White-silicone rubber and copolymer-in-oil blend for ultrasound soft tissue mimicking material

It was estimated that annual cost of measurable medical errors was higher than $17 billion in 2008. Phantoms are objects manufactured using a tissue mimicking material (TMM) and largely used to test protocols and mimic clinical environment for medical training. TMM should reproduce at least one biological property to allow the association with clinical situation. The gel made by the copolymer styrene-ethylene/butylene-styrene (SEBS) in mineral oil previously reported by our group is a stable TMM to ultrasound applications. In this study, we evaluated the acoustical, mechanical and chemical properties of SEBS/white silicone rubber blends for tissue mimicking purpose. The samples were prepared with SEBS at a 10% w/w concentration in mineral oil as solvent. White-silicone rubber was added at proportions of 3, 5, 10 and 15% of solvent mass. Sound speed propagation, acoustic attenuation and Young's modulus were evaluated. Adding white-silicone to the material decreased the speed of sound and increased acoustic attenuation coefficient. B-mode images revealed an increase in the level of ultrasonic scattering. FTIR spectroscopy showed that transmittance for the white silicone rubber fingerprint decreased with silicone concentration. In conclusion, white-silicone rubber can be used as additive to SEBS gel as a tissue mimicking material.