Dynamic intraoperative planning in robotic laser phonomicrosurgery

Introduction: One persistent drawback in surgical systems for laser phonomicrosurgery impacting even modern "robotic" devices is the mechanical joystick for laser control. This interface is currently the major limiting factor for improved surgical precision, quality and safety, requiring extensive practice and dexterity from the surgeon. Another limiting drawback is the lack of programming capabilities. Material and methods: A new robotic system was developed to overcome these drawbacks by offering a more ergonomic, intuitive and programmable interface for surgical laser control: A touch interface with dynamic intraoperative planning capabilities. The system is based on a large-range laser scanner that is fully controlled using a stylus over a tactile sensor. It is able to control the laser in real-time over the entire surgical field and features path memorization allowing for accurate repetitions of surgeon-defined laser paths. This feature enables surgical action visualization before execution and unmatched control over long cuts. Laser paths of any shape and length are dynamically planned also using the intuitive stylus interface. Results: Preliminary trials on ex-vivo swine larynxes and artificial targets have demonstrated the new system is highly intuitive, effective and safe: Reductions of 80% in maximum absolute error and nearly 50% in RMS error were recorded when using the stylus interface in path-following trials. The dynamic planning feature has also demonstrated its benefits: Practically no error was observed in trials, which recorded only 0.03mm average RMS error under a 40x microscope magnification. The research leading to these results has received funding from the µRALP European project.