User-interaction of a semiautomatic trepanation system

Abstract

During trepanation, a neurosurgical procedure for opening the skull, the protection of the underlying dura mater and a minimized loss of bone are major concerns. A concept for a novel trepanation system has been developed in order to open the skull less invasively and more safely. This trepanation system is based on a soft tissue preserving cutting tool and an autonomous control of the cutting depth. In this approach a semiautomatic instrument is envisioned, that is manually maneuvered by the surgeon. The cutting depth is adapted automatically by the control system corresponding to the actual thickness of the skull bone. This synergistic control concept combines the computer-related accuracy with the surgeon's know-how and cognitive capabilities. During the complex user interaction between surgeon and trepanation system a high level of safety has to be assured due to the potential risk related to neurosurgical procedures. Therefore we have introduced a usability engineering process based on an initial risk analysis and a model-based usability evaluation tool (mAIXuse) for further analysis of the process, particularly considering the human-machine-interaction. Furthermore a specific safety strategy has been developed. The conducted investigations enable the developers to identify and understand each single process step, in which misinformation or non-specific commands may be given. By using these methods comprehensive safety requirements concerning the user-interface for a semiautomatic neurosurgical device have been identified. The proposed concept will be evaluated in further usability tests with real prototypes.