German researchers have developed a miniature robot capable of drilling through bone and adjusting its path to steer around sensitive tissue such as blood vessels and nerves.
The NiLiBoRo (Non-linear Boring Robot) is being developed by the Mannheim Project Group for Automation in Medicine and Biotechnology, part of the Fraunhofer Institute for Production Technology and Automation IPA.
It is being designed for surgery on inner ear tumours. Currently the surgeons need to remove the entire mastoid bone, which is immediately behind the ear, to thread their way through some of the complex structures in this part of the head. The NiLiBoRo will drill a 5mm diameter hole allowing the surgery to be conducted in a less intrusive way.
Lennart Karstensen is a member of the team working on the NiLiBoRo and also spent some time in the mechatronic engineering department at Curtin University during his masters thesis. He says clever hydraulics are the key to the robot’s ability to drill around corners.
“The worm consists of a ‘head’ and a ‘tail’ section,” he said. “Both of these parts are connected with one another by means of a flexible bellows mechanism.”
Bladders in the head and tail section are altermately filled and emptied, anchoring that end while they are filled, allowing the head to be pushed forward while the tail is anchored or the tail to be drawn in while the head is anchored.
“We can alter the robot’s direction of travel by adjusting the bladders in the front section. For instance, if we wanted to move left then we fill the left bladder with less fluid than the right, which will cause the robot to veer to the left,” said Karstensen.
The robot’s path is monitored by an electromagnetic tracking system, capturing images of the robot using computer tomography.
The team is yet to be get the robot down to its final size with their current prototype five times larger than the planned final version. They hope to have the final version ready to be tested by physicians in two years time.