Physical examination courses are an essential part of the education of medical students. The aim of this study was to ascertain the factors influencing students’ motivation and willingness to participate in a physical examination course. Students were asked to complete a questionnaire subdivided into five domains: anthropometric data, religiousness, motivation to take part in physical examination courses, willingness to be physically examined at 11 different body regions by peers or a professional tutor and a field for free text. The questionnaire was completed by 142 medical students. The importance of the examination course was rated 8.7 / 10 points, the score for students’ motivation was 7.8 / 10 points. Willingness to be physically examined ranged from 6 to 100% depending on body part and examiner. Female students were significantly less willing to be examined at sensitive body parts (breast, upper body, groin and the hip joint; p = .003 to < .001), depending on group composition and / or examiner. Strictly religious students showed significantly less willingness to undergo examination of any part of the body except the hand (p = .02 to < .001). Considering BMI, willingness to be examined showed comparable rates for normal weight and under- / overweight students in general (80% vs. 77%). Concerning the composition of the group for physical examination skills courses, students preferred self-assembled over mixed gender and same gender groups. Peer physical examination is a method to improve students’ skills. While motivation to participate in and acceptance of the physical examination course appears to be high, willingness to be examined is low for certain parts of the body, e.g. breast and groin, depending on religiousness, gender and examiner. Examination by a professional medical tutor did not lead to higher acceptance. Most students would prefer to choose their team for physical examination courses themselves rather than be assigned to a group.

In minimally invasive surgery, new flexible instruments enable safer and easier access to difficult-to-reach anatomical regions. However, their introduction into the clinical workflow requires robust replanning, because navigation errors during surgery render initially planned trajectories infeasible. Such replanning requires to regularly solve an expensive two point Boundary Value Problem (BVP) that connects the target pose of the instrument with the currently measured one. We propose a hybrid planning scheme that features both robust and safe replanning. This two step approach first solves the BVP and then transforms the result to circular arcs which fit the motion of our instruments' models. We exploit implicitly defined Bezier splines as a robust method for interpolation in the first step. A novel geometric translation of these splines then provides a convenient solution for movement along circular arcs. We consider two example applications: planning for a drilling unit in temporal bone surgery and guidewires in catheter insertion. Evaluation on real patient data of both temporal bone and aorta show that our proposed hybrid two step approach achieves on average $55\%$ higher replanning rates and provides $31\%$ larger clearance to risk structures, thus improving trajectory quality with regard to clinical safety.

Objective: Navigation systems create a connection between imaging data and intraoperative situs, allowing the surgeon to consistently determine the location of instruments and patient anatomy during the surgical procedure. The best results regarding the target registration error (measurement uncertainty) are normally demonstrated using fiducials. This study aimed at investigating a new registration strategy for an electromagnetic navigation device. Methods: For evaluation of an electromagnetic navigation system and comparison of registration with screw markers and automatic registration, we are calculating the target registration error in the region of the paranasal sinuses/anterior and lateral skull base with the use of an electromagnetic navigation system and intraoperative digital volume tomography (cone-beam computed tomography). We carried out 10 registrations on a head model (total n = 150 measurements) and 10 registrations on 4 temporal bone specimens (total n = 160 measurements). Results: All in all, the automatic registration was easy to perform. For the models that were used, a significant difference between an automatic registration and the registration on fiducials was evident for just a limited number of screws. Furthermore, the observed differences varied in terms of the preferential registration procedure. Conclusion: The automatic registration strategy seems to be an alternative to the established methods in artificial and cadaver models of intraoperative scenarios. Using intraoperative imaging, there is an option to resort to this kind of registration as needed.