Volunteers trialling 2014's medical breakthroughs

A bionic pancreas for people with Type 1 diabetes, and a new drug to treat certain skin cancers - these are just some of the medical milestones reached this year, with the help of volunteers taking part in trials.

In the latest in a series of special reports, the BBC's Victoria Gill has met the patients who have been contributing to some of 2014's most significant breakthroughs.