A Multi-Scale Flow Model for Studying Blood Circulation in Vascular System

2020 ◽  
pp. 743-751
Author(s):  
Ulin Nuha Abdul Qohar ◽  
Antonella Zanna Munthe-Kaas ◽  
Jan Martin Nordbotten ◽  
Erik Andreas Hanson
Keyword(s):  
Blood Circulation ◽  
Flow Model ◽  
Vascular System ◽  
Multi Scale

scholarly journals A nonlinear multi-scale model for blood circulation in a realistic vascular system

2021 ◽  
Vol 8 (12) ◽  
Author(s):  
Ulin Nuha A. Qohar ◽  
Antonella Zanna Munthe-Kaas ◽  
Jan Martin Nordbotten ◽  
Erik Andreas Hanson
Keyword(s):  
Blood Flow ◽  
Blood Circulation ◽  
Vascular System ◽  
Scale Model ◽  
Model Framework ◽  
Fluid Exchange ◽  
Multi Scale ◽  
Proposed Model ◽  
Porous Media Model ◽  
Capillary Bed

In the last decade, numerical models have become an increasingly important tool in biological and medical science. Numerical simulations contribute to a deeper understanding of physiology and are a powerful tool for better diagnostics and treatment. In this paper, a nonlinear multi-scale model framework is developed for blood flow distribution in the full vascular system of an organ. We couple a quasi one-dimensional vascular graph model to represent blood flow in larger vessels and a porous media model to describe flow in smaller vessels and capillary bed. The vascular model is based on Poiseuille’s Law, with pressure correction by elasticity and pressure drop estimation at vessels' junctions. The porous capillary bed is modelled as a two-compartment domain (artery and venous) using Darcy’s Law. The fluid exchange between the artery and venous capillary bed compartments is defined as blood perfusion. The numerical experiments show that the proposed model for blood circulation: (i) is closely dependent on the structure and parameters of both the larger vessels and of the capillary bed, and (ii) provides a realistic blood circulation in the organ. The advantage of the proposed model is that it is complex enough to reliably capture the main underlying physiological function, yet highly flexible as it offers the possibility of incorporating various local effects. Furthermore, the numerical implementation of the model is straightforward and allows for simulations on a regular desktop computer.

scholarly journals Experimental Evaluation of the Effectiveness of Aspiration-Based Techniques to Treat Different Types of Acute Thromboembolic Occlusions in the Femoropopliteal Vascular System Using an In Vitro Flow Model

2021 ◽  
Author(s):  
Schekeb Aludin ◽  
Philipp Jost Schäfer ◽  
Christoph Borzikowsky ◽  
Olav Jansen ◽  
Julian Pfarr ◽  
...  
Keyword(s):  
Femoral Artery ◽  
Flow Model ◽  
Vascular System ◽  
Laser System ◽  
In Vitro Study ◽  
Stent Retriever ◽  
Different Types ◽  
First Pass ◽  
Mechanical Fragmentation

Abstract Purpose In this in vitro study, the effectiveness and safety of four aspiration-based techniques for thrombectomy are evaluated for three types of thrombi in a flow model simulating the femoropopliteal segment. Material and Methods Red, white, and mixed thrombi were produced in a standardized manner and used to simulate occlusion of a superficial femoral artery using a pulsatile flow model. Four techniques were compared: aspiration alone, aspiration + stent retriever, exposing thrombus to laser by an excimer laser system and a laser catheter + aspiration, and aspiration + mechanical fragmentation by a separator. Rate of first-pass recanalization, embolic events, and number of embolized fragments > 1 mm were compared. Results Aspiration alone, stent retriever, laser, and separator differed in rates of first-pass recanalization (53.3%; 86.6%; 20%; and 100%) and embolic events (40%; 93.3%; 73.3%; and 60%). Number of embolized fragments was lowest with aspiration and higher with separator, laser, and stent retriever. Rates of first-pass-recanalization (75%; 75%; and 45%) and embolic events (65%; 60%; and 75%) differed for red, white, and mixed thrombi. The mixed thrombus caused the highest number of embolized fragments, which was particularly high using the stent retriever. Conclusion Additional use of mechanical techniques significantly enhances the effectiveness of thrombectomy but simultaneously provokes more embolism. Laser seems to negatively alter the structure of a thrombus and thus diminishes the effectiveness, while provoking embolism. All techniques had lowest effectiveness, but highest embolism with the mixed thrombus. This was particularly striking when a stent retriever was used with the mixed thrombus.

scholarly journals A multi-scale flow model for blood regulation in a realistic vascular system

2020 ◽  
Author(s):  
Ulin Nuha Abdul Qohar ◽  
Antonella Zanna Munthe-Kaas ◽  
Jan Martin Nordbotten ◽  
Erik Andreas Hanson
Keyword(s):  
Blood Flow ◽  
Blood Circulation ◽  
Numerical Models ◽  
Scale Model ◽  
Fluid Exchange ◽  
Desktop Computer ◽  
Multi Scale ◽  
Proposed Model ◽  
Porous Media Model ◽  
Capillary Bed

Abstract In the last decade, numerical models have been an increasingly important tool in medical science both for the fundamental understanding of the physiology of the human body as well as for diagnostics and personalized medicine. In this paper, a multi-scale model is developed for blood flow and regulation in a full vascular structure of an organ. We couple a 1D vascular graph model to represent blood flow in larger vessels and a porous media model to describe flow in smaller vessels and capillary bed. The vascular model is based on Poiseuille’s law, with pressure correction by elasticity and pressure drop estimation at vessels junctions. The porous capillary bed is modeled as a two compartments domain (arterial and venal) and Darcy’s law. The fluid exchange between the arterial and venal capillary bed compartments is defined as blood perfusion. The numerical experiments show that the proposed model for blood circulation: 1) is closely dependent on the structure and parameters of both the vascular vessels and of the capillary bed, and 2) it provides a realistic blood circulation in the organ. The advantage of the proposed model is that it is complex enough to capture the underlying physiology reliably, yet highly flexible as it offers the possibility of incorporating various local effects. Furthermore, the numerical implementation of the model is straightforward and allows for simulations on a regular desktop computer.

scholarly journals A new framework for assessing subject-specific whole brain circulation and perfusion using MRI-based measurements and a multi-scale continuous flow model

2019 ◽  
Vol 15 (6) ◽  
pp. e1007073 ◽  
Author(s):  
Erlend Hodneland ◽  
Erik Hanson ◽  
Ove Sævareid ◽  
Geir Nævdal ◽  
Arvid Lundervold ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Flow Model ◽  
Brain Circulation ◽  
Whole Brain ◽  
Multi Scale ◽  
Subject Specific ◽  
New Framework

Materialflussmodelle für die HiL-Simulation*/Material Flow Models for HiL-Simulation – Simulating the material flow of machines in a Hardware-in-the-Loop simulation

2016 ◽  
Vol 106 (03) ◽  
pp. 119-124
Author(s):  
C. Scheifele ◽  
A. Lechler ◽  
A. Prof. Verl
Keyword(s):  
Material Flow ◽  
Flow Model ◽  
Movement Behavior ◽  
Hardware In The Loop ◽  
Flow Models ◽  
Multi Scale ◽  
Time Requirements ◽  
Machine Simulation ◽  
Hard Real Time ◽  
Hil Simulation

Bei einer Hardware-in-the-Loop (HiL)-Simulation wird die reale Steuerungstechnik mit einer experimentierfähigen Maschinensimulation verbunden. Soll das Bewegungsverhalten des Materialflusses in der Maschinensimulation zur Generierung von Steuerungssignalen berechnet werden, so müssen die harten Echtzeitanforderungen einer HiL-Simulation eingehalten werden. Dieser Beitrag betrachtet verschiedene Materialflussmodelle und gibt das Ziel eines mehrskaligen Simulationsmodells für die HiL-Simulation vor.   A Hardware-in-the-Loop (HiL) simulation couples real control technology with an experimental machine simulation. When computing the movement behavior of a material flow in the machine simulation to generate control signals, the hard real-time requirements of a HiL-simulation must be considered. This article checks different material flow models and defines the objective of a multi-scale material flow model for HiL-Simulation.

Time of complete blood circulation, method of determination and changes under the influence of carbon dioxide baths

1935 ◽  
Vol 31 (8-9) ◽  
pp. 977-981
Author(s):  
I. M. Sribner ◽  
M. Ya. Basok
Keyword(s):  
Carbon Dioxide ◽  
Blood Circulation ◽  
Vascular System ◽  
Circulation Method ◽  
Method Of Determination ◽  
Energy Accounting ◽  
Main Thing ◽  
The Individual ◽  
Case Basis

In studying the physiology and pathology of blood circulation, and in dealing with the individual issues involved, we aim to find out on a case-by-case basis how far enough blood is supplied to cells and tissues to deliver nutrient material and oxygen. Therefore, the main thing we are interested in when analysing the factors that make up the blood circulation function is the energy accounting with which the blood moves through the vascular system.

scholarly journals Adaptive Multi-Scale Shallow Flow Model: a Wavelet-Based Formulation

10.29007/vm3q ◽  
2018 ◽  
Author(s):  
Georges Kesserwani ◽  
Mohammad Kazem Sharifian ◽  
James Shaw
Keyword(s):  
Flow Model ◽  
Adaptive Mesh ◽  
Mesh Adaptivity ◽  
Wavelet Bases ◽  
Multi Scale ◽  
Wide Range ◽  
Mesh Resolution ◽  
Local Solutions ◽  
Flow Variables ◽  
Shallow Flow Model

This work outlines the use of wavelet bases to re-formulate a finite volume (FV) local solution of the shallow water equations (SWEs), so as to achieve mesh adaptivity via local compression and truncation of the numerical solution’s details across successive resolution scales with reference to a single threshold error set by the user. The wavelet bases naturally lead to a scalable FV formulation and how they can readily be exploited to achieve adaptive mesh-resolution selection: up-scaling and/or down- scaling by means of the local solutions’ data (i.e. both flow variables and terrain). Our results show a notable promise in using wavelets as a basis for future flood models to achieve conservative and more autonomous simulation at a wide range of length-scales.

scholarly journals To the microanatomy of the spleen

2020 ◽  
Vol 26 (5-6) ◽  
pp. 551-556
Author(s):  
N. K. Goryaev ◽  
R. M. Akhrem-Akhremovich
Keyword(s):  
Blood Circulation ◽  
Vascular System ◽  
Point Of View ◽  
Portal Circulation

From a physiological point of view, the spleen has recently attracted special attention as a reserve reservoir of blood. In view of the ability to independently actively change to a very large extent its volume and blood circulation, the spleen is of no small importance as a factor that can significantly affect the overall blood circulation in the vascular system, as well as on the portal circulation.

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