Modeling of thermophysiological state of man

2021 ◽  
pp. 30-38
Author(s):  
Mykola Pyroh ◽  
Iryna Harko ◽  
Ksenia Dukhnovska
Keyword(s):  
Blood Flow ◽  
Information Systems ◽  
Life Support ◽  
Basic Element ◽  
Continuum Models ◽  
Heat Output ◽  
Total Heat Transfer ◽  
Advantages And Disadvantages ◽  
Continuous Models ◽  
Vascular Geometry

This article presents an analysis of mathematical models that can be used to predict the thermophysiological state of man in different environmental conditions in the development of information systems for its life support. The basic element of all considered models is the equation of heat balance. According to this equation, the total heat transfer of the organism must be equal to its heat output. The article considers continuous and discrete-vascular models, analyzes their advantages and disadvantages. Continuous models are, in essence, a simplified notation of biothermal equations. In these models, the effect of blood flow on each individual vessel is neglected, and the blood supply is averaged over the volume studied. Discrete-vascular models are a set of biothermal equations that describe the blood flow in each individual vessel. Discrete-vascular models of the thermophysiological state of man are not very applicable today, due to the complex and insufficiently studied vascular geometry. More common are continuum models, for the construction of which a multi-compartmental approach is used. As a result, the article presents a comparative table of continuous models and information systems that use these models.

scholarly journals Flow manipulation and the association with myocardial contractility during extracorporeal life support (FLAME)

2021 ◽  
Vol 10 (Supplement_1) ◽  
Author(s):  
SKT Ma ◽  
WC Sin ◽  
CW Ngai ◽  
ASK Wong ◽  
WM Chan ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiogenic Shock ◽  
Myocardial Contractility ◽  
Life Support ◽  
Extracorporeal Life Support ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Ventricular Contractility ◽  
Left Ventricular Contractility ◽  
Extracorporeal Blood

Abstract Funding Acknowledgements Type of funding sources: None. Background Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is an advanced technique in extracorporeal life support (ECLS) used to support extreme circulatory failure including patients with cardiac arrest and cardiogenic shock refractory to conventional support. It is a long-standing belief that peripheral V-A ECMO poses increased afterload to the inured heart, but conventional echocardiographic measurements are often insensitive in detecting subtle changes in loading conditions. Purpose This study aimed to evaluate the effects of varying blood flow during peripheral V-A ECMO on intrinsic myocardial contractility, using detailed echocardiographic assessment including speckle tracking echocardiography (STE). Methods Adult patients with acute cardiogenic shock who were supported by peripheral V-A ECMO from April 2019 to September 2020 were recruited. Serial hemodynamic and cardiac performance parameters were measured by transthoracic echocardiogram (TTE) within 48 hours after implementation of V-A ECMO, at different levels of extracorporeal blood flow – 100%, 120% and 50% of target blood flow (TBF). Results A total of 30 patients were included. 22 (71%) were male, and the mean (SD) age was 54 (13) years. The major indications for V-A ECMO were myocardial infarction (19, 63% patients), and myocarditis (5, 17%). With a decrease in extracorporeal blood flow from 100% to 50% of TBF, mean arterial pressure (MAP) dropped from 76+/-3 to 64+/-3mmHg (p <0.001), and cardiac index (CI) increased from 0.89+/-0.13 to 1.27+/-0.18L/min/m2 (p < 0.001). All indices of left ventricular contractility improved at a lower extracorporeal blood flow: the myocardial contractility measured by global longitudinal peak systolic strain (GLPSS) improved from -3+/-0.7% to -5+/-0.8% (p < 0.001); left ventricular ejection fraction (LVEF) increased from 21.5+/-2.6% to 30.9+/-2.7% (p < 0.001) and 19.7+/-3.1% to 28.4+/-3.2% (p < 0.001) by biplane and linear methods, respectively; left ventricular index of myocardial performance (LIMP) improved from 1.51+/-0.12 to 1.03+/-0.09 (p < 0.001). Similar findings were reproduced when comparing left ventricular contractility at extracorporeal blood flows of 120% and 50% of TBF. Conclusions The ECMO blood flow rate in peripheral V-A ECMO is inversely related to myocardial contractility, and is quantifiable by myocardial strain measured by STE.

BLOOD FLOW SIMULATION USING SPH METHOD IN LS-DYNA, ANALYSIS OF ADVANTAGES AND DISADVANTAGES

2021 ◽  
Author(s):  
Marko Topalovic ◽  
◽  
Aleksandar Nikolic ◽  
Miroslav Zivkovic
Keyword(s):  
Blood Flow ◽  
Flow Simulation ◽  
Fem Analysis ◽  
Sph Method ◽  
Shell Elements ◽  
Advantages And Disadvantages ◽  
Fluid Analysis ◽  
Eulerian Formulation ◽  
Mesh Free ◽  
Modelling Methodology

The purpose of this research was to investigate the possibility of blood flow modelling in LS-DYNA using its SPH solver and SPH-FEM coupling. SPH and FEM methods are both based on the continuum mechanics, and SPH uses Lagrangian material framework, while FEM can use both Lagrangian for solid, and Eulerian formulation for fluid analysis. SPH implementation is mesh-free giving it the capability to model very large deformations without mesh distortions. However, this comes at a high computational price, so the number of SPH particles needs to be significantly lower in comparison to the number of FEM elements in the Eulerian analysis of the same fluid domain. In the case of combined SPH-FEM analysis, the blood vessel wall is modelled with FEM shell elements, while the blood inside is modelled with SPH particles. The contact between the two is done using nodes to surface algorithm, while if we use the SPH only, there is no need for the specific contact definition. The Lagrangian framework of the SPH method means that we need to generate particles at one end, and to destroy them on the other, in order to generate a continuous fluid flow. To do this we used activation and deactivation planes, which is a solution implemented in the commercial LS-Dyna SPH solver. In the results section of the paper, the velocity field of blood obtained by implementation of described modelling methodology is shown. SPH-FEM coupling offers greater possibilities to study the effects of wall deformations, tracking of movement of solid particle inclusion, or mixing two different fluids, but it requires elaborate contact definition, and prolonged analysis time in comparison to the FEM CFD analysis.

scholarly journals Approaches and Solutions for Creating Atlases in Geographic Information Systems

2020 ◽  
Vol 19 (33) ◽  
pp. 4-17
Author(s):  
Sergei Krylov ◽  
Gleb Zagrebin ◽  
Dmitriy Mosolov ◽  
Irina Shkurenkova
Keyword(s):  
Information Systems ◽  
Geographic Information Systems ◽  
Geographic Information ◽  
Regional Mapping ◽  
Mathematical Basis ◽  
Summary Table ◽  
Advantages And Disadvantages ◽  
Python Programming Language ◽  
Developer Tools ◽  
Python Programming

The features, advantages and disadvantages of using QGIS, ArcGIS and MapInfo Pro when creating atlases of various types (geographic, complex and thematic) are considered in this paper. Schemes for their potential organization are presented and technological schemes for their automated creation in these geographic information systems are proposed. As a result, approaches and solutions for improving geographic information software can be formulated. Algorithms and modules were developed, primarily aimed at formalizing the structure of atlases and automating the design process of their mathematical basis. The development of functionality was implemented using built-in developer tools implemented in MapInfo as the MapBasic language, and in ArcGIS and QGIS in the Python programming language. A summary table was compiled, which presents the basic functionalities required to create atlases in GIS and their implementation in the appropriate software. These proposals will ensure the fulfillment of all requirements necessary for atlas design, primarily at the regional mapping level.

scholarly journals “Leviathan”, or an essay on the doctrine of the state by T. Hobbes

2020 ◽  
Vol 23 (8) ◽  
pp. 26-36
Author(s):  
Vadym Nikolenko
Keyword(s):  
Human Nature ◽  
Social Order ◽  
Life Support ◽  
The State ◽  
Psychological Traits ◽  
Advantages And Disadvantages ◽  
Political Views ◽  
The Social ◽  
Social Philosopher ◽  
Legitimate State

The study focuses on individual episodes of the biography, the most notable ideas and main socio-political views of the outstanding English scientist, social philosopher, theorist of the origin of the state – T. Hobbes. On the basis of the classic work “Leviathan”, his backbone thoughts on the processes of state building, the development of a balanced normative and legislative system and specific motives for striving for power are highlighted. In particular, attention is focused on the search by the researcher of the optimal balance between freedom and the duties of a citizen. The aspiration of the classic to a comprehensive study of the most effective mechanism, optimal forms of public administration, primarily for the establishment of stable social order and safety, is noted. The scientist emphasized that an authoritative, sovereign, legitimate state is able to effective cope with the tasks set. In which those in power are obliged to be guided by norms of morality and law. Characterized, according to the researcher, the socio-psychological traits of both average citizens and sovereigns for the full life support of the country.Highlighted his heuristic principles of anthropomorphism, which more metaphorically, expressively detail the likely destructive diseases of the state, among which he considered the lack of frugality and the processes of oligarchization of the socio-political system to be especially unsafe. Scientists emphasized the absolute rejection of corruption, lack of social justice, abuse of power. Thus, the advantages and disadvantages of various forms of government were highlighted, in particular, monarchical, aristocratic, democratic. The scientists himself was an active supporter of absolute monarchy and the unshakable authority of the state. At the same time, he focused not so much on the duties of citizens to the state, as on the duties of state representatives to their citizens, the implementation of which can state structure effective, authoritative and legitimate. At the same time, the contribution of T. Hobbes to the development of the philosophy of law is highlighted. In general, it was emphasized that the English scientist comprehensively substantiated his own thought about the immutability of human nature in the form of manifestations of selfishness, individualism, insatiable appetites, unrestrained passions, and the desire for social change. According to the philosopher, only a just, sovereign, authoritative state is capable of curbing the negative manifestations of human nature. In addition, attention focused on the state-forming nature of his philosophy and the scientist’s significant contribution to the development of the theory of the social contract or the contractual origin of the state is highlighted.

scholarly journals Foreign free software for computerized library information systems

2020 ◽  
pp. 69-78
Author(s):  
O. V. Izmestyeva ◽  
D. S. Matusevich
Keyword(s):  
Information Systems ◽  
General Trend ◽  
Information Infrastructure ◽  
Free Software ◽  
Competitive Market ◽  
Advantages And Disadvantages ◽  
Community Trust

Free software enables its free use by anyone under observance of user proprietary rights. The authors review the market of free computerized library information systems. The origins for applying free ALIS are specified; free Evergreen и Koha ALIS are characterized and compared; the list of foreign free ALIS, date and state of development are specified. The methodology for ALIS market estimation is suggested; the role of ALIS developing and related communities is emphasized. The library and designer aspects of ALIS development are described. The new phenomenon of «donation culture» emerged due to implementing free software in libraries. The typical copyright conflict around Koha ALIS between proprietors and independent designers (the latter won with establishing community trust) is described. Using free ALIS follows the general trend of applying free software in public offices, with all advantages and disadvantages of this information infrastructure. As a result, free software is often opposed by the proprietary one, however both components make the competitive market offering users to make choice of ALIS of appropriate price/quality balance. 

Abstract 289: Effect of Elevated Legs on Hemodynamic Performance During Cardiopulmonary Resuscitation in a Porcine Model of Cardiac Arrest

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Eric Qvigstad ◽  
Andres Neset ◽  
Theresa M Olasveengen ◽  
øystein Tømte ◽  
Morten Eriksen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Supine Position ◽  
Life Support ◽  
Advanced Life Support ◽  
Aortic Pressure ◽  
Coronary Perfusion Pressure ◽  
Right Atrial ◽  
Positive Pressure ◽  
Coronary Perfusion ◽  
End Tidal

Purpose of the study: During advanced life support (ALS) end-tidal carbon dioxide (EtCO 2 ) reflects cardiac output (CO). A recent clinical study found an association between passive leg raising (PLR) and increased EtCO 2 during ALS. This may reflect a transient increase in pulmonary blood flow and CO, but might cause a detrimental decrease in coronary perfusion pressure (CPP). We evaluated the effect of PLR during experimental ALS in a randomized, factorial design. Materials and methods: In nine anesthetized domestic pigs (30±1.8 kg) ventricular fibrillation was induced electrically. After 3 minutes of no-flow, mechanical chest compressions (5cm @ 100 min -1 ) were started. During four 5-minute segments of CPR we measured CO, EtCO 2 , perfusion pressures, carotid and cerebral cortical microcirculatory blood flow (MBF) and CPP (the average of the positive pressure difference between decompression aortic pressure (AP) and right atrial pressure (RAP)) at minute 2 and 4. Interventions were provided in a randomized sequence with PLR vs supine position, with or without epinephrine (0.5mg iv). Values are given as mean±standard deviation. Results: PLR did not increase EtCO2 compared to supine position (3.1±0.7 vs 3.0±0.8 kPa), but CO was minimally increased from 1.1±0.3 to 1.2±0.3 Lmin -1 ,(p=0.003). PLR did not significantly increase AP (57±15 vs. 48±18 mmHg, p=0.3), but RAP was higher (43±10 vs. 31±7, p=0.003). However, no difference was found in CPP due to marked variation in both groups (median(range): PLR 20 (9,43) and supine 17(9,58)). The effect of epinephrine during this experimental setup was minimal. Conclusion: We did not find a positive effect of PLR during experimental ALS, but there were no obviously detrimental effects either.

scholarly journals A Survey of Marker-Less Tracking and Registration Techniques for Health & Environmental Applications to Augmented Reality and Ubiquitous Geospatial Information Systems

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2997 ◽  
Author(s):  
Abolghasem Sadeghi-Niaraki ◽  
Soo-Mi Choi
Keyword(s):  
Information Systems ◽  
Augmented Reality ◽  
Real World ◽  
Spatial Data ◽  
Environmental Applications ◽  
Geospatial Information ◽  
Environmental Application ◽  
The Real ◽  
Advantages And Disadvantages ◽  
Geospatial Information Systems

Most existing augmented reality (AR) applications are suitable for cases in which only a small number of real world entities are involved, such as superimposing a character on a single surface. In this case, we only need to calculate pose of the camera relative to that surface. However, when an AR health or environmental application involves a one-to-one relationship between an entity in the real-world and the corresponding object in the computer model (geo-referenced object), we need to estimate the pose of the camera in reference to a common coordinate system for better geo-referenced object registration in the real-world. New innovations in developing cheap sensors, computer vision techniques, machine learning, and computing power have helped to develop applications with more precise matching between a real world and a virtual content. AR Tracking techniques can be divided into two subcategories: marker-based and marker-less approaches. This paper provides a comprehensive overview of marker-less registration and tracking techniques and reviews their most important categories in the context of ubiquitous Geospatial Information Systems (GIS) and AR focusing to health and environmental applications. Basic ideas, advantages, and disadvantages, as well as challenges, are discussed for each subcategory of tracking and registration techniques. We need precise enough virtual models of the environment for both calibrations of tracking and visualization. Ubiquitous GISs can play an important role in developing AR in terms of providing seamless and precise spatial data for outdoor (e.g., environmental applications) and indoor (e.g., health applications) environments.

Correlation of heat output and blood flow in the finger, especially in cold-induced vasodilation

1960 ◽  
Vol 15 (2) ◽  
pp. 201-208 ◽  
Author(s):  
Merrill Edwards ◽  
Alan C. Burton
Keyword(s):  
Blood Flow ◽  
Heat Loss ◽  
Bath Temperature ◽  
Heat Output ◽  
Deep Body Temperature ◽  
Blood Temperature ◽  
Cold Blood ◽  
The Subject ◽  
Thermal Lag ◽  
Deep Body

A combined finger-plethysmograph and gradient calorimeter has been devised, especially to study cold-induced vasodilation in the finger. By using an electrical heater and a flow-heater it was shown that the thermal lag depends on thermal capacities, conductivities and temperature distribution, so that heat loss and flow are correlated only in the steady state. The actual drop of blood temperature from inflow to outflow was calculated. Results were: a) skin temperature was a better estimate of outflow than bath temperature, b) with general vasodilation, the inflow temperature was close to deep body temperature, but c) with vasoconstriction, digital arterial temperature might be as low as 14°C, and the calculated minimum blood flow (Greenfield) 70% too low. Plethysmography was possible during the hunting reaction in spite of a 30% decrease in venous distensibility. When the subject was cold, blood flow and heat loss, both in constriction and dilation phases, were reduced two or three times, probably due to the increased viscosity of blood. Submitted on August 3, 1959

Leveraging Existing Knowledge to Match Industry Expectations

2020 ◽  
pp. 32-48
Author(s):  
Ilana Lavy
Keyword(s):  
Information Systems ◽  
Real World ◽  
Social Infrastructure ◽  
Knowledge And Skills ◽  
Professional Activities ◽  
Job Seeking ◽  
Academic Knowledge ◽  
Advantages And Disadvantages ◽  
Workplace Environments ◽  
Professional Aspirations

During the last four years, information systems graduates participated in a practicum project during their last study year and took part in various professional activities in the industry in accordance with their professional aspirations and their desired specialty. The main purpose of this project was to reduce the gap between the graduates' acquired academic knowledge and the industry expectations. The aim of this chapter was to reveal the graduates' perceived contributions of the project. For that matter, semi-structured questionnaires and interviews with graduates who participated in the project in the last four years were conducted. The graduates experienced real workplace environments, acquired extended knowledge and skills, built social infrastructure to assist them with future job seeking, and above all gained real-world experience that helps them to build their professional image, and gain confidence in their traits and abilities. In addition, the practicum-based approach was compared with other common approaches used to bridge the gap, and its relative advantages and disadvantages were discussed.

scholarly journals Frontal EEG Changes with the Recovery of Carotid Blood Flow in a Cardiac Arrest Swine Model

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3052
Author(s):  
Heejin Kim ◽  
Ki Hong Kim ◽  
Ki Jeong Hong ◽  
Yunseo Ku ◽  
Sang Do Shin ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Circulation ◽  
Life Support ◽  
Spontaneous Circulation ◽  
Swine Model ◽  
Carotid Blood Flow ◽  
Non Invasive ◽  
Entropy Measures ◽  
Palpable Pulse ◽  
Eeg Changes

Monitoring cerebral circulation during cardiopulmonary resuscitation (CPR) is essential to improve patients’ prognosis and quality of life. We assessed the feasibility of non-invasive electroencephalography (EEG) parameters as predictive factors of cerebral resuscitation in a ventricular fibrillation (VF) swine model. After 1 min untreated VF, four cycles of basic life support were performed and the first defibrillation was administered. Sustained return of spontaneous circulation (ROSC) was confirmed if a palpable pulse persisted for 20 min. Otherwise, one cycle of advanced cardiovascular life support (ACLS) and defibrillation were administered immediately. Successfully defibrillated animals were continuously monitored. If sustained ROSC was not achieved, another cycle of ACLS was administered. Non-ROSC was confirmed when sustained ROSC did not occur after 10 ACLS cycles. EEG and hemodynamic parameters were measured during experiments. Data measured for approximately 3 s right before the defibrillation attempts were analyzed to investigate the relationship between the recovery of carotid blood flow (CBF) and non-invasive EEG parameters, including time- and frequency-domain parameters and entropy indices. We found that time-domain magnitude and entropy measures of EEG correlated with the change of CBF. Further studies are warranted to evaluate these EEG parameters as potential markers of cerebral circulation during CPR.

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