Introduction

Strains and sprains of soft tissues, including tendons and ligaments, are frequently occurring injuries. Musculoskeletal models show great promise in prediction and prevention of these injuries. However, these models rarely account for the viscoelastic properties of ligaments and tendons, much less their failure properties. The purpose of this project was to develop, simplify, and analyze a collagen-distribution model to address these limitations.

Model development

A distribution-moment approximation was applied to an existing partial differential equation model to reduce its computational complexity. The resulting model was equipped with a Voigt model in series, which endowed it with viscoelastic properties in addition to failure properties.

Results

The model was able to reproduce the characteristic toe, linear, and failure regions ubiquitous throughout in-vitro tests on tissue specimens. In addition, it was able to reproduce a tri-phasic creep test consisting of an initial deformation, a steady-state, and failure. Stress-relaxation and hysteresis were also reproducible by the model.

Discussion and conclusion

The ability to reproduce so many characteristics of biological tissues suggests more bio-fidelity was achieved by the reduced model was other currently available models. Future work to further improve its bio-fidelity is proposed for specific tendons and ligaments.

中文翻译：

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基于一维胶原的被动软组织具有粘弹性和破坏的生物力学模型。

介绍

包括肌腱和韧带在内的软组织的应变和扭伤经常发生。肌肉骨骼模型在预测和预防这些损伤方面显示出巨大的希望。但是，这些模型很少考虑韧带和肌腱的粘弹性，更不用说其破坏性能了。该项目的目的是开发，简化和分析胶原蛋白分布模型以解决这些限制。

模型开发

将分布矩近似应用于现有的偏微分方程模型以降低其计算复杂性。所得模型配备了一系列Voigt模型，该模型除了具有破坏特性外，还具有粘弹性。

结果

该模型能够在组织样本的整个体外测试中重现普遍存在的特征趾，线性和破坏区域。此外，它还可以再现由初始变形，稳态和破坏组成的三相蠕变测试。该模型还可以缓解应力松弛和滞后现象。

讨论和结论

再现生物组织如此众多特征的能力表明，与其他当前可用的模型相比，简化模型可实现更多的生物保真度。提出了针对特定肌腱和韧带的进一步改善其生物保真度的未来工作。