Abstract: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.