RAPID: Using Smartphones to detect and monitor respiratory symptoms in COVID-19 patients

RAPID：使用智能手机检测和监测 COVID-19 患者的呼吸道症状

• 批准号: 2031977
• 负责人: Tanzeem Choudhury
• 金额: $ 10万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-15 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2031977&HistoricalAwards=false
• 关键词: RAPID; Using; Smartphones; detect; monitor

This project will develop, refine, and evaluate a smartphone-based solution to reliably track changes in blood oxygen saturation (SpO2) and respiration rate and volume. Recent analysis of COVID-19 patients have shown some unusual findings. For example, there is a discordance between the respiratory symptoms and the blood oxygen saturation levels. This can lead to sharp deterioration of patient status without the individual experiencing the usual signs of distress. Existing smartphone solutions do not work in detecting significant drop in blood oxygenation, which is essential to detect whether the person needs to be hospitalized. Accurate in-home tracking of respiratory signals and blood oxygenation levels can help to monitor and follow patients with COVID-19 and identify those who are stable vs. those who are deteriorating.This project will enable two informative, scalable, and cost-effective measurements using smartphones: (i) SpO2 and (ii) respiration rate and volume changes. Although there are many standalone pulse oximeters on the market which are FDA approved and work well (accuracy of ±2%), most people don't have them and are unlikely to buy special purpose devices. Recently, several smartphone and smartwatch based apps have been released that claim to measure oxygen saturation, but they are not reliable. These applications simply use the phone's camera to measure the change in reflection. While these apps can capture pulse reliably, and even capture the blood hemoglobin concentration to some degree, it does not work for oxygen saturation as there are no separate signals to compare oxygenated against deoxygenated hemoglobin. In general, pulse oximetry works by measuring the light absorption in hemoglobin (transdermally) at two different wavelengths (red: 660nm and near-infrared: 940nm). Both of these bands can be found in broadband white LEDs, such as those used for flash on smartphones and can be read by the image sensors (cameras), as they use infrared for distance measurements in photographs. With optical filters attached to the smartphone flash, these two distinct bands can be separated out from the broadband source, captured by the phone's camera, and be used as a pulse oximeter. For monitoring respiration signal/rate, the project will build on the investigators' previous work on opioid overdose detection, which leverages the speakers and microphones of a smartphone to monitor the chest motion of a person in a contactless fashion. At a high level, the smartphone transmits inaudible high-frequency custom sound signals using the device's speaker. These signals are reflected by the subject's chest and recorded using the device's microphones. The chest motion due to breathing causes a change in these reflections as seen by the microphones. These changes can be detected and the respiration signal can be obtained using signal processing algorithms on the smartphone. This system can now be improved to detect changes in respiration rates caused due to the onset of viral infections and difficult breathing conditions like hypoxia.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目将开发、完善和评估一种基于智能手机的解决方案，以可靠地跟踪血氧饱和度（SpO2）、呼吸速率和体积的变化。最近对COVID-19患者的分析显示了一些不寻常的发现。例如，呼吸系统症状与血氧饱和度之间存在不一致。这可能导致患者状态急剧恶化，而个人却没有经历通常的痛苦迹象。现有的智能手机解决方案无法检测血液氧合水平的显著下降，而血液氧合水平对于检测患者是否需要住院至关重要。准确在家跟踪呼吸信号和血氧水平有助于监测和跟踪COVID-19患者，并确定哪些人病情稳定，哪些人病情恶化。该项目将使用智能手机实现两项信息丰富、可扩展且具有成本效益的测量：(i) SpO2和（ii）呼吸速率和体积变化。虽然市场上有许多独立的脉搏血氧仪是FDA批准的，并且工作良好（精度为±2%），但大多数人没有它们，也不太可能购买特殊用途的设备。最近，一些基于智能手机和智能手表的应用程序已经发布，声称可以测量血氧饱和度，但它们并不可靠。这些应用程序只是使用手机的摄像头来测量反射的变化。虽然这些应用程序可以可靠地捕获脉搏，甚至在某种程度上捕获血红蛋白浓度，但它不适用于氧饱和度，因为没有单独的信号来比较含氧和脱氧血红蛋白。一般来说，脉搏血氧仪通过测量血红蛋白（透皮）在两种不同波长（红光：660nm和近红外线：940nm）下的光吸收来工作。这两种波段都可以在宽带白光led中找到，比如那些用于智能手机闪光灯的led，并且可以被图像传感器（相机）读取，因为它们使用红外来测量照片中的距离。通过在智能手机闪光灯上安装光学滤光片，这两个不同的波段可以从宽带信号源中分离出来，由手机摄像头捕捉，并用作脉搏血氧计。为了监测呼吸信号/频率，该项目将建立在研究人员之前的阿片类药物过量检测工作的基础上，该工作利用智能手机的扬声器和麦克风以非接触式方式监测一个人的胸部运动。在高水平上，智能手机使用设备的扬声器传输听不见的高频定制声音信号。这些信号被受试者的胸部反射，并用设备的麦克风记录下来。由于呼吸引起的胸部运动引起了这些反射的变化，就像麦克风看到的那样。这些变化可以被检测到，呼吸信号可以通过智能手机上的信号处理算法获得。这个系统现在可以改进，以检测由于病毒感染和缺氧等呼吸困难情况的发作而引起的呼吸速率变化。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。