scholarly journals Modelling and Simulation of Volume Controlled Mechanical Ventilation System

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yan Shi ◽  
Shuai Ren ◽  
Maolin Cai ◽  
Weiqing Xu
Keyword(s):  
Mathematical Model ◽  
Mechanical Ventilation ◽  
Respiratory System ◽  
Ventilation System ◽  
Delay System ◽  
Time Delay System ◽  
Typical Time ◽  
Controlled Mechanical Ventilation ◽  
The Mathematical Model ◽  
Volume Controlled

Volume controlled mechanical ventilation system is a typical time-delay system, which is applied to ventilate patients who cannot breathe adequately on their own. To illustrate the influences of key parameters of the ventilator on the dynamics of the ventilated respiratory system, this paper firstly derived a new mathematical model of the ventilation system; secondly, simulation and experimental results are compared to verify the mathematical model; lastly, the influences of key parameters of ventilator on the dynamics of the ventilated respiratory system are carried out. This study can be helpful in the VCV ventilation treatment and respiratory diagnostics.

scholarly journals Decoupling Adaptive Smith Prediction Model of Flatness Closed-Loop Control and Its Application

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 895
Author(s):  
Mingming Song ◽  
Hongmin Liu ◽  
Yanghuan Xu ◽  
Dongcheng Wang ◽  
Yangyang Huang
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Time Delay ◽  
Control Method ◽  
Delay System ◽  
Control Performance ◽  
Time Delay System ◽  
Single Loop ◽  
Flatness Control ◽  
Pure Time Delay

Flatness control system is characterized by multi-parameters, strong coupling, pure time delay, which complicate the establishment of an accurate mathematical model. Therefore, a control scheme that combines dynamic decoupling, PI (Proportion and Integral) control and adaptive Smith predictive compensation is proposed. To this end, a dynamic matrix is used to decouple the control system. A multivariable coupled pure time-delay system is transformed into several independent generalized single-loop pure time-delay systems. Then, a PI-adaptive Smith predictive controller is constructed for the decoupled generalized single-loop pure time-delay system. Simulations show that the scheme has a simple and feasible structure, and good control performance. When the mathematical model of the control system is inaccurate, the control performance of adaptive Smith control method is evidently better than that of the ordinary Smith control method. The model is successfully applied to the cold rolling production site through LabVIEW, and the control accuracy is within 5I. This study reveals a new solution to the problem of coupled pure time-delay in flatness control system.

Research on Identification Model of Stator Core Temperature Rise of a Generator

2014 ◽  
Vol 1070-1072 ◽  
pp. 1216-1221
Author(s):  
Dong Xiang ◽  
Hao Xiong ◽  
Ning Bo Liu ◽  
Qiang Wu ◽  
Guang Wei Meng
Keyword(s):  
Mathematical Model ◽  
Temperature Rise ◽  
Reactive Power ◽  
Ventilation System ◽  
Stator Winding ◽  
Phase Voltage ◽  
Stator Core ◽  
Voltage Phase ◽  
The Mathematical Model ◽  
Generator Stator

This paper takes the ship air-cooled AC generator with the radial ventilation system for example, establishes the mathematical model of a generator core and winding temperature by using an equivalent thermal circuit method and the temperature calculation method based on the operating parameters, analyzes the transfer function between the generator stator winding temperature rise and the phase voltage, phase current and reactive power, and finally verifies validity of the mathematical model by the experiment.

scholarly journals Design and Analysis of a Mechanical Ventilation System Based on Cams

2020 ◽  
Author(s):  
Jesús Calderón ◽  
Carlos Rincón ◽  
Bray Agreda ◽  
Juan José Jiménez
Keyword(s):  
Mathematical Model ◽  
Mechanical Ventilation ◽  
Low Cost ◽  
Ventilation System ◽  
External Solution ◽  
Rotation Frequency ◽  
Medical Centers ◽  
Compression Mechanism ◽  
Available Technology ◽  
Over Time

A mechanical ventilation system is a big support for breathing complications, in which an external solution is quite necessary to keep oxygen compensation in the patients. Its knowledge is well widespread and different equipment has been developed. However, they are very expensive and their quantity in medical centers is not sufficient, especially in Peru. Hence, it has been required to develop new methods to provide oxygen by a low cost equipment; Protofy, a research group from Spain, designed one of the first low cost mechanical ventilation systems which was medically validated by its government. In this sense, a redesign of the mechanical ventilation system was carried out according to the local requirements and available technology, a different airbag resuscitator with different properties and geometry, but maintaining its working concept based on a cam compression mechanism. Sensors and a display were added to improve the performance with a control algorithm for the rotation frequency and to show the ventilation curves over time to the medical staff. It was necessary to develop a mathematical model to relate the behavior between ventilation curves for a patient and physical variables of the design, especially in the epidemic COVID 19, that many countries are dealing with at the time research is being conducted. The mechanical ventilation system was redesigned, fabricated, and tested measuring its ventilation curves over time. Results indicate that this redesign provides a sturdy equipment able to work during a longer lifetime than the original. The replicability of the ventilation curves behavior is assured, while the mechanism dimensions are adapted for a particular airbag resuscitator. The mathematical model of the whole system can predict satisfactorily the ventilation curves over time and was used to provide the air pressure, volume, and flow as a function of the rotation angle measured by sensors.

scholarly journals Dynamic Characteristics of Mechanical Ventilation System of Double Lungs with Bi-Level Positive Airway Pressure Model

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Dongkai Shen ◽  
Qian Zhang ◽  
Yan Shi
Keyword(s):  
Mathematical Model ◽  
Mechanical Ventilation ◽  
Dynamic Characteristics ◽  
Airway Pressure ◽  
Life Support ◽  
Positive Airway Pressure ◽  
Coupling Effect ◽  
Ventilation System ◽  
System A ◽  
Set Up

In recent studies on the dynamic characteristics of ventilation system, it was considered that human had only one lung, and the coupling effect of double lungs on the air flow can not be illustrated, which has been in regard to be vital to life support of patients. In this article, to illustrate coupling effect of double lungs on flow dynamics of mechanical ventilation system, a mathematical model of a mechanical ventilation system, which consists of double lungs and a bi-level positive airway pressure (BIPAP) controlled ventilator, was proposed. To verify the mathematical model, a prototype of BIPAP system with a double-lung simulators and a BIPAP ventilator was set up for experimental study. Lastly, the study on the influences of key parameters of BIPAP system on dynamic characteristics was carried out. The study can be referred to in the development of research on BIPAP ventilation treatment and real respiratory diagnostics.

scholarly journals Static compliance and driving pressure are associated with ICU mortality in intubated COVID-19 ARDS

Critical Care ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Annalisa Boscolo ◽  
Nicolò Sella ◽  
Giulia Lorenzoni ◽  
Tommaso Pettenuzzo ◽  
Laura Pasin ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory System ◽  
Multivariable Analysis ◽  
Ideal Body Weight ◽  
Driving Pressure ◽  
Static Compliance ◽  
Icu Mortality ◽  
Multicenter Cohort Study ◽  
Risk Of Death ◽  
Controlled Mechanical Ventilation

Abstract Background Pathophysiological features of coronavirus disease 2019-associated acute respiratory distress syndrome (COVID-19 ARDS) were indicated to be somewhat different from those described in nonCOVID-19 ARDS, because of relatively preserved compliance of the respiratory system despite marked hypoxemia. We aim ascertaining whether respiratory system static compliance (Crs), driving pressure (DP), and tidal volume normalized for ideal body weight (VT/kg IBW) at the 1st day of controlled mechanical ventilation are associated with intensive care unit (ICU) mortality in COVID-19 ARDS. Methods Observational multicenter cohort study. All consecutive COVID-19 adult patients admitted to 25 ICUs belonging to the COVID-19 VENETO ICU network (February 28th–April 28th, 2020), who received controlled mechanical ventilation, were screened. Only patients fulfilling ARDS criteria and with complete records of Crs, DP and VT/kg IBW within the 1st day of controlled mechanical ventilation were included. Crs, DP and VT/kg IBW were collected in sedated, paralyzed and supine patients. Results A total of 704 COVID-19 patients were screened and 241 enrolled. Seventy-one patients (29%) died in ICU. The logistic regression analysis showed that: (1) Crs was not linearly associated with ICU mortality (p value for nonlinearity = 0.01), with a greater risk of death for values < 48 ml/cmH2O; (2) the association between DP and ICU mortality was linear (p value for nonlinearity = 0.68), and increasing DP from 10 to 14 cmH2O caused significant higher odds of in-ICU death (OR 1.45, 95% CI 1.06–1.99); (3) VT/kg IBW was not associated with a significant increase of the risk of death (OR 0.92, 95% CI 0.55–1.52). Multivariable analysis confirmed these findings. Conclusions Crs < 48 ml/cmH2O was associated with ICU mortality, while DP was linearly associated with mortality. DP should be kept as low as possible, even in the case of relatively preserved Crs, irrespective of VT/kg IBW, to reduce the risk of death.

DIMENSIONLESS OPTIMIZATION STUDY ON A VENTILATOR WITH SECRETION CLEARANCE FUNCTION

2015 ◽  
Vol 15 (03) ◽  
pp. 1550032 ◽  
Author(s):  
YAN SHI ◽  
JINGLONG NIU ◽  
MAOLIN CAI ◽  
WEIQING XU
Keyword(s):  
Mathematical Model ◽  
Simulation Study ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Ventilation System ◽  
Suction Pressure ◽  
Optimization Study ◽  
Expiratory Positive Airway Pressure ◽  
The Mathematical Model ◽  
Secretion Clearance

To improve the efficiency and safety of secretion clearance, a novel ventilator (SC ventilator) with an automatic secretion clearance function is proposed. To lay a foundation for the optimization of the SC ventilator, the basic mathematical model of the ventilation system is derived. By selecting the appropriate reference values, the basic mathematical model is transformed to a dimensionless expression for simulation. Through the experimental and simulation study on the SC ventilation system, it can be concluded that: firstly, the mathematical model is proved to be authentic and reliable. Secondly, the influences of the three key parameters on the dynamics of the SC ventilation system are carried out. Last, to guarantee the pressure in the lung is higher than the expiratory positive airway pressure, the dimensionless minimum pressure in the flexible tube should be set higher than 0.9164, the dimensionless suction pressure should be set higher than 0.79.

Lung-Diaphragm Behavior of the Respiratory System During Input From Excitation

2002 ◽  
Author(s):  
P. Ruby Mawasha ◽  
Paul Lam ◽  
Lalitha Kasturi
Keyword(s):  
Mathematical Model ◽  
Respiratory System ◽  
Periodic Motion ◽  
Constitutive Relations ◽  
Air Flow ◽  
Flow Conditions ◽  
Mouth Pressure ◽  
Parametric Studies ◽  
The Mathematical Model ◽  
Operating Regimes

A numerical behavior of a lung-diaphragm model of a respiratory system during input from mouth pressure and diaphragm excitation is being investigated. A lung-diaphragm is subject to constant inlet air-flow conditions into the respiratory system. The mouth pressure (Macia et. al., 1997) and diaphragm excitation (Ricci et. al., 2002) are described by a constitutive relations containing nonlinearities from rib cage muscles forces and inlet air-flow conditions. Within certain operating regimes, the model exhibits self-excited pulsatile periodic motion and the qualitative features of the response can be understood in terms of the underlying model. Further, the mathematical model is a more general approach and can be used to conduct parametric studies and determine the instability mechanisms involved in the modeling of lung-diaphragm behavior of the respiratory system during input from excitation.

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