Tuesday, December 1, 1998 Published at 00:55 GMT
Bionic woman has power to pedal
Julie Hill takes to the road
What could be more normal? Mother and son on a bike ride.
But for Julie Hill, this is a truly astonishing moment.
This is no illusion, however. Julie's legs are turning the wheels on her tricycle; she can stand up out of a chair and take albeit very faltering steps with the aide of a frame.
She can do all these things thanks to a revolutionary implant that directs a series of electrical impulses to the muscles in her legs.
But make no mistake, Julie is still paralysed. She spends most of her life in a wheelchair and the scientists, who are using her as a bionic guinea pig, have realistic goals.
"But we are not in the business of miracles. The notion that she is just going to get up out of wheelchair and do a walking marathon is_no way. There is what is possible and what is clearly not possible."
Nevertheless, to the casual observer what Julie, Tim and his team have already achieved is quite remarkable.
And they will see that it has been a hard, and at times, frustrating few years. Although the researchers managed to get Julie to stand fairly quickly, they have had difficulty getting her to adopt a posture that will allow her bionic system to mimic walking movements.
There are 47 muscles in each leg and they all require just the right amount of stimulation at just the right time. Getting the implant to match the sophistication of the human brain is no easy task.
Nevertheless, progress is being made and the program that allows her to ride the trike is the most striking evidence of that steady development.
Julie says, even with its currently limited capabilities, the implant has made a big difference to her life.
"I don't think I've ever, ever felt as fit as I do now. I'm getting such good aerobic exercise via the implant. It's really working well for me."
QED is broadcast on BBC 1 at 2130 GMT on Tuesday, 1 December.