The State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China.
The State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China.
Ultrasound Med Biol. 2020 Feb;46(2):315-324. doi: 10.1016/j.ultrasmedbio.2019.08.007. Epub 2019 Nov 8.
It is crucial to model skeletal muscles for muscle-centered health care, such as prosthetics. Here we hypothesize that the acoustic non-linearity parameter (B/A) can be utilized to partially represent the contraction state of skeletal muscles. Although previous work commonly measured the B/A value of tissues in vitro, the present study targets the biceps brachii muscle to investigate the relationship between the B/A value and the dynamics of the elbow. Furthermore, it is proposed that a correction method based on the angular spectrum theory be applied in vivo, and the dynamic metrics of the B/A value and its feasibility be verified through an underwater experiment. Seven participants were invited for the in vivo experiment, in which elbow torque and B/A values were measured simultaneously. The non-plane reflection was approximately treated through an integral method, leading to a modified B/A value. Then, linear regression was applied to characterize the B/A-torque relationship, with the calculated coefficient of determination (R) ranging from 0.85-0.93. Experimental results indicate that the modified B/A value of the biceps brachii correlates well with elbow torque. This study not only paves the way to dynamic measurement of the B/A value of skeletal muscles in vivo, but also confirms that B/A can be used as a more comprehensive assessment criterion for muscle functions.
对于以肌肉为中心的医疗保健，如假肢，建立骨骼肌模型至关重要。在这里，我们假设声非线性参数（B/A）可用于部分表示骨骼肌的收缩状态。尽管之前的工作通常在体外测量组织的 B/A 值，但本研究以肱二头肌为目标，研究 B/A 值与肘部动力学之间的关系。此外，提出了一种基于角谱理论的体内校正方法，并通过水下实验验证了 B/A 值的动态指标及其可行性。邀请了 7 名参与者进行体内实验，同时测量了肘部扭矩和 B/A 值。通过积分法对非平面反射进行了近似处理，得到了修正后的 B/A 值。然后，应用线性回归来描述 B/A-扭矩关系，计算得到的确定系数（R）范围为 0.85-0.93。实验结果表明，肱二头肌的修正 B/A 值与肘部扭矩密切相关。本研究不仅为骨骼肌体内 B/A 值的动态测量铺平了道路，还证实了 B/A 可以作为肌肉功能的更全面评估标准。
