Inspired by the organs used by parasitic wasps to stealthily lay eggs in tree bark, the catheter consists of four interlocking segments that slide over one another to allow for flexible navigation. It connects to a robotic platform that combines human input and machine learning to carefully steer the catheter to the disease site. Surgeons then deliver optical fibres via the catheter so they can see and navigate the tip along brain tissue via joystick control.
The AI platform learns from the surgeon’s input and contact forces within brain tissues to guide the catheter with pinpoint accuracy. Compared to traditional “open” surgical techniques, the new approach could eventually help to reduce tissue damage during surgery and improve patient recovery times and length of postoperative hospital stays.
While performing minimally invasive surgery on the brain, surgeons use deeply penetrating catheters to diagnose and treat disease. However, currently used catheters are rigid and difficult to place precisely without the aid of robotic navigational tools. The inflexibility of the catheters combined with the intricate, delicate structure of the brain means catheters can be difficult to place precisely, which brings risks to this type of surgery.
To test their platform, the researchers deployed the catheter in the brains of two live sheep at the University of Milan’s Veterinary Medicine Campus. The sheep were given pain relief and monitored for 24 hours a day over a week for signs of pain or distress before being euthanized so that researchers could examine the structural impact of the catheter on brain tissue.
They found no signs of suffering, tissue damage, or infection following catheter implantation. Lead author Dr Riccardo Secoli, also from Imperial’s Department of Mechanical Engineering, says, “our analysis showed that we implanted these new catheters safely, without damage, infection, or suffering. If we achieve equally promising results in humans, we hope we may be able to see this platform in the clinic within four years.”
“Our findings could have major implications for minimally invasive, robotically delivered brain surgery. We hope it will help to improve the safety and effectiveness of current neurosurgical procedures where the precise deployment of treatment and diagnostic systems is required, for instance in the context of localized gene therapy.”
Professor Lorenzo Bello, the study co-author from the University of Milan, says that “one of the key limitations of current MIS is that if you want to get to a deep-seated site through a burr hole in the skull, you are constrained to a straight-line trajectory. The limitation of the rigid catheter is its accuracy within the shifting tissues of the brain, and the tissue deformation it can cause. We have now found that our steerable catheter can overcome most of these limitations.”
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