Doctors in Vancouver, B.C., as well as London and Toronto in Ont., are testing an experimental treatment approach that they hope will help the thousands of Canadians with herniated discs.

'Slipped discs', as they are sometimes called, occur when one of the soft cushions that rests between the bones of the back ruptures and slips out between the vertebrae. The disc material can then push on spinal nerves, sending pain down the back and legs.

The vast majority of herniated discs occur in the lower backs of older Canadians, either because of muscle strain injuries or simply through general wear and tear. The injury typically means months or years of painkillers, steroid injections, and bed rest. In some cases, surgery is needed to remove the disc altogether.

But now, a Canadian doctor has invented a device called the AO-1000 that he hopes will give patients another option. The device takes oxygen and turns it into ozone gas and then sends it through a needle into the herniated disc.

The device's inventor, Dr. Kieran Murphy, a radiologist with Toronto's University Health Network, says the ozone helps shrink the disc and allows it to pull away from spinal nerves.

"It interacts with a protein in the jelly centre of the disc and breaks it down into carbon dioxide and water," he says.

He adds that the entire procedure takes less than an hour and is far less expensive and risky than surgery.

"It is a cheap, cost-effective way of doing things that is minimally invasive," Murphy says.

Ozone disc therapy is already used in Asia and Europe, but it is still considered experimental.

A 2010 meta-analysis of 12 different studies and 8,000 patients found that oxygen/ozone treatment of herniated discs is an effective and "extremely safe" procedure.

Now, doctors in Vancouver, Toronto and London, Ont., are testing Murphy's device on about 90 patients.

Active-O, Inc., the company that owns the rights to the AO-1000 is sponsoring the trial.

One of the patients helping to test the device is Greg McMillan. Not long ago he was having trouble moving because of pain from a herniated disc. Then he had the experimental treatment last July.

"The day after I had the ozone injection treatment, it felt like I never had a back problem," he says.

Studies conducted in Europe using similar ozone devices found that the treatment didn't work in about a quarter of patients, although it's unclear why some patients benefitted and others didn't.

Pam Sullivan received the ozone injection treatment in early June and is still waiting to see if it worked. She said her back pain had become so bad that she couldn't stand or sit for long periods of time.

"I went from being a normal person working at a desk, going on vacations, going out for movies… I haven't been to a movie in almost two years," she said.

Standard medical procedures didn't help Sullivan, and she said she's spent thousands of dollars on alternative treatments, but nothing seemed to work. The pain was so frustrating that she decided to get the treatment.

"I know it's experimental, but what choice do I have really?" she said.

The Canadian researchers are planning a future trial that will compare the treatment with a placebo, depending on the results of this first study.

With a report by CTV News' medical correspondent Avis Favaro and producer Elizabeth St. Philip