Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
MATHEMATICAL MODELING AND SIMULATION OF AN INTENSIVE CARE UNIT MECHANICAL VENTILATOR FOR HEATING AND AIR HUMIDIFICATION TRANSIENT ANALYSIS
Submission Author:
Francisco Kleber Regis Castro , SP
Co-Authors:
Francisco Kleber Regis Castro, Murilo Gasparin Rampi, Isabela Fernanda Rocha Corrêa, Lauber Martins, Fernando Gallego Dias, JOSÉ VIRIATO COELHO VARGAS, Abdel-Farid Mamadou Idrissou
Presenter: Francisco Kleber Regis Castro
doi://10.26678/ABCM.ENCIT2022.CIT22-0465
Abstract
Mechanical ventilators are machines built to care for patients who are clinically unstable or in a poor general condition, unable to breathe spontaneously. This is the case for patients who are infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The temperature and absolute humidity of the trachea of a healthy person varies between 32 and 34oC and 25 and 35 mgH2O L-1 respectively, with a relative humidity of approximately 95%. The temperature and relative humidity of the air supplied to the patient connected to a ventilator varies between 32 and 34oC and between 95 and 100%, respectively. International recommendations standardize that the air supplied must have 100% relative humidity, absolute humidity between 36 and 40 mgH2O L-1 and temperature between 31 and 35oC. In this sense, a mathematical model of a mechanical ventilator was developed with the aim of providing air with properties recommended by international guidelines, which will bring less discomfort to patients during intubation and a quick recovery, leading to a high faster, making equipment and beds more readily available to others. The model was built by applying the conservation laws (mass and energy) to calculate and control in real time the physical properties at the machine/patient interface (mouth) and keep the air insufflated under the conditions recommended by the protocols. The results will show in real time, the influence of external parameters (temperature and humidity of external air) on parameters such as temperature and humidity of the air provided to the patient. The properties of the air supplied to ICU patients follow restrict guidelines and this model will provide a design tool and control strategy to keep those conditions unaltered even when external parameters change. A simulation code with low computational time capable of capturing the transient and spatial behavior of the system was developed to solve Ordinary Differential Equations (ODEs) generated with time as an independent variable. The model will be a design tool for ventilators, as it controls parameters such as temperature and humidity in real time, avoiding inflicting other medical conditions on patients such as hypothermia, hyperthermia, mucus, bronchial tree injuries, mucosal ulceration, inflammation and ciliostasis.
Keywords
Mechanical ventilator, mathematical model, Properties recommended, Simulation, Controls parameters, Temperature, Humidity
