All the four patients are males in their 30s who became paralyzed due to work-related accidents. Except the most recent case who underwent surgery on Monday, the other three were able to control their leg movements and walk independently with the support of suspension devices after the surgery.

"One patient, upon being able to stand again after the surgery, was so excited that he wanted to send pictures to his mother," said Ding Jing, chief of neurology at Zhongshan Hospital Affiliated with Fudan University.

As the research progressed, the team became increasingly bold in encouraging patients to attempt new movements. For example, the second patient was able to lift his legs and extend his knees while seated on the third day following the surgery, while the third patient achieved lifts in both legs within an hour after the procedure. Through continuous signal collection, adjustment, and training, by the seventh day after the surgery, he could smoothly stride between parallel bars with the support of suspension devices and step over obstacles.

"They made progress day by day, which is crucial for instilling confidence in their rehabilitation," said Jia.

"I was able to walk for over 5 meters depending on my own movement intentions on the 14th day after the surgery. It was something I wouldn't have dared to dream of," said the first patient, a 34-year-old surnamed Lin from Guangdong province. He had been paralyzed for two years and was previously told he would never stand again.

The research team said their ultimate goal is for the patients to walk independently without suspension support, a process that may take about six months to a year.

Also notably, sweating in legs has been observed from the first three patients. "This indicates that the brain-spinal cord interface has stimulated nerve reshaping within the patients' bodies. If this continues, the ideal scenario in the long run will be patients walking independently without our devices," Jia said.

Globally, there are about 20 million paralyzed patients, who currently rely on passive rehabilitation and care. There is no approved product worldwide so far for rebuilding the gait of paralyzed patients.

Video by Wu Wanzhen.