British researchers are developing a medical robot which can work out the intentions of a surgeon performing an operation, making surgery easier and more precise.

They hope new software will lead to less invasive operations, for example when conducting a cardiac bypass or tumour removal, allowing patients to recover more quickly.

The improvements have been made to the most advanced robotic surgeon on the market, the Da Vinci. It allows surgeons to sit at a viewing console directing the movement of the robot's mechanical arms inside the patient's body. The research team is working on using the surgeon's eye movements to direct the robot, getting the best out of both human and machine.

"We want to empower the robot and make it more autonomous," said computer scientist Professor Guang Zhong Yang, of the Hamlyn centre for robotic surgery at Imperial College London.

He said robotic surgeons are currently completely under the control of the surgeon. The robot responds only to the surgeon's hand movements. "There's a large amount of information that is not being explored at all. That's the human part."

The team has added a device which tracks the surgeon's eye movements. By working out precisely where each eye is looking, software can build up a 3D map of the area of tissue the surgeon is looking at. "What that does is it uses the surgeon's brain as a way in to calculating the depth of the tissue," said the surgeon Lord Darzi, who heads the centre and is a government health minister responsible for improving patient care.

This 3D map is allows the software to stabilise the image of moving tissues such as a beating heart to make surgery easier. It means that what the surgeon sees in the viewer is stationary, while his or her instruments are in fact moving up and down in train with the organ.

"The whole operating environment is moving at the same speed in relation to the organ that you are operating on and the instrumentation, the scope and everything else," said Darzi. "So we are essentially fooling the surgeons by showing them a static heart." This makes the procedure easier for the surgeon to perform.

Another new feature developed at the centre, and funded by a £10m donation from the Helen Hamlyn Trust, is "augmented reality". This allows the surgeons to see beyond the surface of the tissue to the structure they are operating on, for example a tumour or a blood vessel. The software does this by combining the image from the live tissue with scans taken before the operation of the area. The system's computer graphics give the illusion of see-through live tissue, with the position of the tumour beneath.

"It shows you the tumour in relation to its anatomical structure," Darzi said. That means the surgeon can be more precise and avoid cutting out large amounts of healthy tissue. "If you are reducing the physical and the psychological trauma that is one of the biggest costs from a patient perspective, and earlier discharge from hospital is a significant cost, earlier return to work is a significant cost."

The team is also working on setting up virtual "no-go zones" such as a healthy blood vessel, which the robot will not allow a surgeon to cut by mistake.