Modeling and Simulation of a Human Shoulder for Interactive Medical Applications

Human joints, such as the shoulder, present intricate connections of anatomical elements such as bones, muscles, tendons, ligaments, and fat. The nature and arrangement of the various structures in the shoulder impose two main difficulties for interactive simulation: a large diversity of mechanical properties, ranging from hard bone to soft fat tissue, and complex contact situations. In this paper, we present a combination of representations, simulation methodology, and algorithms, which, altogether, provide the proper balance between simulation quality and performance for interactive medical applications. Unified representations for all dynamic objects and their dynamic state allow us to define coupling constraints and contact constraints in a general way. As a result, all dynamic objects can be simulated at once in a unified manner. We show the application of our algorithm to shoulder simulation in two medical settings: virtual arthroscopy and physiotherapy palpation.