Improved Characterization of Soft Tissue Mechanical Properties Using a Combination of Stress Relaxation and Creep

INTRODUCTION Mechanical characterization of articular cartilage, soft tissues and gels is important for biomechanical reference data and for functional assessment of biopsied or engineered tissue. Common techniques include dynamic mechanical spectroscopy [1] and stress relaxation [2], with the latter often favored for technical simplicity. While reliable, stress relaxation measurements of cartilage mechanical properties are still subject to significant uncertainty. Using a limiting solution of the poroelastic governing equations, we have developed an approach which combines creep and stress relaxation to effectively double the amount of data available from soft tissue mechanical characterization experiments with only a small increase in the experimental time required.