LONDON A mechanical snake that can enter the body through natural orifices -- not an incision -- to perform operations is just one futuristic device researchers believe will transform traditional surgical techniques.
With a world recession looming and healthcare budgets under pressure, it may seem an odd time to be bullish about hi-tech surgery.
Robots, after all, are not cheap. The average selling price of the market-leading da Vinci system from California's Intuitive Surgical Inc is $1.35 million.
Some critics, including British fertility expert Robert Winston, have questioned the cost-effectiveness of robots when other treatments, such as cancer drugs, are being rationed.
But proponents note prices will inevitably fall as usage and competition increase, as happened with once-costly computers.
Tens of thousands of prostate, heart and other procedures are already being performed by robots, and experts predict machines will be used to penetrate deeper into ailing bodies in the years ahead.
In a university laboratory behind London's Science Museum, researchers are working on a new generation of hi-tech gadgets to take minimally invasive robotic surgery to the next level.
The prospect of robot arms probing into the abdomen may be alarming but their precision can mean less trauma, quicker recovery, a shorter stay in hospital and reduced tissue damage.
Among men needing prostate operations -- the biggest group to go under the robotic knife at present -- that means less risk of impotence, according to doctors who use the devices.
"It's not the easiest concept to describe to a patient," said surgeon Ara Darzi, co-director of the Hamlyn Center for Robotic Surgery at Imperial College London and a British government health minister responsible for patient care.
In his experience, patients are soon won over once the benefits are explained.
"Patients need to be reassured that this is not a machine operating independently. This is an enabling machine," he said.
Sitting at console and looking at a stereoscopic viewer, Darzi can direct his robot's multi-jointed pincers inside the patient's body using a series of joysticks and foot controls as he conducts gall bladder, cancer and other operations.
They may be state-of-the-art, but these robots are just the start.
"This is the tip of the iceberg -- this is the first car ever invented," Darzi told Reuters. "There is a huge amount of work in this field which will significantly enhance the ability of the surgeon to provide a much more precise, accurate procedure."
One idea that could soon become a reality is a device that uses the surgeon's gaze to direct tools by tracking the light reflected from the user's eyes, making operations simpler and less invasive.
Positive results with the eye-tracking system were presented at the International Conference on Intelligent Robots and Systems in Nice, France in September.
The natural orifice "I-snake" camera and surgery system, which would do away with the need for incisions altogether, is further down the track. The team at Imperial hope to have their oral or rectal access system ready for tests within 3-1/2 years.
Work is also under way on "augmented reality" software. This could use data from past patient scans to help surgeons visualize tumors or other structures underneath living tissue.
Another possibility is artificially stabilizing the image of moving organs, such as a beating heart, by creating robotic instruments that move in tandem with the patient's body.
"Currently, robots are used in relatively simple procedures," said Guang-Zhong Yang, joint head of the Imperial unit. "But in future, you will see them used in more advanced procedures, like beating-heart surgery."
Darzi and Yang are not alone.
In May this year, doctors at the University of Calgary in Canada used a robot called neuroArm to remove a tumor from a 21-year-old woman's brain in the first operation of its kind.
Privately held U.S. firm Satiety Inc, meanwhile, is testing a stomach stapler for obese patients that slides down the throat rather than requiring abdominal surgery.
Researchers at Germany's DLR Institute of Robotics and Mechatronics are working on a lightweight system called MIRO using the same robotic arm technology as is used in space.
And business is booming at Intuitive Surgical, whose installed base of more than 1,030 da Vinci robots at hospitals throughout the world is due to perform at least 130,000 prostatectomies, hysterectomies, heart valve operations and other procedures this year.
(editing by Andrew Dobbie and Sara Ledwith)