As a researcher into diabetes, the fact Moira Harrison struggled to control its symptoms was a cause of embarrassment.

She was fully aware of the problems and causes of the condition but found it almost impossible to keep her blood sugar levels under control.

For 15 years the university lecturer took four insulin injections a day and had hyopglycaemic attacks, or hypos, several times a week.

She said: "It was an absolute nightmare. I couldn't have any flexibility in my life and felt I was trapped by my diabetes.

"I had to eat at exactly the right time. If I visited a friend's house and dinner was late, I'd be in their cupboards trying to find something.

"My whole life revolved around my meal times and my medication. No matter how much I tried, I could not bring the condition under control."

It was while on conferences abroad that Dr Harrison, 45, who works at the University of Brighton, found the solution that was to change her life - an insulin pump.

The device, widely used on the Continent and in the United States, infuses short-action insulin when needed, meaning patients no longer have to have injections.

Instead, they can set the pump to give regular doses at certain times, adding more whenever needed.

Dr Harrison's life was transformed after just two weeks of using the pump.

She said: "The improvement came about really quickly. A nurse had to train me how to use it but once I got the idea, it was terrific.

"I had started to have problems with my eyesight, which was connected to the diabetes, but it has improved since I started using the pump.

"The thought of losing my sight was terrifying so this has given me such a boost.

"I can now eat and drink when I want to and have not had a bad hypo since I got it. Quite simply, it has given me my life back."

About 4,000 people in the UK now have the device but in 2000, when Dr Harrison, from Ringmer, near Lewes, heard of it, only a couple of hundred were in use.

She had been diagnosed with Type 1 diabetes in 1985. She found herself becoming more and more lethargic and started drinking litres of water every day.

The condition runs in her family. She said: "I knew the signs but tried to deny it at first. Eventually I had to concede defeat and started to get treatment."

The death of a PhD student at Sussex University from a hypo made Dr Harrison even more determined to find a way to control her condition.

She said: "It was devastating and frightening.

"The thought of dying suddenly like that was awful."

She said hearing about the pump was a godsend, adding: "Everyone had plenty of good things to say about it and I thought I had nothing to lose, even though it was not widely available in this country."

The success of the pump led Dr Harrison to appear as an expert witness on a National Institute for Clinical Excellence (Nice) advisory committee.

The committee agreed pumps should be made available on the NHS - guidance which comes into force in three months' time.

Dr Harrison had to pay £2,000 for her pump and spends up to £1,000 a year on supplies to go with it.

She eventually hopes to have the supplies paid for by her Primary Care Trust but is still waiting for a decision.

She said: "The Nice guidelines mean that if a patient fits the criteria and their consultant agrees, they can have an insulin pump if they want it.

"The problem is that this is not widely known so people may be losing out.

"The device is relatively inexpensive and could save money in the long term because people using it are likely to have fewer complications.

"If it works for them, the pump could change their life."

A spokesman for Brighton and Hove City Primary Care Trust said: "We will fund any Nice-recommended equipment or drugs prescribed by clinicians as we are required to do.

"But ultimately it is up to the clinicians themselves whether to prescribe it or not and they make that decision in consultation with their patient."