Mapping the biomechanical properties of the sub-glottal region of the human vocal tract

发声，或者说我们说话的能力，来自于通过声带（通常称为声带）有控制地呼出空气的过程。这会导致声带振动，频率可以由我们的声带肌肉控制。由此产生的气流现在被调节并进入我们的“声道”，也就是我们的嘴。然后，我们通过肌肉控制舌头、嘴唇和其他声道特征，将经过调制的气流形成声音。因此，发声的起点是我们声带的振荡。当我们呼气时，流动的空气会产生压降；这反过来又导致这些软组织上升，直到它们相遇。当完全闭合发生时，气流停止，气压恢复正常，导致焦点褶皱再次回落。正是这种循环，以可听到的频率重复，产生了最初的调制气流，我们形成了声音。这个过程被称为肌弹性循环；首先由Ingo Titze描述。虽然声道的显像很容易在声道上方实现，但很少有关于声道下方低压影响的发表数据。最近的研究提供了强有力的证据表明，在声门下区域形成涡流，这将通过减少声带下方的气压来帮助关闭声带。我们最近发表的研究使用了我们在威斯康星医学中心的合作伙伴获得的数据，这些数据表明声门下粘膜的弹性特性是非线性的，因此它们在低压下的变形会导致漏斗效应，不如声带。这种可变变形可以为涡旋理论提供支持。这项研究是用猪的喉部进行的。汉堡大学为我们提供了使用切除的人类供体喉部重复这项研究的机会。本OTG的目的是建立并使共同监督博士研究，该研究将测量和绘制人体组织中声门下粘膜的弹性特性。这些数据将提供给其他国际团队，他们正在积极研究声道空气动力学的重要性，以及它如何影响我们的发声能力。我们将开发数学模型来解释测量的数据，并确定它是否支持我们的理论，即声带下方粘膜的变形导致漏斗形状，从而促进涡流的产生。如果我们的理论是正确的，那么它就表明了这个区域在赋予我们说话能力方面的重要性。为了使拨款的成本效益最大化，我们亦会进行创新的激光斑点皮肤分析装置的试验。这是为了研究激光斑点是否可以用于检测皮肤病变（例如黑色素瘤）。我们将对切除的供体喉部进行一系列实验，以确定声外科医生是否也可以利用激光斑点来检测从表面上看不见的声带组织损伤。如果英国大学的研究取得成功，其他国际研究机构也表示有兴趣将激光散斑技术应用于新的研究领域。

Phonation, or our ability to speak, arises from the process of delivering a controlled exhalation of air across the vocal folds (often know as vocal cords). This causes the vocal folds to vibrate, at a frequency that can be controlled by our vocal muscles. The resultant airflow is now modulated and passes into our 'vocal tract', which is in effect our mouth. We then form the modulated air flow into sounds by muscular control of our tongue, lip and other vocal tract features.The starting point for phonation therefore is the oscillation of our vocal folds. As we exhale, the moving passage of air creates a pressure drop; this in turn causes these soft tissues to rise up, until they meet. When full closure occurs the airflow ceases, and the air pressure returns to normal, causing the focal folds to fall back again. It is this cycle, repeated at audible frequencies that creates the initial modulated airflow, that we form into sounds. This process is known as the myoelastic cycle; which was first described by Ingo Titze.Whilst visualisation of the vocal tract is readily achievable superior to the vocal folds, there is very little published data on the impact of low pressure inferior to vocal folds. Recent research has presented strong evidence that vortices form in the sub-glottal region, which will inherently aid closure by reducing the air pressure below the vocal folds.Our recently published work, using data obtained with our partners at Wisconsin Medical Centers presented data that indicated that the elastic properties of the sub-glottal mucosa were non-linear - such that their deformation under low pressure would cause a funnel effect inferior to the vocal folds. This variable deformation could offer support for the vortex theory. The study was carried out using porcine larynges. UKE Hamburg have offered us the opportunity to repeat this study using excised human donor larynges. The purpose of this OTG is to establish and enable the co-supervision of a Dotoral study that will measure and map the elastic properties of the sub-glottal mucosa in human tissue. This data will be made available to other international teams who are actively examining the importance of the aerodynamics of the vocal tract, and how it impacts on our ability to phonate. We will develop mathematical models to explain the data that is measured, and determine if it does support our theory that deformation of the mucosa below the vocal folds results in a funnel shape that promotes the creation of vortices. If our theory is correct then it indicates the importance of this region in giving us the ability to speak.In order to maximise the cost effectiveness of the grant we will also carry out trials of our innovative laser speckle skin analysis device. This has been developed to investigate if laser speckle can be used to detect lesions in skin (e.g. melanoma). We will carry out a series of experiments with excised donor human larynges to determine if laser speckle could also be deployed by phonosurgeons to detect tissue damage in vocal folds that is not visible from the surface. Other international research institutions have expressed interest in applying the laser speckle technique in new areas of research if the UKE study is successful.