Ventilation Stethoscope using Hyperpolarized Xenon

描述（由申请方提供）：呼吸机诱导的肺损伤（VILI）是呼吸衰竭重症患者发病和有时死亡的常见原因。的 VILI的类型包括气压伤、创伤、肺不张和生物性创伤。因此，呼吸机设置是在实现充分通气但避免过度压力和过度膨胀或压力太小和过度剪切应力之间的微妙平衡，当呼吸机单元在打开和关闭之间循环时。此外，重症患者通常不能移动到CT扫描仪，这是评估通气是否充分的传统方法。因此，为了最佳地调节ICU中的呼吸机设置，需要一种无创的， 相对便携的设备，可以测量局部通风。为了解决这一需求，在本申请中，我们提出构建便携式通气听诊器（VS）。通气听诊器是一种便携式设备，旨在使用与磁共振成像（MRI）相同的原理测量定量局部通气。与传统的MRI系统不同，该设备是便携式的，体积更小，并且使用单个探头（类似于听诊器）执行局部通气的测量。因此，VS是一种低场（~0.01T）磁共振波谱仪。为了提高灵敏度，将超极化129 μ l气体注入呼吸机输出。这个建议的一个关键方面是便携式连续流动氙激光偏振器的发展，以产生一个稳定的超极化129氙气体源。VS探头将由永磁体组成，该永磁体与射频线圈集成在单个平面结构中，从而使其具有在结构本身外部的磁场均匀性区域，该区域以已知深度投射到肺中。利用该装置，我们建议在健康成年志愿者中演示区域通气的测量。

DESCRIPTION (provided by applicant): Ventilator Induced Lung Injury (VILI) is a common cause of morbidity and sometimes mortality in critically ill patients with respiratory failure. The types of VILI include barotraumas, volutrauma, atelectrauma, and biotrauma. Thus ventilator setting is a delicate balance between achieving sufficient ventilation but avoiding excessive pressure and overdistension or too little pressure and excessive shear stress when ventilatory units cycle between open and closed. In addition, critically ill patients most often cannot be moved to a CT scanner, which is the traditional method for evaluating adequate ventilation. Thus in order to optimally adjust ventilator settings in an ICU, there is a need for a noninvasive, relatively portable device that can measure regional ventilation. To address this need, in this application, we propose building a portable ventilation stethoscope (VS). The Ventilation Stethoscope is a portable device designed to measure quantitative regional ventilation using the same principles as in Magnetic Resonance Imaging (MRI). Unlike the traditional MRI system, the device is portable, smaller, and performs a measurement of regional ventilation with a single probe (similar to a stethoscope). Thus the VS is a low field (~0.01T) magnetic resonance spectrometer. To enhance sensitivity hyperpolarized 129Xe gas will be injected into the ventilator output. A key aspect of this proposal is the development of a portable continuous flow xenon laser polarizer to produce a steady source of hyperpolarized 129Xe gas. The VS probe will consist of permanent magnets integrated with the rf coil into a single planar structure such that it has a region of magnetic field homogeneity external to the structure itself that is projectd into the lung at a known depth. With this device, we propose to demonstrate the measurement of regional ventilation in healthy adult human volunteers.