Calibration of Unicapillary Pneumotachograph Through Computational Fluid Dynamics (CFD) Approach

A pneumotachograph is a device applied to measure gas flow of the respiratory system and can be utilized in mechanical ventilators, spirometry equipments and in scientific researches on the respiratory system. These devices need to be properly characterized to provide reliable measurements. In general, pneumotachographs are characterized experimentally by the calibrated syringe strokes method. Computational Fluid Dynamics (CFD) has been used in different areas of science for the analysis of fluids both in laminar and turbulent regimes quickly and inexpensively. In this work the feasibility of using CFD to obtain calibration curves of a pneumotachograph was verified using the calibrated syringe strokes technique. In this first study it was possible to calculate calibration curves of a pneumotachograph by the novel proposed computational methodology with results similar to the obtained experimentally. The proposed method could be used as preliminary tool to predict the behaviour of each variable involved in this process. Finally, the calculation of volumetric error and standard deviation was realized to compare with experimental results by Minimal Mean Square method.