Novel neuromechanical measurements of the human upper airway in health and disease

阻塞性睡眠呼吸暂停（OSA）是一种常见的疾病，在睡眠过程中上呼吸道反复塌陷，导致血液中的氧浓度下降，二氧化碳上升，并且人为了重新建立足够的氧气供应而醒来。阻塞性睡眠呼吸暂停的后果包括白天嗜睡增加，事故风险增加，心血管疾病风险增加。它最常见于中年男性，但也见于更广泛的人群。阻塞性睡眠呼吸暂停与肥胖、特定的上气道形状和面部结构有关。这些解剖因素可以在清醒时得到补偿，但睡眠时上呼吸道周围肌肉活动不足会增加气道塌陷的易感性。当肌肉无法承受气道内的低压而塌陷，阻塞气道时，就会发生气道塌陷。该项目将测量健康人群和OSA患者气道周围肌肉的僵硬度和运动，以确定这些因素如何影响气道塌陷。我们将使用两种新的非侵入性磁共振成像（MRI）技术，MR弹性成像和MR标记，这将使我们能够量化气道刚度或弹性及其运动（变形）。这将是人类上呼吸道弹性和变形的首次直接测量。我们还将测量各种治疗方法，如CPAP治疗和下颌骨推进如何影响气道弹性和变形，以便更好地了解其机制。这也可以解释为什么有些病人不能从这些疗法中获益。这些研究可能会导致新的诊断和治疗方式，以及对人类气道塌陷的基本机制获得重要的见解。

Obstructive sleep apnea (OSA) is a common condition, in which the upper airway repeatedly collapses during sleep, causing the oxygen concentration in the blood to drop, carbon dioxide to rise, and the person to arouse in order to re-establish adequate oxygen supply. Consequences of OSA include increased daytime sleepiness, increased risk of accidents, and increased risk of cardiovascular diseases. It most commonly affects middle-aged males, but is also seen in the broader population. OSA is associated with obesity and specific shapes of the upper airway and facial structure. These anatomical factors can be compensated for while awake but inadequate activity of the muscles surrounding the upper airway during sleep contributes to an increased predisposition of the airway to collapse. Airway collapse occurs when the muscles are unable to withstand the low pressures in the airway and collapse, obstructing the airway. This project will measure the stiffness and motion of the muscles surrounding the airway, in healthy people and those with OSA, to determine how these influence airway collapsibility. We will use two novel non-invasive Magnetic Resonance Imaging (MRI) techniques, MR Elastography, and MR tagging which will allow us to quantify the airway stiffness, or elasticity, and its motion (deformation). These will be the first direct measurements of the upper airway elasticity and deformation in humans. We will also measure how various treatments, such as CPAP therapy and mandibular advancement affect airway elasticity and deformation, so that their mechanisms can be better understood. This may also explain why some patients do not benefit from these therapies. These studies may lead to new diagnostic and treatment modalities, as well as gaining important insights into the basic mechanisms of airway collapse in humans.