Soft tissue simulation is an important technique in many biomedical modelling applications. While applications for investigating the functioning of organs do require a physically correct mathematical model, other tasks, such as virtual surgery simulations for training purposes, put a bigger emphasis on speed, ease of use, and a large variety of arbitrary interaction. In such applications a plausible, physically not accurate technique is often sufficient. We have investigated the use of meshless deformation based on shape matching for soft tissue simulation and we implemented several improvements which make the simulation more accurate and stable. Novel interaction techniques such as fast, interactive cutting, pushing and picking are introduced. The method is very efficient, easily implemented, and can be integrated into graphics and game engines, but has restrictions in the range of simulated objects.