a standard, commercially available chair and hooked it up to a specially developed eye-tracking system, which costs just £20 to produce - around 800 times less than comparable equipment. "It surprised me how good the control with the eye-tracking actually is," says the team's wheelchair pilot Sivashankar Sivakanthan, whose spine was reconstructed with titanium following damage caused by a tumour in his T1 vertebrae. "I just look where I want to go and the chair will take me there. It took ten minutes to get used to and then I was away. That is what this technology should be about. It should be easy and versatile, where you can implement it in real life for severe patients."
Although Sivakanthan is not paralysed himself, the team are excited about the potential applications for those who are.
"We have people able to lift two tonnes with the support of a full-body exoskeleton," Faisal says. "If we incorporate eye-tracking or brain computer interfaces instead of joystick control, then we could have a paralysed person working at, say, a shipyard, with many times the strength of the average man. This technology is non-invasive. We're not going to be seeing cyborgs running around half-cut-up to accommodate this tech. We're talking about things you can basically step in and out of."
Next is making sure these innovations and their application get the attention they deserve. Riener is currently in negotiation with the organisers of the Summer 2020 Olympics in Tokyo, who want to run the Cybathlon in the same year. "Exoskeletons are often presented in relation to the military," says Faisal. "It's important to show the civilian, pacifist uses this technology can have. For that, Cybathlon is a beautiful vehicle: a peaceful, friendly competition, just like in the Olympic spirit."