Doctors belileve that health care is set to undergo more sweeping changes in the next two decades than have occurred in the last 2,000 years.

International journals from around the world will dedicate their issues this week to examining the impact of new technology on the future of medicine.

Prestigious titles such as the British Medical Journal (BMJ) and the Journal of the American Medical Association (JAMA) have commissioned experts to predict how medicine will develop in the 21st century, and to discuss the ethical issues that implementation of new technology will raise.

Some of the advances that scientists predict will be made include:

• In-patients will be implanted with sensors when they are admitted to hospital that will automatically do more than 40 laboratory tests

• Electronic noses will detect and differentiate the odours of growing bacteria and instantly identify the bacteria causing ear, nose and throat infections

• Surgery will become less common as new types of treatment, particularly vaccines and gene therapy, take over from the scalpel

• A biochip photosensor will be implanted in the eye as an artificial retina for patients who are going blind

• Diabetes sufferers will have a glucose monitoring sensor implanted under the skin and an internal insulin reservoir that automatically adjusts insulin doses

• Toilets will analyse urine samples and automatically send a report to a user's doctor if necessary

• Vaccines containing chunks of DNA that could be fired through the skin, inhaled or incorporated into food

• Hospitals will rely on robots, which will run central supply services and process pharmacy orders

• Wheelchairs will allow users to have eye-level conversations, drive through sand and gravel and climb curbs and stairs

If the experts are to be believed, the hospital of the future will bear little relation to its present day cousin.

Intensive care a thing of the past

Separate hospital beds and operating tables will be replaced by one multi-purpose piece of equipment which will be embedded with sensors to monitor vital signs and provide mechanical ventilation, intravenous infusion and cardiac defibrillation, such that central intensive care units may no longer be needed.

Click here to read about the hospital of the future

In addition, ceiling vents in hospital lobbies will monitor visitors for any infections they may be carrying into the premises.

Consultations with clinicians based overseas will become the norm, either by video-conferencing or via e-mail.

Genetic technology is predicted to be an area where intense ethical debate will rage.

The potential for gene therapy to transform medicine is almost limitless, but scientists suspect fears over its possible use to create a super-race will hold back the pace of change.

Click here to read about diabetes care next century

Dr Charles Wilson, director of the Institute for the Future, University of California at San Francisco, is one of the scientists who has contributed a piece to the BMJ.

Among many radical ideas that he put forward is the idea that controversial animal to human transplants could become commonplace.

He said: "In future, pig farms could be sited right next to hospitals, so that organs can be freshly harvested and transplanted more quickly."

Dr Richard Smith, editor of the BMJ, said it was important that a wide-ranging debate was held about the impact of new technology.

He said: "The message is that there are all kinds of exciting new technologies in the pipeline that could have enormous benefits, but could also pose substantial ethical problems - big questions such as can we afford it, and who will get access and who will not.