Regional anaesthesia (RA) has been used increasingly during the past four decades. This is addressed to the perceived advantages of reduced postoperative pain, earlier mobility, shorter hospital stay, and significantly lower costs. The performance of regional anaesthesia necessitates blocking the peripheral nerves by local injection of anaesthetic. Clinically this is achieved by the insertion of the injection needle close to the peripheral nerve, which is visualized with ultrasound and the proximity of the needle to the nerve is assessed with an electric nerve stimulator. However, it is a subtle technique and requires good theoretical, practical, and non-cognitive skills to allow trainees to achieve confidence in performing regional anaesthesia and to keep complications to a minimum. Current training methods for regional anaesthesia include cadavers, video teaching, ultrasound guidance, and simple virtual patient modelling. These techniques have limited capabilities and do not consider individual anatomy. The Virtual Physiological Human (VPH) creates the possibility to generate patient-specific computer models and apply them to RA procedures. The goal of this project is to increase the application, the effectiveness and the success rates of RA and furthermore the diffusion of the method into a broader clinical use through the development of patient-specific VPH models for anaesthesia. We aim at developing two independent but complementary systems, one system for training and one for guidance: a patient-specific Regional Anaesthesia Simulator (RASim) enhanced with ultrasound guidance and a Regional Anaesthesia Assistant (RAAs), which will assist the physicians to localize the nerve during the actual procedure. The RASimAs project will combine both, offering the possibility of training in the regional anaesthesia technique during the training phase of the physician and providing assistance during the clinical application of regional anaesthesia at later stages.