The ever improving price-performance ratio of personal computers is making a significant contribution to widening the accessibility of training simulators for a wide variety of medical procedures. High fidelity solutions are becoming more and more sought after. However, the problem of providing realistic soft tissue deformation in real time remains, particularly if haptic interaction is also required. This paper presents a new approach for efficient soft tissue deformation using particle systems to model both structure and haptic properties of anatomy. We are applying this technique to a simulator for interventional radiology procedures, but it can easily be adapted for other medical domains.