Surgeons at a Scottish hospital are using a robot to help carry out knee operations, BBC Scotland can reveal.
The technique is being tested at Glasgow Royal Infirmary where 150 patients are involved in trials.
It is part of a collaboration between surgeons, bio-engineers and a US health care company and could result in more effective knee replacements.
Each robot costs £750,000, but the procedure could also cut recovery times to a matter of days, saving costs.
One of the first patients to undergo the procedure using the robot was 70-year-old arthritis sufferer May Walker, who had the same operation on her other leg 11 years ago.
She said: "The last time, when I recovered, I had blood transfusions and pain.
"This time I can't feel pain at the moment. My knees are still numb with the anaesthetic but it's absolutely amazing how I'm feeling."
Mrs Walker expects to stay in hospital for just three days compared to eight days the last time.
Eventually recovery time is expected to come down to just 23 hours.
The robot guides the surgeon's hand, showing where he needs to cut bone away and gently resisting him if he tries to cut the wrong area.
Professor Philip Rowe, from Strathclyde University's bioengineering department, said: "When it came down to surgery we were still relying on saws and carpentry.
"The robot brings the accuracy and precision of an industrial tool."
Images of the patient's knee are loaded into software which controls the robot's movements.
Sensors are placed on the patient's knee to tell the robot its exact position.
A picture on a screen tells the surgeon which area of bone needs to be removed - with an accuracy of within a millimetre.
Business development manager Benny Hagag, from manufacturers Mako Surgical, said it would enhance the skills of the doctors.
"It's not replacing a surgeon, it's actually working with the surgeon, and letting the surgeon do a better job every day," he said.
Surgeon Mark Blyth agreed: "One of the problems with traditional techniques is that we rely on visual guides to ensure the accuracy of our surgery.
"That generally means making bigger incisions because if you can't see what you're doing you can't be sure if you're accurate.
"This will allow us to slowly reduce the size of our incision and that reduces pain and swelling post-operatively."
The robot could also open up an opportunity to create 'personalised' joints.
Current replacements are designed for average-sized bones and to fit onto the flat cuts from a saw.
But the robot can help make cuts of any size and shape.
Each robot costs £750,000, but if it can speed up recovery times for one of the NHS's most common operations it could prove cost-effective.