HKU team designs neurosurgical robot for brain procedures

June 14, 2018 15:40
The compact design of the robot system can fit into a standard MRI head coil without any special modification. Photo: HKU

An engineering team from the University of Hong Kong has developed a neurosurgical robotic system that can perform delicate brain surgery inside a magnetic resonance imaging (MRI) scanner.

The team, led by Kwok Ka-wai, an assistant professor in HKU's Department of Mechanical Engineering, made a breakthrough by inventing a robotics system capable of conducting bilateral stereotactic neurosurgery inside an MRI scanner, according to a press release.

Stereotactic neurosurgery, which is a medical operation to localize and treat specific regions in the brain, requires extreme accuracy in order to prevent electrode stimulation from affecting surrounding healthy tissue.

Such surgery is one of the ways to treat brain diseases like Parkinson’s Disease and major depression.

However, metallic components used in the neurosurgery are forbidden in MRI scanners, which uses strong magnetic field to probe the targeted organ.

Therefore, traditionally, surgeons will locate the targets in MRI scanners before opening the patient’s skull.

But brain tissue shifts, so does the targeted area.

To ensure the surgery won’t damage the brain tissues nearby, patients need to stay awake under local anesthesia and interact verbally and physically with surgeons.

The new technology developed uses a liquid driven tele-operated system, so the metallic and electric part of the robot will be far from the MRI scanner and will not interfere with it, Kwok said.

Hence, surgeons can carry out the surgery while monitoring the situation and the location of the target in MRI scanners, which can produce 40 scanning images per second.

With much higher precision, the patient can have less invasive procedures and no longer needs to stay awake during the whole procedure.

Operation time is also shortened to 6 hours from the normal 8 hours, Kwok added.

He said there is still 1.7-millimeter sighting error, which needs to be further reduced to ideally one millimeter.

The team will conduct a pre-clinical validation with neurosurgeons led by Professor Poon Wai-sang and Dr Chan Tat-ming from the Chinese University of Hong Kong.

Although engineers overseas have developed a manual operation system to adjust the aiming manually, the electric mortar used in the device will interfere MRI scanners, so a patient needs to be moved in and out of the scanner throughout the operation, Chan pointed out.

This system invented can spare the unnecessary effort, he said.

The team believes the applications of the system won't be limited to brain surgery, but can also prove helpful in cardiac catheterization, and biopsy of prostate or breast.

The research team beat some shortlisted universities and companies including MIT, Harvard, and DeepMind and won the Best Conference Paper Award in ICRA 2018, the largest international robotic science conference.