Characterizing exhaled airflow from breathing and talking
Characterizing exhaled airflow from breathing and talking
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DOI：
10.1111/j.1600-0668.2009.00623.x
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发表时间：
2010-02-01
期刊：
影响因子：
5.8
通讯作者：
Chen, Qingyan
中科院分区：
文献类型：
--
作者：
Gupta, Jitendra K.;Lin, Chao-Hsin;Chen, Qingyan
受感染的人呼出的空气是传染性病毒的主要来源之一.呼出的空气来自呼吸活动，如咳嗽，打喷嚏，呼吸和说话。关于呼出气流的热流体特性的准确信息对于预测传染病传播是重要的。本研究发展了一个源模型，以提供从呼吸和说话过程中呼出的空气的热流体条件。源模型是一组方程，这些方程是从对人类受试者的流速、流动方向和口/鼻开口面积的测量中获得的。据发现，随时间的呼出流量可以表示为一个正弦函数的呼吸和一个常数的谈话。可以通过受试者的生理参数来计算流速。呼气射流的方向在受试者之间没有太大变化，并且口/鼻开口的面积可以被认为是恒定的。虽然口/鼻开口的大小在受试者之间变化，但它们与受试者的生理参数无关。如果结合适当的病毒和飞沫分布信息，该模型可以用来描述疾病源，由于呼吸和talking.Practical ImplicationsAccurate预测空气传播疾病的传播，和感染的易发区，可以帮助识别和实施的控制策略。近年来，计算流体动力学（CFD）已成为预测疾病传播的有力工具。通过这些CFD模拟准确预测传播需要关于传染性病毒的源和汇以及这些病毒的传播模型的信息。受感染的人呼出的空气是疾病病毒的主要来源之一。在本研究中，对人类受试者进行流量测量，以建立呼吸和说话过程中呼气和吸气的流量边界条件模型。
P>The exhaled air of infected humans is one of the prime sources of contagious viruses. The exhaled air comes from respiratory events such as the coughing, sneezing, breathing and talking. Accurate information on the thermo-fluid characteristics of the exhaled airflow can be important for prediction of infectious disease transmission. The present study developed a source model to provide the thermo-fluid conditions of the exhaled air from the breathing and talking processes. The source model is a set of equations obtained from the measurements of the flow rate, flow direction, and area of mouth/nose opening with human subjects. It was found that the exhaled flow rate over time can be represented as a sinusoidal function for breathing and a constant for talking. The flow rates can be calculated by physiological parameters of a subject. The direction of the exhalation jet did not vary much between subjects and the area of mouth/nose opening could be regarded as a constant. Though the mouth/nose opening size varied among subjects, they were not correlated with the physiological parameters of the subjects. If combined with appropriate virus and droplet distribution information, the model can be used to describe the disease source due to breathing and talking.Practical ImplicationsAccurate prediction of airborne disease transmission, and the infection prone zones, can aid in identifying and implementing the control strategies. With the recent advancements, Computational Fluid Dynamics (CFD) has become a powerful tool in predicting the disease transmission. Accurate prediction of the transmission by these CFD simulations requires information on sources and sinks of infectious viruses and models for dispersion of these viruses. The exhaled air of an infected human is one of the prime sources of disease viruses. In the present study, measurements of the flow were conducted on human subjects to develop models for the flow boundary conditions for the exhalation and inhalation during breathing and talking.