In this paper we propose a new framework for deformation modelling based on a combined mass spring and tensional integrity method. The synergy between balanced tension and compression components offered by the tensegrity model helps the deforming organ retain its shape more consistently. We chose the diaphragm as our test object given its heterogeneous composition (muscle and tendon) and its importance in radiotherapy and other interventional procedures. Diaphragm motion can significantly influence surrounding organs such as lungs and liver. Our system permits the control of simulated diaphragm motion and deformation by at least two independent parameters.