Biomechanical effects of hydration in vocal fold tissues
Biomechanical effects of hydration in vocal fold tissues
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DOI：
10.1067/mhn.2002.124936
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发表时间：
2002-05-01
影响因子：
3.4
通讯作者：
Tayama, N
中科院分区：
文献类型：
--
作者：
Chan, RW;Tayama, N
目的：经常有假设，但很少有经验支持，即声带水合作用通过介导声带组织流变学的变化来影响声音的产生。为了验证这一假设，我们在本研究中试图量化水合作用对体外声带组织粘弹性剪切特性的影响。研究设计：通过等渗、高渗和低渗溶液的顺序孵育，诱导6只切除的犬喉部水化（脱水和再水化）的渗透变化。用扭转流变仪测量声带黏膜（固有层）弹性剪切模量（G′）、动态黏度（eta′）和阻尼比随频率（0.01 ~ 15 Hz）的变化。结果：声带组织硬度（G′）和粘度（eta）在渗透诱导脱水时显著增加（4 ~ 7倍），而在诱导补液时则下降22% ~ 38%。阻尼比（zeta）也随脱水而增加，随补液而减少，但在所有频率下检测到的差异均无统计学意义。结论：这些发现支持了长期以来的假设，即水合作用通过改变组织流变学（或粘弹性）特性来影响声带振动。我们的研究结果证明了水合作用在声带组织中的生物力学重要性，并表明水合作用可能潜在地改善声带病变中液体平衡紊乱的发声生物力学。
OBJECTIVE: It has often been hypothesized, with little empirical support, that vocal fold hydration affects voice production by mediating changes in vocal fold tissue rheology. To test this hypothesis, we attempted in this study to quantify the effects of hydration on the viscoelastic shear properties of vocal fold tissues in vitro.STUDY DESIGN: Osmotic changes in hydration (dehydration and rehydration) of 6 excised canine larynges were induced by sequential incubation of the tissues in isotonic, hypertonic, and hypotonic solutions. Elastic shear modulus (G'), dynamic viscosity eta' and the damping ratio of the vocal fold mucosa (lamina propria) were measured as a function of frequency (0.01 to 15 Hz) with a torsional rheometer.RESULTS: Vocal fold tissue stiffness (G') and viscosity (eta) increased significantly (by 4 to 7 times) with the osmotically induced dehydration, whereas they decreased by 22% to 38% on the induced rehydration. Damping ratio (zeta) also increased with dehydration and decreased with rehydration, but the detected differences were not statistically significant at all frequencies.CONCLUSION: These findings support the long-standing hypothesis that hydration affects vocal fold vibration by altering tissue rheologic (or viscoelastic) properties.SIGNIFICANCE. Our results demonstrated the biomechanical importance of hydration in vocal fold tissues and suggested that hydration approaches may potentially improve the biomechanics of phonation in vocal fold lesions involving disordered fluid balance.