Timaru man Colin Murdoch was one of the world's great inventors. Produced by Justin Gregory.

It's entirely possible that you are alive because of one man.

"I suddenly got a bright idea."

In the town I grew up in, there was a man who knew how to do things.

His name was Colin Murdoch; he was a chemist and the kind of guy people would ask to solve problems for them. He always said yes and he always got the job done.

Colin was an ideas man and an inventor. In 1952, he had a very big idea indeed.

On a flight between Auckland and Christchurch, Colin took out his fountain pen to write something down. As he took the cap off and put it back on again... inspiration struck.

Using the same fountain pen, he drew a design for what would become one of the 20th century's most important medical inventions; the disposable, pre-filled hypodermic syringe. He was 23 years old.

In his home of Timaru, though, he was always known as the tranquiliser gun guy.

Colin Murdoch was born in Christchurch in 1929 into a family of chemists. He must have been an interesting kid; dyslexic, ambidextrous, experimenting with chemicals, making his own gunpowder for the pistol he'd built. He wanted to be a surgeon but was steered towards pharmacy, opening his first practice in Timaru at the age of 25.

Three years later a female friend set Colin up on a blind date with a local girl called Marilyn Tregenza. He turned up to the date at the cinema with his leg in plaster. He'd broken it skiing.

"And at the end of the performance she (the friend) said 'oh you can take her home'," remembers Marilyn today. "And he had a big plaster on. I'm not really sure how I got home, but I did."

They were married six months later. Marilyn discovered Colin's inventive bent when he moved a metal lathe into their top floor flat.

"And the two elderly ladies downstairs wondered what on earth the noise was."

Syringes in the 1950s were made of expensive glass or steel and had to be used multiple times across different patients. As a chemist and a man keen on medicine, Colin knew the risks of cross-contamination they posed, even when properly sterilised. What was needed was a single-use product, made from inexpensive materials, that could be disposed of after use. Plastic was the answer and Colin was the man.

He took his prototype to the New Zealand Health department who dismissed it as too futuristic. So Colin took out patents in Australasia and put the syringe out to market where, after a slow start, it's fair to say, it did pretty well as a concept…

Go to this episode on rnz.co.nz for more details