Biomedical Systems : Modeling and Simulation of Lung Mechanics and Ventilator Controls Design (original) (raw)

Pressure-Volume Controlled Mechanical Ventilator: Modeling and Simulation

2015

In this publication, the pressure and volume controlled type ventilator, providing breathing artificially, has been modeled. Based on the types of ventilators used in clinical medicine, airflow (q) and volume (v) signals vary. This publication has produced the transfer function of the ventilator by taking the ratio of the Laplace transform of paw(t) and q(t) signals, creating [Q (s) / Paw (s)] as a result. Then having obtained the mathematical models of known and used airflow and volume signals in clinical medicine, LabVIEW and MATLAB / Simulink environment based simulations were carried out using the signals present. Pressure-controlled ventilator has been fully modeled with satisfactory simulations results obtained. Volume controlled ventilator has also been modeled, using approximate theoretical mathematical model, and the model has produced satisfactory results as well except a limited and acceptable approximations error. Then the two types of ventilators have been defined in th...

Computer Control of Mechanical Ventilation

Respiratory Care, 2004

Computer control of mechanical ventilators includes the operator-ventilator interface and the ventilator-patient interface. New ventilation modes represent the evolution of engineering control schemes. The various ventilation control strategies behind the modes have an underlying organization, and understanding that organization improves the clinician's appreciation of the capabilities of various ventilation modes and gives an idea of what we can and should expect for the future. The operator-ventilator interface has received little attention in the literature, despite the fact that there is a whole science of human-computer interaction. This report suggests a methodology for the study of ventilator interfaces.

A Mathematical Model of Lung Functionality using Pressure Signal for Volume-Controlled Ventilation

2020 IEEE International Conference on Automatic Control and Intelligent Systems (I2CACIS), 2020

Mechanical Ventilation is used to support the respiratory system malfunction by assisting recovery breathing process which could result from diseases and viruses such as pneumonia and COVID-19. Mathematical models are used to study and simulate the respiratory system supported by mechanical ventilation using different modes such as volumecontrolled ventilation (VCV). In this research, a single compartment lung model ventilated by VCV is developed during real time mechanical ventilation using pressure signal. This mathematical model describes the lung volume and compliance correctly considering positive end expiration pressure (PEEP) value. The model is implemented using LabVIEW tools and can be used to monitor the volume, flow and compliance as outputs of the model. Two experiments are carried out on the proposed lung model at three input scenarios of volume (400, 500 and 600 ml) for each experiment considering a PEEP value. To validate the model, an artificial lung connected to a VCV with the same scenarios is used. Validation check is conducted by comparing the outputs of the lung model to that of the artificial lung. The experimental results showed that the measured lung model outputs with negative feedback are the same for pressure and flow as the outputs without negative feedback, whereas the measured volume is comparatively lower for negative feedback. Average percent error in the experiment with negative feedback (5.14%) is smaller compared to the experiment without negative feedback (9.28%). Furthermore, the average error of the calculated compliance decreases from 16% (without negative feedback) to 2% (with negative feedback). The obtained results of the proposed method showed good performance and acceptable accuracy. Thus, the model facilitates the clinicians and practitioners as a training tool to learn real-time mechanical ventilation functionalities.

A Pulmonary Model for the Automatic Control of a Ventilator

IFAC Proceedings Volumes, 1975

It is the purpose of this paper to present a predicting model of the hole pulmonary function, strictly restricted to physically~essible variables. It has been obtained through a synthesis of existing models with, when necessary, an extension of their domain of validity in order to take into account the three modes of breathing under consideration: artificial, aided, natural. An important experimental environment has been especially developed to check the model, and soon to permit a global pulmonary monitoring of a patient under ventilator. On this basis, we propose a way of an automatic control of ventilator. The above study has been supported by the Physiopathology Department of the Medical Informatic Center and the Automatic Control Department of the University of Brussels. An important movable apparatus for the pulmonary investigation, adapted to the Intensive Care Units, contains the measuring instruments and a screen with a keyboard connected to the computer. It allows an experimental checking of the model, and will serve as a base fur the monitoring of the principal variables acting on or depending from the pulmonary function. The computer can than identify the parameters of the model. simulate A PULMONARY MODEL FOR THE AUTOMATIC CONTROL OF A VENTILATOR

A simulation of a medical ventilator with a realistic lungs model

F1000Research, 2020

Background: The outbreak of COVID-19 pandemic highlighted the necessity for accessible and affordable medical ventilators for healthcare providers. To meet this challenge, researchers and engineers world-wide have embarked on an effort to design simple medical ventilators that can be easily distributed. This study provides a simulation model of a simple one-sensor controlled, medical ventilator system including a realistic lungs model and the synchronization between a patient breathing and the ventilator. This model can assist in the design and optimization of these newly developed systems. Methods: The model simulates the ventilator system suggested and built by the “Manshema” team which employs a positive-pressure controlled system, with air and oxygen inputs from a hospital external gas supply. The model was constructed using SimscapeTM (MathWorks®) and guidelines for building an equivalent model in OpenModelica software are suggested. The model implements an autonomously breathi...

Model‐based control of mechanical ventilation: design and clinical validation

British Journal of Anaesthesia, 2004

Background. We developed a model-based control system using end-tidal carbon dioxide fraction (FE¢ CO 2) to adjust a ventilator during clinical anaesthesia. Methods. We studied 16 ASA I±II patients (mean age 38 (range 20±59) yr; weight 67 (54±87) kg) during i.v. anaesthesia for elective surgery. After periods of normal ventilation the patients were either hyper-or hypoventilated to assess precision and dynamic behaviour of the control system. These data were compared with a previous group where a fuzzy-logic controller had been used. Responses to different clinical events (invalid carbon dioxide measurement, limb tourniquet release, tube cuff leak, exhaustion of carbon dioxide absorbent, simulation of pulmonary embolism) were also noted. Results. The model-based controller correctly maintained the setpoint. No signi®cant difference was found for the static performance between the two controllers. The dynamic response of the model-based controller was more rapid (P<0.05). The mean rise time after a setpoint increase of 1 vol% was 313 (SD 90) s and 142 (17) s for fuzzy-logic and model-based control, respectively, and after a 1 vol% decrease was 355 (127) s and 177 (36) s, respectively. The new model-based controller had a consistent response to clinical artefacts. Conclusion. A model-based FE¢ CO 2 controller can be used in a clinical setting. It reacts appropriately to artefacts, and has a better dynamic response to setpoint changes than a previously described fuzzy-logic controller.