Mathematical modelling for keyhole surgery simulations: a biomechanical model for spleen tissue

There is growing interest in the potential for computer simulations to provide good training materials for abdominal endoscopic or 'keyhole' surgery. This paper describes a preliminary study of the mechanical properties of abdominal (spleen) tissue. We show how experimental force-displacement data can be used to derive a biomechanical model for the tissue as an incompressible, homogeneous, isotropic nonlinear elastic material with an exponential stress-strain law. We also show how the model can be used to predict the response of the tissue to a surgical probe. This involves solving a complicated nonlinear constrained boundary-value problem, and there is a good fit between the computed solution and experimental data.