scholarly journals Design, Control, Modeling, and Simulation of Mechanical Ventilator for Respiratory Support

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Anh Son Tran ◽  
Ha Quang Thinh Ngo ◽  
Van Keo Dong ◽  
Anh Huy Vo
Keyword(s):  
Open Source ◽  
Flow Rate ◽  
Mechanical Design ◽  
Early Stage ◽  
Lung Model ◽  
Mechanical Ventilator ◽  
Test Scenario ◽  
Tracking Errors ◽  
Robust Solution ◽  
Control Rules

In the early stage of the 21st century, humankind is facing high medical risks. To the best of our knowledge, there is currently no efficient way to stop chains of infections, and hence citizens suffer significantly increasing numbers of diseases. The most important factor in this scenario is the lack of necessary equipment to cure disease and maintain our living. Once breath cannot be guaranteed, humans find themselves in a dangerous state. This study aimed to design, control, model, and simulate mechanical ventilator that is open-source structure, lightweight, and portable, which is proper for patients to cure themselves at home. In the scope of this research, the hardware platform for the mechanical design, implementation of control rules, and some trials of both simulations and experiments are presented as our methodology. The proposed design of ventilator newly features the bioinspired mechanism, finger-like actuator, and flow rate-based control. Firstly, the approximate evaluation of the lung model is presented with some physiological characteristics. Owing to this investigation, the control scheme was established to adapt to the biological body. Moreover, it is essential for the model to be integrated to determine the appropriate performance of the closed-loop system. Derived from these theoretical computations, the innovative concept of mechanical design was demonstrated using the open-source approach, and the real-world model was constructed. In order to estimate the driving torque, the hardware modeling was conducted using mathematical expressions. To validate the proposed approach, the overall system was evaluated using Matlab/Simulink, and experiments with the proposed platform were conducted in two situations: 20 lpm as a reference flow rate for 4 seconds and 45 lpm for 2.5 seconds, corresponding to normal breath and urgent breath. From the results of this study, it can be clearly observed that the system’s performance ensures that accurate airflow is provided, although the desired airflow fluctuates. Based on the test scenario in hardware, the RMS (root-mean-square) values of tracking errors in airflow for both cases were 1.542 and 1.767. The proposed design could deal with changes in airflow, and this machine could play a role as a proper, feasible, and robust solution to support human living.

scholarly journals An Adaptive Neuro-Fuzzy Control of Pneumatic Mechanical Ventilator

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 51
Author(s):  
Jozef Živčák ◽  
Michal Kelemen ◽  
Ivan Virgala ◽  
Peter Marcinko ◽  
Peter Tuleja ◽  
...  
Keyword(s):  
Control System ◽  
Control Algorithm ◽  
Fuzzy Inference ◽  
Fuzzy Controller ◽  
Mechanical Design ◽  
Mechanical Ventilator ◽  
Mechanical Ventilators ◽  
Inference System ◽  
Control Approach ◽  
Neuro Fuzzy

COVID-19 was first identified in December 2019 in Wuhan, China. It mainly affects the respiratory system and can lead to the death of the patient. The motivation for this study was the current pandemic situation and general deficiency of emergency mechanical ventilators. The paper presents the development of a mechanical ventilator and its control algorithm. The main feature of the developed mechanical ventilator is AmbuBag compressed by a pneumatic actuator. The control algorithm is based on an adaptive neuro-fuzzy inference system (ANFIS), which integrates both neural networks and fuzzy logic principles. Mechanical design and hardware design are presented in the paper. Subsequently, there is a description of the process of data collecting and training of the fuzzy controller. The paper also presents a simulation model for verification of the designed control approach. The experimental results provide the verification of the designed control system. The novelty of the paper is, on the one hand, an implementation of the ANFIS controller for AmbuBag pressure control, with a description of training process. On other hand, the paper presents a novel design of a mechanical ventilator, with a detailed description of the hardware and control system. The last contribution of the paper lies in the mathematical and experimental description of AmbuBag for ventilation purposes.

scholarly journals Description of Fracture Network of Hydraulic Fracturing Vertical Wells in Unconventional Reservoirs

2021 ◽  
Vol 9 ◽  
Author(s):  
Jinghua Liu ◽  
Mingjing Lu ◽  
Guanglong Sheng
Keyword(s):  
Flow Rate ◽  
Early Stage ◽  
Fractal Theory ◽  
Fracture Network ◽  
Unconventional Reservoirs ◽  
Box Dimension ◽  
Vertical Wells ◽  
Reservoir Permeability ◽  
Fractal Index ◽  
Volume Fracturing

Based on the distribution of complex fractures after volume fracturing in unconventional reservoirs, the fractal theory is used to describe the distribution of volume fracture network in unconventional reservoirs. The method for calculating the fractal parameters of the fracture network is given. The box dimension method is used to analyze a fracturing core, and the fractal dimension is calculated. The fractal index of fracture network in fracturing vertical wells are also firstly calculated by introducing an analysis method. On this basis, the conventional dual-media model and the fractal dual-media model are compared, and the distribution of reservoir permeability and porosity are analyzed. The results show that the fractal porosity/permeability can be used to describe the reservoir physical properties more accurately. At the same time, the flow rate calculating by conventional dual-media model and the fractal dual-media model were calculated and compared. The comparative analysis found that the flow rate calculated by the conventional dual-media model was relatively high in the early stage, but the flow rate was not much different in the later stage. The research results provide certain guiding significance for the description of fracture network of volume fracturing vertical well in unconventional reservoirs.

scholarly journals Linear controller proposal applied to the virtual servomechanism from an open source mechanical ventilator system

2020 ◽  
Author(s):  
Angel de Salem Martinez-Casaos ◽  
Diego Colin Lancon-Banos ◽  
Jorge Antonio Hernandez-Mendoza ◽  
Jorge Santana-Ramirez ◽  
Maria Magdalena Espinosa-Vazquez ◽  
...  
Keyword(s):  
Open Source ◽  
Mechanical Ventilator ◽  
Linear Controller

scholarly journals Bio-Inspired Robotic Solutions for Landslide Monitoring

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1256 ◽  
Author(s):  
Luca Patané
Keyword(s):  
Mechanical Design ◽  
Early Stage ◽  
Smart Sensors ◽  
Landslide Monitoring ◽  
Dynamic Simulations ◽  
Area Of Interest ◽  
Landslide Event ◽  
The Status ◽  
Design Systems ◽  
Target Locations

Bio-inspired solutions are often taken into account to solve problems that nature took millions of years to deal with. In the field of robotics, when we need to design systems able to perform in unstructured environments, bio-inspiration can be a useful instrument both for mechanical design and for the control architecture. In the proposed work the problem of landslide monitoring is addressed proposing a bio-inspired robotic structure developed to deploy a series of smart sensors on target locations with the aim of creating a sensor network capable of acquiring information on the status of the area of interest. The acquired data can be used both to create models and to generate alert signals when a landslide event is identified in the early stage. The design process of the robotic system, including dynamic simulations and robot experiments, will be presented here.

Development of a Novel High Pressure Electronic Pneumatic Pressure Reducing Valve

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Xu Zhipeng ◽  
Wang Xuanyin
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Closed Loop ◽  
Mechanical Design ◽  
Mathematic Model ◽  
Load Flow ◽  
Pneumatic Pressure ◽  
Output Pressure ◽  
Novel Structure ◽  
Pressure Reducing Valve

Pressure reducing valve (PRV) is one of the critical components in high pressure pneumatic systems. Nowadays, manually operated PRVs have been widely used, but there is still no universal electronic PRV. Thus, we proposed a novel high pressure electronic pneumatic pressure reducing valve (EPPRV) whose inlet pressure (pi) is up to 31.5 MPa. The EPPRV mainly consists of a poppet structured pilot valve and a piston structured main valve. A proportional electromagnet was used as the command element, and a pressure closed loop, rather than a force closed loop controller, was designed. First, the mechanical design and functionality of the EPPRV are carefully analyzed. Then, a mathematical model is built up, and the working characteristics of pressure, flow rate, and frequency response are simulated. Finally, the test bench is introduced, and detailed experiments are carried out. Simulated and experimental results are highly consistent within output pressure (po) ranging from 8 MPa to 25 MPa and load flow rate (qld) ranging from 60 g/s to 650 g/s, which verifies the feasibility of the novel structure and the validity of the mathematic model.

Sensitivity of Digital Thermal Monitoring Parameters to Reactive Hyperemia

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Mohammad W. Akhtar ◽  
Stanley J. Kleis ◽  
Ralph W. Metcalfe ◽  
Morteza Naghavi
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Vascular Reactivity ◽  
Early Stage ◽  
Reactive Hyperemia ◽  
Assessment Tools ◽  
Functional Evaluation ◽  
Thermal Monitoring ◽  
Essential Components ◽  
Baseline Flow

Both structural and functional evaluations of the endothelium exist in order to diagnose cardiovascular disease (CVD) in its asymptomatic stages. Vascular reactivity, a functional evaluation of the endothelium in response to factors such as occlusion, cold, and stress, in addition to plasma markers, is the most widely accepted test and has been found to be a better predictor of the health of the endothelium than structural assessment tools such as coronary calcium scores or carotid intima-media thickness. Among the vascular reactivity assessment techniques available, digital thermal monitoring (DTM) is a noninvasive technique that measures the recovery of fingertip temperature after 2–5 min of brachial occlusion. On release of occlusion, the finger temperature responds to the amount of blood flow rate overshoot referred to as reactive hyperemia (RH), which has been shown to correlate with vascular health. Recent clinical trials have confirmed the potential importance of DTM as an early stage predictor of CVD. Numerical simulations of a finger were carried out to establish the relationship between DTM and RH. The model finger consisted of essential components including bone, tissue, major blood vessels (macrovasculature), skin, and microvasculature. The macrovasculature was represented by a pair of arteries and veins, while the microvasculature was represented by a porous medium. The time-dependent Navier–Stokes and energy equations were numerically solved to describe the temperature distribution in and around the finger. The blood flow waveform postocclusion, an input to the numerical model, was modeled as an instantaneous overshoot in flow rate (RH) followed by an exponential decay back to baseline flow rate. Simulation results were similar to clinically measured fingertip temperature profiles in terms of basic shape, temperature variations, and time delays at time scales associated with both heat conduction and blood perfusion. The DTM parameters currently in clinical use were evaluated and their sensitivity to RH was established. Among the parameters presented, temperature rebound (TR) was shown to have the best correlation with the level of RH with good sensitivity for the range of flow rates studied. It was shown that both TR and the equilibrium start temperature (representing the baseline flow rate) are necessary to identify the amount of RH and, thus, to establish criteria for predicting the state of specific patient’s cardiovascular health.

“Where do I find that?”: creating a central shared documentation system for publishing staff using Google tools at the University of Michigan Library

2014 ◽  
Vol 31 (10) ◽  
pp. 6-9
Author(s):  
Alix Norton
Keyword(s):  
Open Source ◽  
Central Area ◽  
University Of Michigan ◽  
Documentation System ◽  
Content Type ◽  
Robust Solution ◽  
Internal Resources ◽  
Library System ◽  
The Many ◽  
The University

Purpose – This aim of this report is to summarize how Google Sites can be used as an open-source, intuitive, and robust solution for designing an intranet system for a unique library department. Michigan Publishing is a department within the University of Michigan (U-M) campus library system that also includes a revenue-based operation as the U-M Press. The need for a central documentation system has become apparent to organize and streamline policies and procedures in this unique library department. Google Sites was chosen as a solution to compile departmental documentation and serve as a collaborative space for the many units within Michigan Publishing. Design/methodology/approach – One librarian and one graduate student intern worked on this project for 5-10 hours a week over the course of three months. Michigan Publishing managers created an inventory showing all existing informational resources in the department, and were then interviewed about these resources. An initial “landing page” was created for this Google-based site, and more comprehensive content has since been migrated from existing informational resources to this central site. Findings – A specific Google Sites Staff Intranet for Michigan Publishing has been an integral solution for providing a one-stop, central area for current internal resources. It also fosters a sense of departmental identity and community, since there are many separate units within the department, each with a different focus and place within the larger library system. This site provides an online forum for collaboration, communication and policy codification. Originality/value – This report summarizes how Google Sites can be used as an open-source, intuitive, and robust solution for designing an intranet system for a unique library department.

Development and Test of Oxide/Oxide CMC Combustor Liner Demonstrators for Aero Engines

2016 ◽  
Author(s):  
Thomas Behrendt ◽  
Stefan Hackemann ◽  
Peter Mechnich ◽  
Yuan Shi ◽  
Sandrine Hönig ◽  
...  
Keyword(s):  
Protective Coating ◽  
Mechanical Design ◽  
Early Stage ◽  
Ceramic Matrix Composites ◽  
Matrix Composites ◽  
Failure Model ◽  
Design Development ◽  
Post Test ◽  
Aero Engines ◽  
Combustor Liner

Ceramic matrix composites (CMC) offer the potential of increased service temperatures and are thus an interesting alternative to conventional combustor alloys. Tubular combustor liner demonstrators made of an oxide/oxide CMC were developed for a lean combustor in a future aero-engine in the medium thrust range and tested at engine conditions. During the design various aspects like protective coating, thermo-mechanical design, development of a failure model for the CMC as well as design and test of an attachment system were taken into account. The tests of the two liners were conducted at conditions up to 80% take-off. A new protective coating was tested successfully with a coating thickness of up to t=1 mm. Different inspection criteria were derived in order to detect crack initiation at an early stage for a validation of the failure model. With the help of detailed pre- and post-test computer tomography scans to account for the micro structure of the CMC the findings of the failure model were in reasonable agreement with the test results.

scholarly journals Comparative Study on Computer Simulation of Solar Shading Performance with Heliodon and Artificial Sky

2021 ◽  
Vol 8 (1) ◽  
pp. 50-64
Author(s):  
David B. Dalumo ◽  
◽  
Yaik-Wah Lim ◽  
◽  
Keyword(s):  
Mechanical Design ◽  
Early Stage ◽  
Computational Simulation ◽  
Physical Experiment ◽  
Scale Model ◽  
Technological Advancement ◽  
Efficient Design ◽  
Evaluation Approach ◽  
Solar Shading ◽  
Simulation Results

Current technological advancement and the requirement for sustainability-driven practices has birthed increased demands for accuracy in performance and assessment of energy consumption in the built environment. Energy-efficient and sustainable building projects are to large extents dependent on achieving functional solar shading and sufficient daylighting in building interiors. Hence, the understanding and adequate evaluation of the sun and its dynamic influence on buildings right at the early stage of planning and design is essential for the development of performance-driven building designs. In this study, the performance simulation results of Integrated Environmental Solutions <Virtual Environment> software program modules are examined for accuracy in executing performance analysis of solar shading. This study assesses the shading prediction of Suncast; a virtual solar shading calculation tool, and RadianceIES for measuring daylight availability in a tropical climate region. The evaluation of shading performance with Suncast was validated through physical experiment by comparing the results obtained therein with shading analysis outcomes generated on a scale model with the aid of a heliodon. Likewise, RadianceIES daylighting simulations were compared with measurements realised from an artificial sky simulator. The results were further subjected to correlation tests to determine the relationship between simulation and physical experiment results. The computational evaluation approach presented more efficient means of conducting the performance simulations over the physical experiment methods which were limited by mechanical design of the components. Suncast and RadianceIES simulation results presented comparable equivalence with measurement output acquired from the heliodon and artificial sky respectively, with minimal variations in accuracy. Thus, demonstrating the ability of the computational simulation program in accurately predicting solar shading and daylight performance in buildings, this could benefit architects in the proper and efficient design of shading devices for building facades at early design stages.

scholarly journals Basic Principles of Antibiotics Dosing in Patients with Sepsis and Acute Kidney Damage Treated with Continuous Venovenous Hemodiafiltration

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Aleksandra Nikolić ◽  
Sasa Jaćović ◽  
Željko Mijailović ◽  
Dejan Petrović
Keyword(s):  
Intensive Care ◽  
Renal Clearance ◽  
Intensive Care Units ◽  
Flow Rate ◽  
Early Stage ◽  
Target Therapy ◽  
Kidney Damage ◽  
Dialysis Dose ◽  
Continuous Venovenous Hemodiafiltration ◽  
The Impact

Abstract Sepsis is the leading cause of acute kidney damage in patients in intensive care units. Pathophysiological mechanisms of the development of acute kidney damage in patients with sepsis may be hemodynamic and non-hemodynamic. Patients with severe sepsis, septic shock and acute kidney damage are treated with continuous venovenous hemodiafiltration. Sepsis, acute kidney damage, and continuous venovenous hemodiafiltration have a significant effect on the pharmacokinetics and pharmacodynamics of antibiotics. The impact dose of antibiotics is increased due to the increased volume of distribution (increased administration of crystalloids, hypoalbuminemia, increased capillary permeability syndrome toproteins). The dose of antibiotic maintenance depends on renal, non-renal and extracorporeal clearance. In the early stage of sepsis, there is an increased renal clearance of antibiotics, caused by glomerular hyperfiltration, while in the late stage of sepsis, as the consequence of the development of acute renal damage, renal clearance of antibiotics is reduced. The extracorporeal clearance of antibiotics depends on the hydrosolubility and pharmacokinetic characteristics of the antibiotic, but also on the type of continuous dialysis modality, dialysis dose, membrane type, blood flow rate, dialysis flow rate, net filtration rate, and effluent flow rate. Early detection of sepsis and acute kidney damage, early target therapy, early administration of antibiotics at an appropriate dose, and early extracorporeal therapy for kidney replacement and removal of the inflammatory mediators can improve the outcome of patients with sepsis in intensive care units.

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