NUST Institutions Library Catalogue

Breathing is phenomenon essential for every mammal on Earth. Key role of respiratory system is transmission of vital gases between air and blood. Conventionally some macroscale techniques for flow visualization in trachea-bronchial region was achieved by using 3D printing of idealized/realistic airways model. Due to limitations in fabrication and CT image resolution, limited amount of experimental study is done on bronchial region. We fabricated simplified model of terminal bronchi airways by using polydimethylsiloxane. Micro-fluidic channel is fabrication by using the 3D printed molds via SLA printer (FormLabs 3+ with layer thickness of 50 μm). The mold is then used to fabricate transparent channel of PDMS which is good for visualization of flow. It is first of its kind of fabrication of terminal bronchial airways by using microfluidic chip fabrication method. Moreover, the chips fabricated using the PDMS have some paybacks like we can easily visualize flow passing through the airways. We use syringe pumps for flow of three breathing conditions sleep, normal and exercise. We demonstrated airways focusing using microscope and visualized fluid flow by using particle image velocimetry method. The statistics evidence good agreement with our experimental results and simulation results from the literature. The results shows that turbulence kinetics energy decreases by using pressurized meter dose inhaler.