Enlightened self-interest in the best capitalist tradition lies at the root of a Woodstock business now growing at the rate of 30 per cent a year.

Owen Mumford, which began as a humble plastics mouldings company in 1952, is now a world market leader in producing instruments for people suffering from such chronic ailments as diabetes, multiple sclerosis and rheumatoid arthritis.

It may be sad that the company has grown on the back of the phenomenal growth of such diseases in recent years, but as sales and marketing director John Webb says, his company's products - various lancing devices used either by doctors and nurses, or by the patients themselves - are improving the quality of life for tens of thousands of people.

He added: "There is no doubt that diabetic people left untreated would cost the taxpayer a lot more than they cost now.

"Our stock-in-trade is making life easier for the patient."

So here is an example of an entrepreneur in a competitive field prospering by ensuring that ill people receive top class treatment, usually free - since the NHS picks up the bill in most cases.

The company, which will turn over £50m this year, now employs around 180 people at its Chipping Norton assembly plant on the Primsdown Industrial Estate, and another 190 at its Woodstock site.

In Chipping Norton, where Owen Mumford is the town's largest employer, an extension to its factory was recently opened by Tory leader and West Oxfordshire MP David Cameron.

It also has offices in the USA, France and Germany, employing another 25 people in addition to its ten-strong UK sales team. The firm makes more than half its turnover from exports.

Mr Webb said: "Ten years ago we decided to concentrate solely on medical supplies, rather than on general mouldings. We politely told existing mouldings customers that we could not work with them any longer."

As it turned out, the decision proved to be a good one - the company has gone from strength to strength ever since. One secret of its success is its policy of inviting constant feedback from users.

Mr Webb said: "We want to hear ideas, particularly ideas that begin: if only there was a device that . . . and then state the problem.' That is one way our products constantly evolve and improve."

Many of the devices produced by Owen Mumford are patented instruments designed to help patients extract, and then automatically analyse, small blood samples before injecting themselves with the correct dose of insulin, as determined by that analysis.

Many diabetes sufferers, for example, use the company's Autopen injection device, or the Autolet2, which allows them to fit a new sterile needle easily and, in the case of the Autolet, inject themselves without having to see the needle at all.

Mr Webb said that less than half the firm's business is now diabetes related, but clearly the alarming increase in incidence of that disease has boosted sales over the years.

According to the charity Diabetes UK, the number of people in the UK with the type 1 diabetes -which always needs treatment - has doubled every 20 years since 1945 to its present figure of between 250,000 and 300,000.

Obesity Also, there are 1.9m people with the type 2 version, which can to some extent be controlled by lifestyle changes. By 2050 the total number of UK sufferers is expected to hit ten million.

The figures are closely linked to the growing incidence of obesity. Britain has the fastest growth in Europe in people becoming officially overweight.

The firm began in 1952, when Ivan Owen and John Mumford established a new business in a small lock-up garage owned by Mr Owen's father, Tom.

Some of the medical products produced in those early days, including an improved version of the Macintosh Laryngoscope - a tool for examining the larynx- are now on display at the company's Woodstock headquarters.

By the 1960s, the firm had moved into a former glove factory in Woodstock but its products were varied to say the least, much of its moulding work being supplied to the automotive industry.

In the 1970s, the company had grown enough to move its plastics division to its present site in Tipping Meadow - once a rubbish tip - while continuing to produce medical products at the former glove factory in Oxford Street.

But it was in the 1980s that the company hit the big time with the success of its Autolet lancet, ideal for diabetes sufferers. Soon it was building sterile cleanroom facilities for producing lancets of different varieties.The rest, as they say, is history.

Today it is no exaggeration to say that Owen Mumford produces hundreds of millions of needles a year for use with its various devices, which are in turn used two or three times a day by sufferers.

Now the family firm - the managing director is Adam Mumford, a grandson of the founder - has come up with a product called Uniguard, which is the only disposable pen needle on the market.

It is designed to protect users from potentially fatal needle stick' injuries.

n Contact: 01993 812021, www.owenmumford.com