The acoustic properties of ultrasound phantom materials have always been important, but with new applications interrogating tissue mechanical properties, viscoelasticity has also become an interesting feature to consider. Along with Young's modulus, the viscous component of tissue is affected by certain diseases and can therefore be used as a biomarker. Furthermore, viscoelasticity varies between tissue types and individuals, and therefore it would be useful with a phantom material that reflects this physiological range. Here we describe a gel for ultrasound imaging with a range of mechanical properties given by mixing different ratios of two oil-based gels, clear ballistic and styrene–ethylene/butylene–styrene (SEBS). The gels were mixed in five different proportions, ranging from 0–100% of either gel. For each of the gel compositions, we measured time of flight to determine speed of sound, narrowband ultrasound transmission for attenuation, stress–relaxation for viscoelasticity, mass and volume. Analysis of the stress–relaxation data using the generalized Maxwell model suggests that the material can be described by five parameters, E₀, E₁, E₂, η₁ and η₂, and that each of these parameters decreases as more SEBS is incorporated into the mixed material. Instantaneous Young's modulus (the sum of E₀, E₁ and E₂ in our model) ranges between 49 and 117 kPa for the different ratios, similar to values reported for cancerous tissue. Despite the large span of obtainable mechanical properties, speed of sound is relatively constant regardless of composition, with mean value estimates (± 95 % CI) between 1438 ± 9 and 1455 ± 3 m/s for pure and mixed gels. This was attributed to a variation in density and Poisson's ratio, following from the relation linking them to speed of sound and elasticity. Furthermore, both speed of sound and attenuation were within a suitable range for ultrasound phantoms. Combining this ballistic gel with SEBS copolymer in oil allows for control of mechanical properties, both elastic and viscous as evaluated by the material model. Furthermore, it does so without compromising ease of use, longevity and safety of the pre-made gel.

超声体模材料的声学特性一直很重要，但随着新应用询问组织力学特性，粘弹性也成为一个需要考虑的有趣特征。与杨氏模量一起，组织的粘性成分会受到某些疾病的影响，因此可以用作生物标志物。此外，粘弹性因组织类型和个体而异，因此它对于反映该生理范围的体模材料非常有用。在这里，我们描述了一种用于超声成像的凝胶，该凝胶具有一系列机械性能，通过混合不同比例的两种油基凝胶、透明弹道凝胶和苯乙烯-乙烯/丁烯-苯乙烯 (SEBS) 获得。凝胶以五种不同的比例混合，每一种凝胶的比例为 0-100%。对于每种凝胶组合物，我们测量了飞行时间以确定声速、用于衰减的窄带超声传输、用于粘弹性、质量和体积的应力松弛。使用广义麦克斯韦模型分析应力松弛数据表明材料可以用五个参数来描述，E ₀、E ₁、E ₂、η ₁和η ₂，并且这些参数中的每一个随着更多的SEBS被结合到混合材料中而降低。瞬时杨氏模量（E ₀、E ₁和E _{2 之和}在我们的模型中）不同比率的范围在 49 到 117 kPa 之间，类似于癌组织报告的值。尽管可获得的机械性能跨度很大，但无论成分如何，声速都相对恒定，纯凝胶和混合凝胶的平均值估计值 (± 95 % CI) 介于 1438 ± 9 和 1455 ± 3 m/s 之间。这归因于密度和泊松比的变化，根据将它们与声速和弹性联系起来的关系。此外，声速和衰减都在超声体模的合适范围内。将这种防弹凝胶与油中的 SEBS 共聚物相结合，可以控制由材料模型评估的弹性和粘性机械性能。此外，它不会影响预制凝胶的易用性、使用寿命和安全性。