A Simple and Sensitive Airflow Sensor for Sleep Studies

睡眠障碍影响着4000多万美国人。白天过度嗜睡是一个主要的健康问题，导致车辆死亡人数增加，工作效率下降。多导睡眠图(PSG)是诊断睡眠障碍的唯一有效方法。PSG依赖于许多生理参数的准确检测。需要监测的重要参数之一是气流。目前，空气流量是通过使用热敏电阻感应呼吸期间的温度波动来间接测量的。许多研究表明，感知压力比感知温度更敏感；它揭示了热敏电阻经常遗漏的微妙但重要的临床信号。研究还表明，基于压力的气流与实际气流相关，提供了更好的定量测量方法。然而，到目前为止，目前的压力读数设备使用鼻插管来读取压力。鼻插管体积大，对患者的侵入性更强，容易凝结，可能会产生伪影。此外，在每次使用的基础上，鼻插管更昂贵。我们建议开发一种新颖而简单的基于压力的气流传感器，它将用尖端集成了灵敏的微机械(MEMS)压力传感器的电缆来取代插管。传感器元件将靠近患者，这将允许更好的信号检测。改进的灵敏度还将消除对尖头的需要，使该设备比套管系统侵入性更小。该设备将有多个传感器，提供单独的鼻部和口腔气流信号。我们将利用已经为许多应用建立的具有成本效益和高灵敏度的MEMS解决方案来生产廉价和快速上市的产品。在第一阶段，我们将使用现有的传感器构建原型，并在工作台和志愿者身上对其进行评估。在第二阶段，传感器和相关电子产品的最终包装将被开发和测试，并获得监管部门的批准。拟议的商业应用：提供该研究潜在商业应用的简要总结。我们估计，该设备目前在美国的市场规模为每年15,000个传感器。这个市场具有巨大的增长潜力。在估计的1200万阻塞性睡眠呼吸暂停综合症患者中，只有100万名患者得到了诊断。这使得大量人口需要PSG，因此对PSG配件(如拟议的设备)的潜在需求很大。由于人们对睡眠影响的认识程度提高，其他睡眠人群也出现了增长。总体而言，睡眠设备市场预计将增长17%。

Sleep disorders affect more than 40 million Americans. Excessive daytime sleepiness is a major health problem contributing to the increasing vehicular fatalities, and reduced work productivity. A polysomnograph (PSG) is the only effective way to diagnose sleep disorders. PSG relies on accurate detection of many physiological parameters. One of the important parameters to monitor is airflow. Currently, airflow is measured indirectly by sensing temperature fluctuations during breathing using thermistors. Many studies showed that sensing pressure, instead of temperature, is more sensitive; it reveals subtle but important clinical signals often missed by thermistors. Studies also showed that pressure-based airflow is correlated to actual airflow offering a better quantitative measure. So far, however, current pressure- based devices use nasal cannula for pressure reading. Nasal cannula are bulky, more intrusive to the patient, susceptible to condensation and can generate artifacts. Also, nasal cannula are more expensive on per use basis. We propose to develop a novel and simple pressure-based airflow sensor that will replace the cannula with a cable having sensitive micromachined (MEMS) pressure sensors integrated at the tip. The sensor elements will be proximal to the patient, which will allow better signal detection. Improved sensitivity will also eliminate the need for prongs making the device less intrusive than cannulae systems. The device will have multiple sensors offering separate nasal and oral airflow signals. We will capitalize on cost efficient and highly sensitive MEMS solutions already established for many applications to produce inexpensive and fast to market product. In Phase I, we will construct prototypes using existing sensors and evaluate them on the bench and on volunteers. In Phase II, final packaging of the sensor and associated electronics will be developed and tested, and regulatory approval obtained. PROPOSED COMMERCIAL APPLICATIONS: Provide a brief summary of the potential commercial applications of the research. We estimate the existing U.S. market size for this device at 15,000 sensors per year. The market has a huge growth potential. Out of the estimated 12 million people who suffer from OSA only 1 million patients are diagnosed. This leaves a large population in need of PSG and therefore creates a large potential demand for PSG accessories such as the proposed device. Other sleep segments are also witnessing growth due to the heightened appreciation of its implications. Overall, the sleep devices market is expected to grow at 17%.