Bionic legs enable paraplegics to walk

The Toronto Star:

About the eLegs prototype:

A paraplegic for 18 years, Amanda Boxtel stands from her wheelchair and takes a few tentative steps.

She beams as the bionic skeleton she is wearing helps propel her legs forward.

“To take my first step … was just astounding … and then I took another step and another one,” she exclaims afterwards.

It is a dream come true for Boxtel, who was paralyzed in a skiing accident.

Bionic skeletons, known as exoskeletons, are the latest technology in the race to help paraplegics achieve the impossible and walk again.

One of the first of these prototypes, eLegs, was unveiled last week by California-based Berkeley Bionics.

The device has crutches with embedded sensors that move a person's right leg forward as the left crutch advances and vice-versa, using artificial intelligence.

While it seems amazing, it won't be for everyone.

Candidates for the device will need enough upper body strength to get out of a wheelchair alone, said CEO Eythor Bender.

It could help people with muscular dystrophy, ALS, polio or paralysis resulting from stroke or injury and people in rehabilitation.

Leandre Casselman, a spokesman for Canadian Paraplegic Association Ontario, was concerned that sensors might mistake spasms for voluntary movements, since some people have strong spasms in their legs.

Casselman, a quadriplegic, said the device's primary advantage might be outdoors. An exoskeleton might give better access to nature and areas where wheelchairs have trouble, such as on grass, gravel and sand.

On the other hand, Jaimie Borisoff, a paraplegic following a spinal cord injury 20 years ago, said he probably wouldn't use it outside because he can go places much more quickly in a wheelchair.

Borisoff, a research engineer at a University of British Columbia medical research centre, added most of the paraplegic community would prefer advances around other quality of life issues.

However, “it's a step in the right direction.”

“The end-all and be-all would be a cure,” agreed Casselman.

One such cure may involve stem cell therapies.

“In the not-so-distant future, these kinds of therapies will transform the practice of medicine, giving real hope that we will be able to restore a patient's ability to walk,” said Michael Rudnicki, a stem cell biologist at Ottawa Health Research Institute.

Another promising treatment involves electrical stimulation.

Muscles are stimulated to contract “in a meaningful way” while patients walk on a treadmill or with assistance an hour a day for eight weeks, said Milos Popovic, senior scientist at Toronto Rehab. They should then be able to walk on their own, although a walker or crutches may be needed. However, “if you have patients (with) damage so profound that neurologically they will never improve, these devices are great,” he added.

At first, eLegs will only be available to rehabilitation centres. They should start to show up in select clinics in Canada by 2012, Bender said. While the initial price to clinics may be in the $90,000 to $100,000 range, it's too early to say what it might cost when it becomes more widely available.

Similar exoskeletons include ReWalk, and Rex, creations of companies in Israel and New Zealand respectively, and HAL, being developed at a Japan university.

Berkeley Bionics based its device on technology developed with University of California Berkeley that helps soldiers prevent back injuries while carrying 90 kilogram loads over all terrains, Bender said.

• For now, the prototype is built for those who can self-transfer from a wheelchair to a chair, are between 5-foot-2 and 6-foot-4 tall and weigh 220 lbs. or less

• Weighs 20 kilograms, its own weight is supported by the machine itself

• Worn over regular clothes and shoes, it is held on using Velcro straps, backpack-style clips and shoulder straps. With practice, can be put on or taken off in a minute or two.

• Prototype battery stays charged more than six hours under nominal use in a rehabilitation setting

• Walking speeds vary by wearer, but in excess of three km/h can be attained

• Users can take their first steps after two or three hours of training and should be comfortable using eLegs after five to 10 sessions