Effects of aging on the Biomechanical Properties of Human Vocal Folds

描述(申请人提供)：从2000年到2030年，美国老年人口将增加一倍以上，达到7210万人。声音粗糙和音质下降是无处不在的衰老迹象。声带固有层(LP)的僵硬状态在很大程度上决定了声带的振动特性。硬度是由细胞外基质的结构特性引起的声带LP力学特性的非线性和各向异性决定的。因此，了解LP的力学和微结构特性随年龄的变化可以阐明影响老年人粘膜波、声带振动和嗓音质量的主要原因。这项研究的目标有三个：第一，基于体外发声测量，确定LP机械性能的内在非线性和各向异性，以及它们对音调范围和闭合模式的影响，作为年龄的函数；第二，确定弹性蛋白和胶原材料属性对机械行为的潜在贡献，并描绘这些性能随年龄的变化。

DESCRIPTION (provided by applicant): The population of elderly in the United States will be more than doubled, numbering to 72.1 million, from 2000 to 2030. The roughness of voice and decline of voice quality are ubiquitous signs of aging. The vibratory characteristics of the vocal folds are largely governed by the stiffness conditions in the vocal folds lamina propria (LP). The stiffness is determined by the nonlinearity and anisotropy of vocal fold LP mechanical properties resulting from the structural properties of the extracellular matrix. Therefore, knowledge of alterations in the LP mechanical and microstructural properties with age can elucidate the primary causes affecting mucosal wave, vocal fold vibration and voice quality in elderly. The goal of this research proposal is three-fold: First, to determine the inherent nonlinearity and anisotropy of the LP mechanical properties and their influence on the pitch range and closure pattern, based on in vitro phonation measurements, as a function of age; secondly, to determine the underlying contribution of elastin and collagen material properties to the mechanical behavior, and delineate the alterations in these properties with age.