A surgical assistance system for transcatheter aortic valve implantation based on a magic lens concept

In general, minimally invasive procedures are less stressful for the patient. However, the surgeon does not have a clear view of the surgical field. Technical systems could assist the surgeon in orientation based on preoperative images. We developed a surgical assistance system for Transcatheter Aortic Valve Implantation to address these issues. The system is based on a Magic Lens concept. It combines tracking technology and visualization on a mobile display in real-time. A prototype was implemented to demonstrate the context and focus dependent presentation of patient information. The system allowed an intuitive interaction with preoperatively acquired patient data during the intervention. A preliminary user study with seventeen cardiac surgeons was conducted to evaluate the interaction concept and potential acceptance of such a system. The study results indicated the strong potential of the proposed concept and provided important hints for further development of the technique. 1 Introduction The amount of minimally invasive procedures increased significantly in recent years in several clinical disciplines. In cardiac surgery, more than sixteen thousand aortic valve replacements are performed in Germany per year. Approximately thirty percent of the interventions were performed as Transcatheter Aortic Valve Implantation (TAVI) [1, 2]. In general, minimally invasive procedures are less stressful for the patient. However, the surgeon does not have a clear view of the surgical field. Technical systems could assist the surgeon in orientation based on preoperative images. Techniques of Augmented Reality might be used in surgical assistance systems to allow easy interaction with preoperative data in direct relation to the surgical area. We propose a novel surgical assistance system to address these issues with focus on access planning. The clinical use case of TAVI was used to demonstrate the feasibility of the concept. 2 Material and Methods The developed assistance system was based on the concept of a Magic Lens. The Magic Lens Paradigma was published by Bier et al. [3] in 1993 for graphical user interface elements. Later, physical lenses [4] and extension to the Magic Lens concept [5] were proposed. A Magic Lens provides additional information in relation to its position and the object of interest. The visualization of the information basically depends on context and focus. This is common to many Augmented Reality applications using head-mounted displays [6] and video overlays [7]. However they do not provide tac-tile interaction. The surgical situation, the patient and its anatomy were the context of the assistance system. Hence, …