Robots have joined the staff of doctors and nurses at two west London hospitals.

At Hammersmith Hospital in Du Cane Road, Shepherd's Bush, a robot has been introduced to reduce levels of infection, including superbugs MRSA and clostridium difficile.

The 'vapour-decontaminating' robot works by letting out hydrogen peroxide fumes into a sealed room, killing all harmful organisms in less than two hours.

Anthony Sewell, project manager at Imperial College Healthcare Trust, which runs Hammersmith hospital, said: "While our patients will be the first to benefit, the work we're doing will enable hospitals to fight infections more effectively."

At St Mary's Hospital, in Praed Street, Paddington, another robot is used to perform pioneering surgery on a potentially deadly condition. Patient James Arnold, 78, was successfully treated for an aneurysm, or swollen blood vessel. The robot was used to insert an implant into the vesselthrough which blood can flow.

Professor Nick Cheshire, a consultant surgeon, said: "These technologies are proving to be safer and more cost-effective than open surgery. This project is a perfect example of how our Trust has literally taken research from the bench to the bedside."