The Relationship between Vortices, Acoustics, and Vibration in Vocal Fold Assymet

描述（由申请人提供）：许多声音障碍以声带结构不对称为特征，如声带左右位置、高度、长度或僵硬度的差异（如单侧声带瘫瘫、麻痹、声带息肉、声带瘢痕等）。当不对称是轻微的，目前的治疗对大多数患者是有效的。然而，当不对称显著或多重时，结果就更不确定了。这些患者代表着一个重要的健康问题，因为他们声音障碍的严重程度严重影响着他们的身体、心理和经济。在任何领域，关于干预策略的临床决策取决于临床结果数据和对潜在机制的理解的结合。对于这些患者来说，由于临床数据有限，而且由于问题非常复杂，因此对结构不对称如何影响声带振动和声音产生的科学理解尤为重要。长期以来，人们一直认为喉气流中存在旋涡或旋转运动区域，但其相关性尚不清楚。利用工程领域成熟的实验和理论方法，我们发现了证据，证明垂直结构在声带不对称的情况下特别相关。在之前的工作中，我们的团队得到了主要研究者K-8基金的支持，在切除的犬喉部测量了发声气流的速度场，对量化涡旋特别感兴趣。我们完成的研究（Khosla等人，2007年，2008年和2009年；Murugappan， Khosla等人，2009年）为该应用的总体假设提供了支持基础，即：声门气流包含某些对声学有重大贡献的垂直结构；在某些喉部疾病中，这些螺旋结构会减少或消失。正是这些涡流的改变和/或抑制导致了异常的声音产生。最有效地恢复特定旋涡的治疗将有最好的语音效果。为了检验中心假设，我们建议围绕以下具体目标组织我们的研究。切除的狗和人的喉部将用于所有目的。具体目标1 -使用计算和验证切除半喉模型，表征涡旋和组织弹性对声带振动和声学的影响。特定目标2 -漩涡，组织弹性，声带振动和声学将被测量为不同的功能，临床相关的结构不对称。具体目标3：单侧声带麻痹的单次手术或以下手术组合后，将测量结构不对称、振动不对称和声学的变化：甲状腺成形术1型、内收鹰嘴固定术和环甲半脱位。

DESCRIPTION (provided by applicant): Many voice disorders feature structural vocal fold asymmetries, such as a difference in vocal fold left-right position, height, length or stiffness (e.g. unilateral vocal fold paresis and paralysis, vocal fold polyps, vocal fold scarring, etc.). When the asymmetries are mild, present therapies are effective for most patients. However, when the asymmetries are significant or multiple, outcomes are more uncertain. Such patients represent an important health problem, because the severity of their voice disorder significantly affects them physically, psychologically and economically. In any field, clinical decision-making about intervention strategies depends on a combination of clinical outcome data and the understanding of underlying mechanisms. For these patients, both because clinical data are limited and because the problems are so complex, scientific understanding of how structural asymmetries affect vocal fold vibration and voice production is particularly important. It has long been acknowledged that vortices, or areas of rotational motion, occur in the laryngeal airflow, but their relevance has not been clear. Using well-established experimental and theoretical approaches from engineering, we have found evidence that vortical structures are particularly relevant in cases of vocal fold asymmetries. In this previous work, supported by a K-8 grant to the principal investigator, our team has measured velocity fields of phonatory airflow in excised canine larynges, with particular interest in quantifying vortices. Our completed studies (Khosla et al., 2007, 2008a and 2009; Murugappan, Khosla et al., 2009) provide a supportive foundation to the overarching hypothesis of this application, which is: glottal airflow contains certain vortical structures that significantly contribute to the acoustics; and that in certain laryngeal pathologies, these vortical structures are reduced or eliminated. It is the modification and/or suppression of these vortices that contribute to abnormal voice production. Treatments that most effectively restore specific vortices will have the best voice outcomes. In order to test the central hypothesis, we propose to organize our study around the following specific aims. Excised canine and human larynges will be used for all aims. Specific Aim 1 - Using computational and validated excised hemilarynx models, characterize the effects of vortices and tissue elasticity on vocal fold vibration and acoustics. Specific Aim 2 - Vortices, tissue elasticity, vocal fold vibration and acoustics will be measured as functions of different, clinically relevant structural asymmetries. Specific Aim 3 -The change in structural asymmetries, vibratory asymmetries and acoustics will be measured after a single procedure or a combination of the following procedures for unilateral vocal fold paralysis: Thyroplasty Type 1, Adduction Arytenopexy and Cricothyroid Subluxation. PUBLIC HEALTH RELEVANCE: The results of the proposed research will provide an approach to clinically study patients with vocal fold asymmetry. Looking forward, the study of phonation at this resolution will synergize well with advancing technologies in laryngeal imaging, such as videokymography (Svec et al) and high speed videography (Delyiski) as available clinical technology allows for more precise and reliable identification of asymmetries. The findings will have far reaching impact in laryngology as the results may be applicable to other conditions in the larynx that result in vocal fold asymmetries , such as vocal fold scarring and vocal fold sulcus. These results will have positive impact, since the new knowledge will result in improved diagnostic and clinical techniques that could not be otherwise developed.