骨骼肌的被动生物力学特性与其延展性密切相关，对功能评估、疾病诊断、康复计划制定等均具有重要指导意义，但临床缺少无创、定量评估骨骼肌被动力学特性的方法和指标。本项目针对骨骼肌具有横观各向同性，弹性随肌力变化的特点，基于Hill肌肉力学模型，拟研究声辐射力诱导水平剪切波(SH波)和准垂直剪切波(qSV波)来获取肌纤维被动弹性参数，依托自主研制的“声辐射力-成像”双模超声线阵探头和电子系统，主要研究：①联合测量SH波和qSV波的波速计算肌纤维杨氏模量；②通过超声B-mode图像测量肌纤维长度；③通过杨氏模量-长度序列估计被动弹性系数；④采集动物离体肌肉组织的超声数据，与物理拉伸法进行对比，验证方法的准确性。该项目是前期工作“超声剪切波弹性成像关键技术及应用”的延续和深化，将传统的静态下骨骼肌弹性检测扩展到运动过程中反映弹性变化趋势的力学参数检测，推动超声生物力学检测技术在肌骨系统的创新应用。

The passive elastic properties of human skeletal muscle are closely correlated with its extensibility, and play an important role in motor function, medical diagnosis on muscle injuries and disorders, and in monitoring disease progression and treatment response. However, quantitative, non-invasive assessment of passive elastic properties of individual muscles remains one of the main open challenges in clinical practice. Be aimed at the incompressible transversely isotropic and dynamic material, based on Hill model, this project develops a method for estimating passive elastic properties of muscle fiber, using shear horizontal wave and quasi-shear vertical wave induced by acoustic radiation force. The major researches of this study rely on a self-developed acoustic radiation force-imaging ultrasonic linear array probe and electronic system, include: ①The measurement of Young modulus value of muscle fiber combing SH wave velocity and qSV wave velocity. ②The measurement of length value of muscle fiber; ③ The estimation of passive-elastic coefficient from Young modulus-length curve; ④The verification of the feasibility and effectiveness of this project via in-vitro experiment. This further project is a continuation of preliminary work. It can be anticipated that the accomplishment of this project can provide a precise and practical method of clinic application for musculoskeletal system.