gms | German Medical Science

Objective: Neurosurgery was one of the first clinical applications of robotics and continues to be a topic of current interest. Neurosurgical stereotactic applications require high spatial accuracy and precise targeting to reach the anatomy of interest while minimizing collateral damage. The modular robot system iSYS1 (iSYS Medizintechnik GmbH, Kitzbuehel/AT) has been used to build a setup for neurosurgical applications. Main advantage of the robot setup is its small size and the inherent safety of the chosen kinematic concept. Beside of a description of the robot system, the paper outlines different setups for the robot and the elaborated workflows for selected applications. Results from first phantom and clinical trials conclude the report.

Method: The robot system used in the present study originally has been developed for US- and CT-based procedures in interventional radiology. The combination of high dexterity and small size seems to be a perfect prerequisite for this robot to be used in neurosurgical applications. The iSYS1 robot system basically consists of two high-precision positioning modules, each of which having two degrees-of-freedom (DOF) in x-y-configuration. For needle angulation a parallelogram structure is established by relative motion of two parallel "fingers" connected to each other by means of spherical joints. The integrated design allows high dexterity regardless of the small footprint of the system. The robot allows any possible combination of 2-DOF needle angulation (±35°) and 2-DOF positioning (±20 mm for each axis). Information about the target position is being provided by a standard neuro-navigation system connected to the robot (StealthStation, Medtronics/USA) with a dedicated data interface.

Results: Workflow for different clinical applications have been elaborated, e.g. for brain biopsy, intra-ventricular shunt placement, and placement of depth electrodes for epilepsy monitoring. Future applications include endoscope guidance and DBS placement. The aforementioned workflows have been extensively evaluated in different phantom trials and in a clinical study. Both, accuracy of the tool placement as well as reduction of procedure time by using the iSYS1 robot system show the high potential of the realized setup.

Conclusions: Our preclinical and clinical results indicate that the application of the iSYS1 robotic device significantly increases the accuracy and reduces operating time of stereotactic neurosurgical procedures.