St. Louis, Missouri
June 18, 2000
June 18, 2000
June 21, 2000
2153-5965
7
5.334.1 - 5.334.7
10.18260/1-2--8432
https://peer.asee.org/8432
443
Session 2509
Hydraulic Lung Analogue
Narciso F. Macia, Amy Gowder Arizona State University
Abstract This paper describes an easy-to-build, hydraulic analogue of the lungs, which has similar mechanical characteristics as an infant lung. It consist of two, clear, U-tubes filled with water (similar to two water-manometers) and connected through two capillary bundles into a T. Since the analogue is passive (it represents an unconscious subject) , it is connected to a ventilator to demonstrate its characteristics. As the air enters through the T, it splits into two pathways (representing the first bifurcation present the trachea), and then passes through two capillary bundles, simulating airway resistance. The other sides of the capillary bundles are connected to the U-tubes, filled with water halfway. Since it is the tendency of the U-tube manometer is to maintain the two water columns at the same level, it provides a recoil effect that simulates lung compliance. The airway resistance can be changed by changing the size and/or number of the small tubes that make the capillary bundle. Lung compliance can be changed by selecting the size of the U-tube, or by placing a solid insert into one or both of U-tubes. This device provides an adequate model for an infant lung provided that the frequency of excitation is not too high. This lung analog is an excellent vehicle for demonstrating the air movement in the respiratory system, since by using clear PVC piping, the water level change is equivalent to the tidal volume. The respiratory system provides excellent example of a dynamic bio-system and a vehicle to model dynamic systems. Introduction The respiratory system is an excellent vehicle for conveying the characteristics of a dynamic system. It provides enough complexity and analogous relationships to make the effort challenging, and also allows the student to work on a system that they are familiar with since they carry it everywhere they go. This exercise offers students the capacity to learn modeling techniques, testing methods, and critical understanding of the respiratory systems. There are several approaches for modeling the respiratory system. These range from simply a tube connected to a balloon, to a system involving bellows1. There is also a commercially available device that allows the selection of compliance and resistance in each of its lobes2. This paper presents another realization of the respiratory system, by utilizing two U-tube manometer tubes, to produce the recoil behavior present in the alveoli and the abdomen/chest wall. It consist of two, clear, U-tubes filled with water (similar to two water-manometers) and
Gowder, A., & Macia, N. F. (2000, June), Hydraulic Lung Analogue Paper presented at 2000 Annual Conference, St. Louis, Missouri. 10.18260/1-2--8432
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