Family doctors who use the system say the global positioning system (GPS) equipment could "transform" their out-of-hours work in remote areas of the country.

The equipment uses the Navstar satellite system, which is operated by the US Defence Department.

Doctors could key in their patients' postcode and then be directed to within 200 yards of the house they need to visit when they are on call.

However, the government or private companies would need to provide funding to equip GPs with the technology.

Transformation

Dr John Wynn-Jones, who runs a surgery in Powys, mid-Wales, is director of the Institute of Rural Health. He uses the GPS system as a directional aid when he goes hiking.

The institute is calling for funds to be made available so GPs can use the system.

At the moment, ambulance services use the technology to help them attend calls more quickly.

Dr John Wynn-Jones: Transformation

Dr Wynn-Jones said finding patients in out of the way places could be difficult.

"In remote areas mobile phones often don't work well, if at all, and it can be a nightmare trying to find a patient in the middle of nowhere when it is dark and the weather is bad," he said.

"It would be great if rural doctors could have the system considering the area they have to cover, it would alter our work and be a boost to our work. It's a shame we don't have the resources.

"There's a wonderful opportunity here for a company or a university developing IT applications that doctors could take up.

"The institute would support such a move, or indeed anything that would make the lives of doctors or nurses working in rural areas where they have to deal with emergencies easier and improve patient care."

Funding source

One potential source of funding was the GP out-of-hours development fund, he said.

The government set up the fund following negotiations with the British Medical Association. It is intended to provide money to improve out-of-hours services.

It is worth £43.4m this year. The value of the fund changes annually depending on the previous year's spending.

Rural GPs are also turning to satellite phones to ensure they are contactable in far-flung parts of the country.

Dr Wynn-Jones added: "There aren't many doctors who have the equipment at the moment, but it is becoming increasingly popular."

Dr Gordon Baird is a member of the Royal College of GPs' rural doctors group.

He uses the GPS when he goes sailing, but has not yet worked it into his practice as a GP. He was intrigued by the prospect of using the system to locate patients.

"It's a very exciting prospect," he said. "However, its successful use depends on excited patients giving accurate details of their location and operators taking them down correctly."

How the system works

The GPS is used by the military to lock on to enemy targets, and can be used to pinpoint a user's position on the globe.

The Federation of American Scientists describes the Navstar GPS as "a constellation of orbiting satellites that provides navigation data to military and civilian users all over the world".

Members of the 50th Space Wing located at Falcon Air Force Base, Colorado, run the system.

The federation says: "GPS satellites orbit the earth every 12 hours emitting continuous navigation signals. With the proper equipment, users can receive these signals to calculate time, location and velocity.

"The signals are so accurate, time can be figured to within a millionth of a second, velocity within a fraction of a mile per hour and location to within a few feet.

"Receivers have been developed for use in aircraft, ships and land vehicles as well as for hand carrying."