基于PIV技术的人体上呼吸道流场测量实验装置的构建

目的针对人体上呼吸道气流运动形成涡结构、流动分流、二次流等特点，研制基于粒子图像测速（particle image velocimetry, PIV）技术的人体上呼吸道流场测量实验装置，为开展人体上呼吸道流场特性实验研究提供平台。方法 基于完整人体上呼吸道医学扫描图像制备透明的实物模型，通过选择合适的气路系统，结合二维PIV系统搭建整套实验装置，并利用该装置对人体上呼吸道流场速度进行初步实验,将实验结果和数值仿真结果进行对比。结果呼吸流量为30 L/min稳态呼吸模式下,实验装置测得的气流在口腔上部有涡结构的形成，口腔下部贴近舌苔上部及口腔中部的气流速度较高，其他部位气流速度较低，与数值仿真结果较为一致。结论 基于PIV技术的人体上呼吸道流场测量实验装置合理可行，运行可靠，可用于人体上呼吸道内气流组织形式和涡量分布等测量，并能够实现对数值仿真的验证。

Experimental apparatus for measuring flow field of human upper respiratory tract with PIV technology

Objective To develop a measurement device and provide a platform for researching the characteristics of human upper respiratory tract flow field based on PIV (particle image velocimetry) technology with respect to the characteristics that human upper respiratory tract flow may form the vortex structure, flow shunt and secondary flow. Methods A transparent physical model of human upper respiratory tract was prepared based on the completely scanned medical images. By means of selecting appropriate air pressure system, combined with two-dimensional PIV system, a complete experimental apparatus was established. Based on the apparatus, preliminary experiment on air velocity in human upper respiratory tract flow field was conducted, and the experiment result was compared with the numerical simulation result. Results Under the steady breathing pattern at respiratory flow of 30 L/min, respiratory air flow measured by the experimental apparatus led to the formation of vortex structure in the front part of oral cavity. Air velocity was relatively higher both in the lower part of oral cavity near the upper tongue and in the middle part of oral cavity, while the velocity was relatively lower in the other parts of oral cavity. The results were in accordance with numerical simulation. Conclusions The experimental apparatus for human upper respiratory tract flow measurement based on PIV technology is practical and reliable, which can be applied in the measurement of airflow organization patterns and vorticity distributions in human upper respiratory tract, and realize the verification of numerical simulation results.