The goal of Robocast project is to realize a robotic system to assist surgeons performing brain surgery through a very small hole in the patient’s skull.
The robot is aimed at holding instruments and at inserting them in the brain with smooth and precise movement according to surgeon’s needs. But not only. The breaking innovation of this project is in the intelligence of the system. Robocast is able to understand and manage the surgeon’s inputs together with diagnostic information from the patient and moreover with data reporting the 3D position of the operating device in the Operating Room.
The original idea will be developed into a demonstrator unit for in vitro experimentation (end of 2010).
The first step was to verify the current state of the art of surgical procedures and to check which robotic requirements were necessary to guarantee patient and medical staff safety during the operation. In parallel researchers defined a series of surgical procedures Robocast system must be able to perform.
In August 2008 the technical aspects of the Robocast project started and up to date the complex robotic system has been developed. This encompasses two modified commercial robots integrated with a unit able to hold the probe to be introduced through a “keyhole” opening into the skull of the patient.
An innovative goal of this project is the fabrication of flexible probe samples to guarantee minimally invasive neurosurgery. Therefore a probe with a biologically inspired design has been constructed and is currently being tested under laboratory conditions. The new probe will enable a range of new surgical tasks, such as curved trajectories, that are not currently possible.
To help surgeon driving the insertion of the probe, using a robotized procedure, an haptic device has been identified and adapted with an ergonomic stylus. This device provides the surgeon with a feedback of the resistance experienced by the instrument during the process. The force feedback information comes from the load cell sensing the force experienced by the tip of the probe during the advancement under linear actuator control.
The Robocast is a multi-task system monitoring and integrating positional information from a number of different sensors (e.g. optical, electromagnetic, force and ultrasound) in a pre-operative planning software. The planned motion path in the operative room, avoiding possible collisions and maximizing the safety for both the patient and the staff, is shown to surgeon to acceptance.
Surgical instruments movements inside the patient’s head will be planned based on surgeon experience and on medical images. Therefore a risk atlas, to manage errors in pre-operative planning, was created. Defined by neurosurgeons and based on internal diagnostic images, this atlas allows to define risky zones, such as blood vessels and NO-GO areas. Risk parameters for movement planning were compiled and sorted according to their importance. Taking these information into account, a user friendly pre-operative planning software based on open-source platform Slicer3D has been realized. This results in an autonomous system able to plan the best probe path inside the brain minimizing the patient risk. Nevertheless the surgeon remains the unique responsible of the intervention. He/she, in facts, is asked to accept or criticize the planner’s solutions. An effective and intuitive graphical interface visualizes the path proposed together with information about path risk, length and possible warning messages.
Once planned (in the pre-operative planner), the path followed by GP,FP, linear probe/ flexible probe is shown to the surgeon for acceptance. During the intervention, the operative room setting is registered through optical localization and before the robots approach the patient, the planned motion – avoiding possible collisions and maximizing the safety for both the patient and the staff - is shown to the surgeon for acceptance. An ultrasound system with high quality graphical renderings was included to improve intra-operative guidance and support for the surgeon.
Up to now a solution for handling the communication between system components was decided and a standardized protocol was chosen but some more provision are open for the work that is still in progress. In order to cooperate in the software development a central repository was implemented.
Starting from the beginning of the project (January, 2008) a fruitful cooperation between surgeons, radiologists and engineers has been leading to an easy to use but effective system for the assistance of neurosurgeons in the operating room.
Currently the progress of work is fully satisfactory.
