SoundTrak: A Data Acquisition and Analysis System for OSDB

描述（由申请人提供）：阻塞性睡眠呼吸障碍（OSDB）在儿童和成人中都很常见，并且在所有年龄段都被认为具有实质性的健康相关后果。实验室多导睡眠图（PSG）是诊断OSDB的金标准，但该程序并非没有问题。多导睡眠图研究是复杂的，侵入性的，昂贵的，并不是普遍可用的，并且需要在睡眠实验室过夜。此外，用于检测空气流量，特别是口腔空气流量的传统信号是定性的，这使得难以精确量化OSDB。此外，在儿童中，离散性呼吸暂停或呼吸不足通常不存在；相反，长时间的高呼吸/高阻力呼吸需要非常低的食道压力来在狭窄的气道中产生空气。这种高阻力呼吸很难用传统的PSG检测到。该团队发表的研究表明：(1)频率在2-10 kHz范围内的高频吸气声（HFIS）是OSDB发生的标志；(2) HFIS是在睡眠时上呼吸道变窄时产生的，充当谐振腔（符合圆柱形管道中声音共振的物理特性）。需要强调的是，这些HFIS不同于描述典型打鼾的低频（< 2 kHz）声音。HFIS强度可以定量分析，确定气道狭窄程度和气道压力梯度。Barron Associates和弗吉尼亚大学（UVA）正在开发SoundTrak系统，这是一种低成本的睡眠监视器，可用于个人家庭环境，无创，符合人体工程学，并自动获取和分析与OSDB相关的HFIS数据。SoundTrak系统将通过一个麦克风和一个小型、高度便携的计算基站收集低频和高频声音数据。呼吸运动将使用无线胸廓带进行测量，从而可以检测到灵感，并将患者的睡眠声音与其他来源区分开来。胸带还将收集无线心电图（ECG）、身体姿势、活动和皮肤温度数据，并将这些信息实时传递到SoundTrak基站。SoundTrak系统将包括一个脉搏血氧仪来报告氧饱和度水平，这通常有助于医生评估OSDB。如本文所述，SoundTrak系统将比目前可用的家庭睡眠监测技术提供许多优势。第一阶段的研究，以及该团队最近发表的其他工作，证明了HFIS和胸部监测作为PSG诊断OSDB的替代方法的可行性。该报告的中心目标是在20名儿童和80名成人中证明HFIS家庭研究的可行性。传统的夜间实验室PSG将与基于易于使用、无创的SoundTrak II期原型系统的家庭睡眠研究进行比较。

DESCRIPTION (provided by applicant): Obstructive sleep-disordered breathing (OSDB) is common in both children and adults and is recognized as having substantial health-related consequences at all ages. Laboratory polysomnography (PSG) is the gold standard for diagnosing OSDB, but the procedure is not without problems. Polysomnographic studies are complex, invasive, expensive, not universally available, and require an overnight stay in a sleep laboratory. Additionally, conventional signals used to detect air ow, especially oral air ow, are qualitative, making it difficult to precisely quantify OSDB. Furthermore, in children, discrete apneas or hypopneas are often not present; instead, there are long periods with high-e ort/high-resistance breathing requiring very low esophageal pressures to generate air ow in a narrowed airway. This high-resistance breathing is difficult to detect using conventional PSG. Published research by the proposing team has demonstrated that: (1) high-frequency inspiratory sounds (HFIS) in the frequency range of 2-10 kHz are a marker for the occurrence of OSDB; and (2) HFIS are generated when the upper airway is narrowed during sleep and acts as a resonant chamber (in agreement with the physics of sound resonance in a cylindrical pipe). It is emphasized that these HFIS are different from the low-frequency (< 2 kHz) sounds that describe typical snoring. HFIS intensity can be analyzed quantitatively to determine the degree of airway narrowing and the pressure gradient across the airway. Barron Associates and the University of Virginia (UVA) are developing the SoundTrak system, a low-cost sleep monitor for use in individuals' home environments to noninvasively, ergonomically, and automatically acquire and analyze HFIS data pertaining to OSDB. The SoundTrak system will collect low- and high-frequency sound data via a microphone and a small, highly-portable computing base station. Breathing movements will be measured using a wireless thoracic band, enabling inspirations to be detected and the patient's sleep sounds to be discriminated from other sources. The thoracic band will also collect wireless electrocardiogram (ECG), body posture, activity, and skin temperature data, and relay that information in real time to the SoundTrak base station. The SoundTrak system will include a pulse oximeter to report oxygen saturation levels, which are often helpful to, and expected by, physicians assessing OSDB. The SoundTrak system will provide many advantages over currently available home sleep monitoring technologies, as is described herein. The Phase I effort, along with other recent, published work by the proposing team, demonstrated the feasibility of using HFIS and thoracic monitoring as an alternative to PSG for diagnosing OSDB. The central goal of the proposed e ort is to demonstrate the viability of in-home HFIS studies in 20 children and 80 adults. Traditional overnight laboratory PSG will be compared with in-home sleep studies based on the easy-to-use, noninvasive Phase II prototype SoundTrak system.