4 . Three paralysed (瘫痪的) men, who were told they would spend the rest of their lives in a wheelchair, are able to walk again, thanks to an electrical device, which was placed around the men’s spines (脊柱) and boosted signals from their brains to their legs.

The first patient to be treated was 30-year-old Swiss man David M’zee, who suffered a severe spinal injury several years ago in a sporting accident. David’s doctor said he would never walk again. However, thanks to the electrical device developed by a team at a public research university in Lausanne, Switzerland, he agreed to take part in a trial led by Dr. Courtine at the university.

“I came with my daughter, Charlotte, who was one month old at the time. As we approached David, he looked her in the eye and said, ‘I will walk before you,’” Dr Courtine recalls. “When Charlotte took her first step she was 14 months old, by which time David was walking by Lake Geneva. He said to her, ‘I have beaten you.’”

David can now walk up to eight paces when the device is switched off and this is the first time that this has been recorded in a chronic (慢性的) spinal injury. However, out of the lab, in the real world, it is hard for David to walk more than a few paces. The signals from the device soon become uncomfortable and so can’t be used all the time. The system is also expensive and not reliable enough to be used out of the laboratory for day-to-day use, so it’s far from a cure.

David is the first of three patients who have benefited from the first wave of the treatment. Two other men have also managed to walk again, to various degrees.

The researchers plan to begin larger trials in Europe and the US in the next few years. If these go well, the researchers are confident the system could become more widely available.