MECHANICAL BLOOD-TISSUE INTERACTION IN CONTRACTING MUSCLES - A MODEL STUDY

A finite element (FE) model of blood perfused biological tissue has be en developed. Blood perfusion is described by fluid flow through a ser ies of 5 intercommunicating vascular compartments that are embedded in the tissue. Each compartment is characterized by a blood flow permeab ility tensor, blood volume fraction and vessel compliance. Local non-l inear relationships between intra-extra vascular pressure difference a nd blood volume fraction, and between blood volume fraction and the pe rmeability tensor, are included in the FE model. To test the implement ation of these non-linear relations, FE results of blood perfusion in a piece of tissue that is subject to increased intramuscular pressure, are compared to results that are calculated with a lumped parameter ( LP) model of blood perfusion. FE simulation of blood flow through a co ntracting rat calf muscle is performed. The FE model used in this simu lation contains a transversely isotropic, non-linearly elastic descrip tion of deforming muscle tissue, in which local contraction stress is prescribed as a function of time. FE results of muscle tension, total arterial inflow and total venous outflow of the muscle during contract ion, correspond to experimental results of an isometrically and tetani cally contracting rat calf muscle, (C) 1998 Elsevier Science Ltd. All rights reserved.