Mechanical characterisation of an organic phantom candidate for breast tissue

Abstract

The aim of this study is to analyse the mechanical properties of agarose, which can be used as a mechanical phantom for breast tissues. In general, tissue mimicking materials may be used to achieve a better understanding of the structure and properties of tissues and organs; this work shares these objectives. The phantom can be used as a tissue surrogate with realistic mechanical behaviour for biomechanical applications. To validate agarose as a suitable mechanical phantom for breast tissues, indentation tests were performed in homogeneous, rectangular agarose blocks. Blocks with different agarose concentrations were moulded and tested. An estimation of the material stiffness was then compared with experimental data on different breast tissues’ types found in literature. The phantom stiffness increased consistently with agarose concentration and stress. The results show that agarose-based mechanical phantoms of stiffer tissues require higher agarose concentrations (0.5% and 0.6%). In contrast, normal tissues can be mimicked with 0.3% and 0.4% of agarose. In addition, it was observed that preconditioning affects the mechanical properties of the gel, as it had already been shown in literature for breast tissues.