Virtual reality training simulations to acquire surgical skills are important for increasing patient safety and save valuable resources, e.g., cadavers, supervision and operating room time. However, as surgery is a craft, simulators must not only provide a high degree of visual realism, but especially a realistic haptic behavior. While such simulators exist for surgeries like laparoscopy or arthroscopy, other surgical fields, especially where large forces need to be exerted, like total hip arthroplasty (THA; implantation of a hip joint protheses), lack realistic VR training simulations. In this paper we present for the first time a novel VR training simulation for the five steps of THA (from femur head resection to stem implantation) with realis-tic haptic feedback. To achieve this, a novel haptic hammering device, an upgraded version of the Virtuose 6D haptic device from Haption, novel algorithms for collision detection, haptic rendering, and material removal are introduced. In a study with 17 surgeons of diverse experience levels, we confirmed the realism, usefulness and usability of our novel methods.

Indirect vision through a mirror, while bi-manually manipulating both the mirror and another tool is a relatively common way to perform operations in various types of surgery. However, learning such psychomotor skills requires extensive training; they are difficult to teach; and they can be quite costly, for instance, for dentistry schools. In order to study the effectiveness of VR simulators for learning these kinds of skills, we developed a simulator for training dental surgery procedures, which supports tracking of eye gaze and tool trajectories (mirror and drill), as well as automated outcome scoring. We carried out a pre-/post-test study in which 30 fifth-year dental students received six training sessions in the access opening stage of the root canal procedure using the simulator. In addition, six experts performed three trials using the simulator. The outcomes of drilling performed on realistic plastic teeth showed a significant learning effect due to the training sessions. Also, students with larger improvements in the simulator tended to improve more in the real-world tests. Analysis of the tracking data revealed novel relationships between several metrics w.r.t. eye gaze and mirror use, and performance and learning effectiveness: high rates of correct mirror placement during active drilling and high continuity of fixation on the tooth are associated with increased skills and increased learning effectiveness. Larger time allocation for tooth inspections using the mirror, i.e., indirect vision, and frequency of inspection are associated with increased learning effectiveness. Our findings suggest that eye tracking can provide valuable insights into student learning gains of bi-manual psychomotor skills, particularly in indirect vision environments.

We present a novel haptic rendering approach to simulate material removal in medical simulations at haptic rates. The core of our method is a new massively-parallel continuous collision detection algorithm in combination with a stable and flexible 6-DOF collision response scheme that combines penalty-based and constraint-based force computation.

We present the first VR training simulator for hip replacement surgeries. We solved the main challenges of this task - high and stable forces during the milling process while simultaneously a very sensitive feedback is required - by using an industrial robot for the force output and the development of a novel massively parallel haptic rendering algorithm with support for material removal.

We present the first VR training simulator for hip replacement surgeries. We solved the main challenges of this task - high and stable forces during the milling process while simultaneously a very sensitive feedback is required - by using an industrial robot for the force output and the development of a novel massively parallel haptic rendering algorithm with support for material removal.