A new surgical robot can make the micro movements needed for a particularly delicate procedure: cataract surgery. Axsis, a system developed by Cambridge Consultants, is a small, teleoperated robot with two arms tipped with tiny pincers. It’s designed to operate on the eye with greater accuracy than a human.
Globally, 20 million people have cataract surgery every year, making it one of the most common surgeries in the world. Although complications are very rare, they still affect tens of thousands of people.
Cataracts happen when the natural lens of the eye gets cloudy and obscures vision. To restore a person’s sight, a surgeon cuts a small hole in the lens, scoops out the bit that’s gone cloudy, and replaces it with what’s essentially a permanent plastic contact lens.
The whole thing requires a steady hand, and the most common complication arises when a surgeon accidentally pierces the back of the lens, a thin membrane that is only a few millimetres off target, causing hazy vision.
Axsis aims to prevent this kind of human error. The device’s articulating pincers are mounted on arms about the size of drinks cans, with extremely light, strong “tendons” made of the same material NASA uses for its solar sails. These pincers can sweep across a 10-millimetre space – the size of the lens of the eye. This is just a demonstrations model; in the final product, the pincers will be replaced with scalpels.
To control the robot, the surgeon sits at a station nearby and uses two 3D haptic joysticks to move the pincers while watching their work on a screen. The image on the screen is enlarged, so the surgeon can make more precise movements, with the pincers operating at a tiny scale not possible with the human hand.
One benefit of the system is that the software disables certain boundaries from being breached. “It won’t let you make the mistake of punching through the back of the lens,” says Chris Wagner, the lead roboticist on the project.