A major problem when operating on the brain is trying to reach a lesion whilst avoiding obstructions. A traditional straight needle insertion has the potential to injure an area, causing irreversible consequences, or the surgeon could deem it too dangerous to attempt, resulting in an inoperable diagnosis.
Inspired by the way certain wasps lay eggs inside plants, the Imperial team’s design for a flexible, steerable needle is made of multiple segments, held together by an interlocking mechanism. The reaction force during the insertion process is said to allow it to bend to create the curvature.
The biologically inspired robotic probe, codenamed STING (Soft Tissue Intervention and Neurosurgical Guide), is said to change its direction smoothly by means of a “programmable bevel” tip. Maxon EPOS 24/2 DC motor positioning controllers (closed-loop) are employed using a strategy first developed for car-like robots. An electromagnetic position sensor is embedded at the tip of the probe.
The Imperial team is also prototyping the software using the open source Robot Operating System (ROS) and have focussed on the API interface, using Linux in particular. Maxon’s controllers are claimed to allow API customisation, which has helped the team to produce a set of libraries to ease the process.
The Imperial College team has recently been awarded a, €8.3million Research and Innovation Action (RIA) grant for robotic assisted neurosurgery to take this research to the next stage, with in vivo deployment expected within the next four years.
