scholarly journals Numerical analysis of blood flow in intracranial artery stenosis affected by ischemic stroke using Finite Element method

2019 ◽  
Vol 1218 ◽  
pp. 012005
Author(s):  
A Fatahillah ◽  
S Setiawani ◽  
A S Mandala ◽  
S Suharto ◽  
R P Murtikusuma ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Blood Flow ◽  
Ischemic Stroke ◽  
Numerical Analysis ◽  
Artery Stenosis ◽  
Intracranial Artery ◽  
Intracranial Artery Stenosis ◽  
Element Method

scholarly journals Bypass Surgery for Ischemic Stroke Caused by Intracranial Artery Stenosis or Occlusion

2018 ◽  
Vol 4 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Ismatullah Soufiany ◽  
Khalil Ahmad Hijrat ◽  
Spina Soufiany ◽  
Lukui Chen
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Artery ◽  
Vegetative State ◽  
Superficial Temporal Artery ◽  
Case Series ◽  
Temporal Artery ◽  
Artery Stenosis ◽  
Intracranial Stenosis ◽  
Intracranial Artery ◽  
Intracranial Artery Stenosis

Surgical revascularization may be beneficial in patients with ischemic stroke caused by intracranial stenosis or occlusion who are ineligible for thrombolysis. Objective To evaluate the outcome of superficial temporal artery to middle cerebral artery (STA-MCA) bypass in ischemic stroke caused by intracranial artery stenosis or occlusion. Methods We retrospectively studied successive case series of 19 patients who underwent surgical treatment between 2013–2017 of STA-MCA bypass. Surgical procedure was performed for the patients with acute ischemic stroke who were ineligible for thrombolysis. Results Of the 19 patients enrolled, symptom aggravation occurred during medical treatment, the patients were ineligible for thrombolysis despite being within 8 hours of symptom onset. Bypass significantly improved National Institutes of Health Stroke Scale scores, mean patient age was 78.05 years (range, 39–78 y). However, male 11 (57.95%) out of nineteen patients were presented with left-sided-lesions while female 8 (42%) had right-sided lesions with significant infarction growth by diffusion weighted imaging achieved, after surgical maneuver. No major complications occurred intraoperatively, in contrast to 2 (10.5%) minor manifestation were suffering minor complications probably they included the remote infarction (posterior cerebral artery territory). Pooled analysis with our patients showed a significant neurological improvement and a good outcome in 13 (68.4%) patients without hemorrhage or any other complication, 6 (31.6%) patients with unfavorable outcome (severe disability 2; vegetative state 4, non of them are died 0;). Conclusion STA-MCA bypass may be beneficial to patients with acute stroke or stenosis in progress who are ineligible for medical therapy. Furthermore, it appears safe when the infarction is small. These findings indicate that STA-MCA bypass could be considered as a treatment option in selected patients with ischemic stroke caused by intracranial stenosis or occlusion.

NUMERICAL ANALYSIS OF THE FINITE ELEMENT METHOD APPLIED TO THE BOLTZMANN-POISSON SYSTEM

1995 ◽  
Vol 05 (03) ◽  
pp. 351-365 ◽  
Author(s):  
V. SHUTYAEV ◽  
O. TRUFANOV
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Semiconductor Device ◽  
Initial Boundary ◽  
Initial Boundary Value Problem ◽  
Poisson System ◽  
The Finite Element Method ◽  
Initial Boundary Value ◽  
Element Method

This paper is concerned with the numerical analysis of the mathematical model for a semiconductor device with the use of the Boltzmann equation. A mixed initial-boundary value problem for nonstationary Boltzmann-Poisson system in the case of one spatial variable is considered. A numerical algorithm for solving this problem is constructed and justified. The algorithm is based on an iterative process and the finite element method. A numerical example is presented.

Finite Element Method-based geomechanical risk assessment of underground laboratory located in the deep copper mine

2021 ◽  
Author(s):  
Krzysztof Fulawka ◽  
Witold Pytel ◽  
Piotr Mertuszka ◽  
Marcin Szumny
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
New Technologies ◽  
Radiation Detection ◽  
Underground Laboratory ◽  
Design Stage ◽  
Copper Mine ◽  
Geophysical Surveys ◽  
Element Method

<p>Underground laboratories provide a unique environment for various industries and are a suitable place for developing new technologies for mining, geophysical surveys, radiation detection, as well as many other studies and measurements. Unfortunately, any operation in underground excavations is associated with exposure to many hazards not necessarily encountered in surface laboratories. One of the most dangerous events observed in underground conditions is the dynamic manifestation of rock mass pressure in form of rockburst, roof falls and mining tremors. Therefore, proper evaluation of geomechanical risk is a key element ensuring the safety of work in underground conditions. Finite Element Method-based numerical analysis is one of the tools which allow conducting a detailed geomechanical hazard assessment already at the object design stage. The results of such calculations may be the basis for the implementation of preventive measures before running up the underground facility.</p><p>Within this paper, the three-dimensional FEM-based numerical analysis of large-scale underground laboratory located in deep Polish copper mine was presented. The calculations were made with GTS NX software, which allowed determining the changes in the safety factor in surrounding of the analyzed area. Finally, the possibility of underground laboratory establishment, with respect to predicted stress and strain conditions, were determined.</p>

Abstract T P101: Low Serum Eicosapentaenoic Acid- Arachidonic Acid Ratio is Associated With Intracranial Stenosis in Patients With Acute Ischemic Stroke

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Yuko Abe ◽  
Ryoichi Otsubo ◽  
Sho Murase ◽  
Kenichiro Nakazawa ◽  
Kazuo Kitagawa
Keyword(s):  
Risk Factors ◽  
Arachidonic Acid ◽  
Ischemic Stroke ◽  
Eicosapentaenoic Acid ◽  
Acute Ischemic Stroke ◽  
Artery Stenosis ◽  
Intracranial Artery ◽  
Stroke Subtype ◽  
Fa Composition ◽  
Intracranial Artery Stenosis

Purpose: A low ratio of serum eicosapentaenoic acid to arachidonic acid (EPA/AA) has been associated with atherosclerotic disease. Few studies investigate the association of serum fatty acid (FA) composition with the acute ischemic stroke so far. Our aim of this study is to evaluate the relationships between FA composition and stroke subtypes, extra-/intracranial atherosclerotic stenoses, and other cerebrovascular indicators Methods: This study included 154 consecutive patients who were admitted to our hospital because of acute ischemic stroke between April 2011 and March 2012. We examined the FA composition and classical vascular risk factors. We conducted brain MRI/MRA, carotid ultrasonogram, transthoracic echocardiogram, 24hr Holter electrocardiogram, ankle brachial index (ABI) and pulse wave velocity (PWV) in order to evaluate the severity of atherosclerotic change, stroke subtype, and cardiovascular status. Results: The mean value of EPA/AA was 0.33±0.22 in all patients with acute cerebral infarction. The 154 patients in this study (mean age 71 years) were categorized as follows; large artery atherosclerosis (LA; n=57), small artery occlusion (SA; n=48), cardiogenic embolism (CE; n=18), and others (n=31). We found intracranial artery stenosis greater than 50% in 70 patients (45%). The intracranial artery stenosis was associated with low EPA/AA ratio (P=0.013) and low EPA concentration (P=0.013). This association remained significant (P<0.05) after controlling for classical atherosclerotic risk factors. We could not find a significant correlation between FA composition and stroke subtype. However, there was a tendency for the EPA/AA ratio of LA patients to be the lowest among all subtype groups. The EPA/AA ratio was not associated with ABI, PWV, prevalence of arrhythmia, or cardiac function. Conclusions: A low EPA/AA ratio was significantly associated with intracranial stenosis in patients with acute ischemic stroke. This study shows the EPA/AA ratio might be an important marker to reflect the cerebral artery stenosis.

A Numerical Analysis for Cracks Emanating from a Quarter-Spherical Cavity on the Edge of an Elastic Body

2012 ◽  
Vol 499 ◽  
pp. 243-247
Author(s):  
Long Hai Yan ◽  
Bao Liang Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Elastic Body ◽  
Spherical Cavity ◽  
Numerical Results ◽  
Shielding Effect ◽  
Corner Crack ◽  
Element Method

This note is specifically concerned with cracks emanating from a quarter-spherical cavity on the edge in an elastic body (see Fig.1) by using finite element method. The numerical results show that the existence of the cavity has a shielding effect of the corner crack. In addition, it is found that the effect of boundaries parallel to the crack on the SIFs is obvious when.H/R≤3

Plasma Levels of Apolipoprotein E and Risk of Intracranial Artery Stenosis in Acute Ischemic Stroke Patients

2013 ◽  
Vol 62 (1) ◽  
pp. 26-31 ◽  
Author(s):  
Yong-Jae Kim ◽  
Seung-Min Lee ◽  
Hyun-Ji Cho ◽  
Hyun Ju Do ◽  
Chang Hyung Hong ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Apolipoprotein E ◽  
Acute Ischemic Stroke ◽  
Plasma Levels ◽  
Artery Stenosis ◽  
Intracranial Artery ◽  
Stroke Patients ◽  
Intracranial Artery Stenosis
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