Influence of intermittent compression cuff design on calf deformation: computational results

The intermittent compression of the calf with an external pressure cuff for the prevention of deep vein thrombosis (DVT) is a well established treatment for surgical patients. The exact mechanisms by which DVT is prevented are poorly understood. This study presents a finite element model of calf cross section, based on MR images of calf geometry, to examine the variation in calf deformation during compression with four different cuff types. Cuff pressure distribution is modelled using interface pressures obtained in a volunteer study. The model has been validated against gross calf deformation obtained from MR images of the compressed calf. This validation has illustrated the importance of out-of-plane boundary conditions, material properties and the variation in cuff loading in the axial direction. In the future this model may have merit in determining optimum pressure loading regimes for intermittent pneumatic compression (IPC) cuff design.