Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
DESIGN AND MANUFACTURE OF THE SYSTEM MEASUREMENT OF THE AIR FLOW IN THE ALTERNATIVE PULMONARY MECHANICAL VENTILATOR
Submission Author:
Felipe Pamplona Mariano , GO , Brazil
Co-Authors:
Felipe Pamplona Mariano, Andreia Aoyagui Nascimento, Anderson Girardi, João Paulo Fonseca, Sigeo Kitatani Júnior
Presenter: Felipe Pamplona Mariano
doi://10.26678/ABCM.COBEM2021.COB2021-1670
Abstract
The COVID-19 pandemic, caused by Sars-CoV-2, induces a Severe Acute Respiratory Syndrome (SARS), which can be treated, in part, with the use of Pulmonary Mechanical Ventilator (PMV). The increase in the number of cases induced a lack of PMV in Intensive Care Units. The problem was amplified because there was no availability to import these devices, by generating a global crisis. Therefore, an alternative PMV project was proposed, their key characteristics are the manufacture with materials and instrumentation equipment found in Brazil. The present paper shows the design and manufacture of the system measurement of the air flow in the alternative PMV. For the correct control of the air flow sent to the lungs, the presence of a flowmeter is mandatory, the most conventional used types in PMV are linear resistance pneumotachographs, variable orifice meters, hot wire anemometers and ultrasonic. However, all cited flowmeters have limitations for national manufacturing due to the special materials and high value for their acquisition. The flowmeter proposed for the alternative PMV is of the type orifice plate concentric quadrant edge, which has the advantage of keeping the discharge coefficient constant, even if the flow is laminar. The project of the flowmeter is presented to optimize the pressure difference in the flow, since, on the one hand, the pressure difference has a maximum limit imposed and, moreover, the pressure gauge needs a minimum level of pressure difference to record values with minor errors. Details of the orifice plate fabrication are also presented, highlighting the manufacture of the rounded edge. Lastly, the results of the process of obtaining the discharge coefficients are presented as a function of the Reynolds number to the three orifice plates, the concentric quadrant edge compared with the square edge and square edge recessed. After the installation of the new orifice plate, the alternative PMV worked properly, obtaining satisfactory results when compared with a gold standard PMV in animal clinical tests.
Keywords
biomedical equipment, medical control systems, flowmeter, orifice plate
