Patient specific modeling of leg compression in the treatment of venous deficiency.

Leg compression is the process of applying external compression forces onto the human leg with stockings or socks, with the purpose of treating venous deficiency, recovering from a sporting competition, or simply as prevention against the economy-class syndrome for transcontinental flights. The objective of this book chapter is to present a computational approach for characterizing the biomechanical effects of compression onto the soft tissues of the leg. The originality of the approach is that it accounts for the inter-individual variability. After introducing the principal medical knowledge about venous deficiency and its treatment by compression therapy, a literature survey about computational biomechanical modelling regarding this topic is presented. The importance of patient-specific modelling is highlighted and the approach that we specifically developed for addressing this issue is further detailed. The main originality concerning the patient-specific numerical modelling is to account for the actual material properties of both the compression stocking and biological soft tissues inside the leg. Suitable identification methods, based on image warping and model updating from MRI scans (for the internal leg tissues), are developed for retrieving these material properties. Eventually, the local pressure induced by compression in the tissues surrounding the veins is determined for different subjects. Perspectives are presented for integrating the effects of compression therapy onto the blood flow itself and for improving the design of compressive garments.