A Study on the Size of Tangible Organ-shaped Controllers for Exploring Medical Data in VR

Virtual reality (VR) is, by nature, excellent in showing spatial relationships, e.g. for viewing medical 3D data. In this work, we propose a VR system to view and manipulate medical 3D images of livers in combination with 3D printed liver models as controllers. We investigate whether users benefit from a controller in the shape of a liver and if the size matters by using three different sizes (50 %, 75 %, 100 %). In a user study with 14 surgeons, we focused on presence, workload and qualitative feedback such as preference. While neither size differences nor the VIVE tracker as control resulted in significant differences, most surgeons preferred the 75 % model. Qualitative results indicate that high similarity of physical and virtual objects regarding shape and a focus on good manageability of the physical object is more important than providing an exact replica in size.