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Article
Publication date: 20 October 2021

Doaa H. Elgohary, Tamer F. Khalifa, Mona M. Salem, Nermin M. Aly, Elham Hassan and Ashraf A. Shamaa

The purpose of this work is to perform an application study on experimental animals (dogs) to investigate the efficiency of using weft knitted mesh fabric as cardiac support mesh…

Abstract

Purpose

The purpose of this work is to perform an application study on experimental animals (dogs) to investigate the efficiency of using weft knitted mesh fabric as cardiac support mesh to support left ventricular hypertrophy.

Design/methodology/approach

In this work, weft-knitted mesh sample “Knitted Cardiac Support Mesh” manufactured using Nylon (6, 6) yarns, with count 20 Denier and medium mesh size, was placed around the two ventricles to prevent further dilatation, support and reduce left ventricular wall stress.

Findings

Medical textile is a rapidly expanding field in technical textiles that are widely used in a variety of medical applications. One of these medical textile applications is “Knitted Cardiac Support Mesh”, which is used in the treatment of Dilated Cardiomyopathy.

Originality/value

After the implantation of the manufactured Knitted Cardiac Support Mesh around the myocardium, all dogs survived for three months before being euthanized, and some clinical examinations were performed to investigate and evaluate the sample performance. It was demonstrated from the experimental application, that the nylon mesh sample performed the best during the surgical operation due to its good ability to stretch and recover at a moderate rate, as well as the textile mesh lightweight.

Details

Research Journal of Textile and Apparel, vol. 26 no. 4
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 26 October 2010

Michael Galagudza, Dmitry Korolev, Dmitry Sonin, Viktor Postnov, Garry Papayan, Ivan Uskov, Anastasia Belozertseva and Eugene Shlyakhto

Clinical outcome in patients with ischemic heart disease can be significantly improved with the implementation of targeted drug delivery into the ischemic myocardium. The purpose…

Abstract

Purpose

Clinical outcome in patients with ischemic heart disease can be significantly improved with the implementation of targeted drug delivery into the ischemic myocardium. The purpose of this paper is to review the data of recent literature and present original findings relevant to the problem of therapeutic heart targeting with use of nanoparticles.

Design/methodology/approach

For literature review, a public‐domain database (Medline) was searched using a web‐based search engine (PubMed) and the following key words: “nanoparticles”, “nanocarriers”, and “targeted drug delivery”. Experimental approaches included fabrication of carbon and silica nanoparticles, their characterization and surface modification. The acute hemodynamic effects of nanoparticle formulation as well as nanoparticle biodistribution were studied on male Wistar rats.

Findings

Carbon and silica nanoparticles are biocompatible materials that can be used as carriers for heart‐targeted drug delivery. Concepts of passive and active targeting can be applied to the development of targeted drug delivery to the ischemic myocardial cells.

Originality/value

The present paper is believed to be the first on ligand‐directed targeted drug delivery into the damaged myocardium.

Details

Journal of Manufacturing Technology Management, vol. 21 no. 8
Type: Research Article
ISSN: 1741-038X

Keywords

Article
Publication date: 9 September 2019

Marcello Iasiello, Assunta Andreozzi, Nicola Bianco and Kambiz Vafai

Recently, the porous media theory has been successively proposed for many bioengineering applications. The purpose of this paper is to analyze if the porous media theory can be…

Abstract

Purpose

Recently, the porous media theory has been successively proposed for many bioengineering applications. The purpose of this paper is to analyze if the porous media theory can be applied to model radiofrequency (RF) cardiac ablation.

Design/methodology/approach

Blood flow, catheter and tissue are modeled. The latter is further divided into a fluid and a solid phase, and porous media equations are used to model them. The heat source term is modeled using the Laplace equation, and the finite element method is used to solve the governing equations under the appropriate boundary conditions and closure coefficients.

Findings

After validation with available literature data, results are shown for different velocities and applied voltages to understand how these parameters affect temperature fields (and necrotic regions).

Research limitations/implications

The model might require further validation with experiments under different conditions after comparisons with available literature. However, this might not be possible due to the experimental complexity.

Practical implications

The improvement in predictions from the model might help the final user, i.e. the surgeon, who uses cardiac ablation to treat arrhythmia.

Originality/value

This is the first time that the porous media theory is applied to RF cardiac ablation. The robustness of the model, in which many variables are taken into account, makes it suitable to better predict temperature fields, and damaged regions, during RF cardiac ablation treatments.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 14 November 2023

Mostafa Abbaszadeh, AliReza Bagheri Salec and Shurooq Kamel Abd Al-Khafaji

The space fractional PDEs (SFPDEs) play an important role in the fractional calculus field. Proposing a high-order, stable and flexible numerical procedure for solving SFPDEs is…

Abstract

Purpose

The space fractional PDEs (SFPDEs) play an important role in the fractional calculus field. Proposing a high-order, stable and flexible numerical procedure for solving SFPDEs is the main aim of most researchers. This paper devotes to developing a novel spectral algorithm to solve the FitzHugh–Nagumo models with space fractional derivatives.

Design/methodology/approach

The fractional derivative is defined based upon the Riesz derivative. First, a second-order finite difference formulation is used to approximate the time derivative. Then, the Jacobi spectral collocation method is employed to discrete the spatial variables. On the other hand, authors assume that the approximate solution is a linear combination of special polynomials which are obtained from the Jacobi polynomials, and also there exists Riesz fractional derivative based on the Jacobi polynomials. Also, a reduced order plan, such as proper orthogonal decomposition (POD) method, has been utilized.

Findings

A fast high-order numerical method to decrease the elapsed CPU time has been constructed for solving systems of space fractional PDEs.

Originality/value

The spectral collocation method is combined with the POD idea to solve the system of space-fractional PDEs. The numerical results are acceptable and efficient for the main mathematical model.

Details

Engineering Computations, vol. 40 no. 9/10
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 12 December 2018

Shokoofeh Talebi, Zamzam Paknahad, Mohammad Hashemi and Akbar Hasanzadeh

Coronary artery disease (CAD) is developed by an insufficient supply of oxygen-rich blood to the myocardium. Recent studies have shown that increased oxidative stress has…

Abstract

Purpose

Coronary artery disease (CAD) is developed by an insufficient supply of oxygen-rich blood to the myocardium. Recent studies have shown that increased oxidative stress has implicated in the pathogenesis of coronary atherosclerosis. Anxiety and CAD have a mutual relationship, as the effect of long-lasting anxiety on atherosclerosis and CAD is well known. The purpose of this study is to investigate the relationship between dietary / serum total antioxidant capacity and CAD.

Design/methodology/approach

A total of 160 male patients were enrolled in this cross-sectional study. Diagnosis and analysis of angiograms were performed visually by a cardiologist. The subjects were categorized into CAD− (coronary artery obstruction <75 per cent) and CAD+ (coronary artery obstruction ≥ 75 per cent) groups. Anthropometric indices, blood pressure, blood sugar and lipid profile and physical activity (PA) were assessed. Information about anxiety was obtained by Spielberger questionnaire. Dietary total antioxidant capacity (TAC) was obtained by using a semi-quantitative food frequency questionnaire and an oxygen radical absorbance capacity of selected foods.

Findings

Mean of dietary TAC was significantly lower in CAD+ than CAD− group (P < 0.001). However, there was not any significant differences about serum TAC (P = 0.28). The mean of body mass index (BMI) (P = 0.04) and triglyceride (TG) level (P = 0.03) and the frequency of smoking (P = 0.03) were significantly higher in the CAD+ than the CAD− group. There was no significant relationship between CAD with apparent (P = 0.33) and hidden anxiety level (P = 0.16). Confounding factors such as smoking and medications were adjusted.

Research limitations/implications

This study had certain limitations. Being a single center cross-sectional design does not permit analysis of causal relationships; the sample size was geographically limited. The authors could not exclude the medication of patients, which could affect the total antioxidant capacity levels. Measurement error in self-reported dietary consumption may results misclassification of exposure.

Practical implications

A diet high in total antioxidant capacity is inversely associated with CAD. Serum TAC does not vary between men with and without CAD when confounders including age, BMI, TG, smoking, SBP, DBP, energy intake, PA, HDL-C, LDL-C, T-C, FBS, family history of CAD, education and anxiety are taken into consideration.

Social implications

High consumption of vegetables and fruits may play a major role in the prevention of CAD.

Originality/value

The study was approved by the ethics committee of Isfahan University of Medical Sciences (No:394888).

Details

Nutrition & Food Science, vol. 49 no. 4
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 1 April 1992

JAROSLAV MACKERLE

This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary element (BE…

Abstract

This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary element (BE) applications in different fields of biomechanics between 1976 and 1991. The aim of this paper is to help the users of FE and BE techniques to get better value from a large collection of papers on the subjects. Categories in biomechanics included in this survey are: orthopaedic mechanics, dental mechanics, cardiovascular mechanics, soft tissue mechanics, biological flow, impact injury, and other fields of applications. More than 900 references are listed.

Details

Engineering Computations, vol. 9 no. 4
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 September 2001

P. Wach, R. Modre, B. Tilg and G. Fischer

A promising approach for the solution of the electrocardiographic inverse problem is the calculation of the cardiac activation sequence from body surface potential (BSP) mapping…

Abstract

A promising approach for the solution of the electrocardiographic inverse problem is the calculation of the cardiac activation sequence from body surface potential (BSP) mapping data. Here, a two‐fold regularization scheme is applied in order to stabilize the inverse solution of this intrinsically ill‐posed problem. The solution of the inverse problem is defined by the minimum of a non‐linear cost function. The L‐curve method can be applied for regularization parameter determination. Solving the optimization problem by a Newton‐like method, the L‐curve may be of pronged shape. Then a numerically unique determination of the optimal regularization parameter will become difficult. This problem can be avoided applying an iterative linearized algorithm. It is shown that activation time imaging due to temporal and spatial regularization is stable with respect to large model errors. Even neglecting cardiac anisotropy in activation time imaging results in an acceptable inverse solution.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 20 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 4 February 2014

Husayn Al Mahdy

The aim of this paper was, principally, to look at the coroner's post-mortem report quality regarding adult medical patients admitted to an English hospital; and to compare…

Abstract

Purpose

The aim of this paper was, principally, to look at the coroner's post-mortem report quality regarding adult medical patients admitted to an English hospital; and to compare results with Royal College of Pathologists guidelines.

Design/methodology/approach

Hospital clinical notes of adult medical patients dying in 2011 and who were referred to the coroner's office to determine the cause of death were scrutinised. Their clinical care was also reviewed.

Findings

There needs to be a comprehensive approach to coroner's post-mortems such as routinely taking histological and microbiological specimens. Acute adult medical patient care needs to improve.

Research limitations/implications

Steps should be taken to ensure that comprehensive coroner's post-mortems are performed throughout the UK, including with routine histological and microbiological specimens examination. Additionally, closer collaboration between clinicians and pathologists needs to occur to improve emergency adult medical patient clinical care.

Originality/value

The study highlights inadequacies in coroner's pathology services.

Details

International Journal of Health Care Quality Assurance, vol. 27 no. 1
Type: Research Article
ISSN: 0952-6862

Keywords

Article
Publication date: 16 January 2020

Juliane Barroso Leal, Juçara Barroso Leal, Joaline Barroso Portela Leal, Yan de Lima Borges, Maria Ivone Leal de Moura, Alfredo Anderson Teixeira-Araujo, Venilson Serafim da Costa and Ferdinando Oliveira Carvalho

This paper aims to verify the effect of 12 weeks of grape juice (GJ) consumption associated with aerobic exercise on the variation of the hypertensive elderly pressure.

Abstract

Purpose

This paper aims to verify the effect of 12 weeks of grape juice (GJ) consumption associated with aerobic exercise on the variation of the hypertensive elderly pressure.

Design/methodology/approach

A total of 45 hypertensive elderly of both sexes were distributed into: control group (CG, n = 10), exercise group (EG, n = 10), juice group (JG, n = 12) and juice and exercise group (JEG, n = 13). Blood pressure and heart rate were checked weekly before exercise in JG and JEG, and before and after intervention in all groups, with JG and JEG supplemented with 200 mL of GJ. Three weekly sessions of moderate walking were applied.

Findings

There was a reduction in EG, JG and JEG for systolic pressure and diastolic only for JG and JEG. The GJ consumption to the practice of aerobic exercise provided reductions in the arterial pressure of hypertensive, in addition to stabilization of the diastolic pressure.

Research limitations/implications

Although the objective of the study was to compare the effect and value of intervention with controls, the study had no intervention in food consumption, which could have led to more significant results. There was a limitation in the control drink, leading the study not to be blind, which may have impaired the results. However, it is probably not a bias, as the groups were divided by residence area, and therefore, had no direct contact with the other groups. Another limitation was that the sample size was still small, which would lead to more reliable results. Finally, although the existing limitations cannot be disregarded, the results of this research are very promising, especially when the objective is the effect of GJ and aerobic exercise on blood pressure, with the possibility of implementing supplemental GJ and the inclusion or not of exercise to the hypertensive elderly.

Originality/value

The paper deals with the benefits of GJ consumption associated with aerobic physical exercise on the blood pressure of elderly hypertensive patients. Considering that GJ along with physical exercise was enough to reduce the blood pressure of hypertensive elderly, this may be a new model to be used to reduce and/or control blood pressure, and GJ and the exercise to be part of the daily life of the population.

Details

Nutrition & Food Science , vol. 50 no. 5
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 10 July 2009

Zsolt Badics and Doron Harlev

The purpose of this paper is to describe a numerical inversion technology developed to reconstruct endocardial electric potential maps on the internal surface of heart chambers…

1050

Abstract

Purpose

The purpose of this paper is to describe a numerical inversion technology developed to reconstruct endocardial electric potential maps on the internal surface of heart chambers utilizing intracavitary multi‐electrode catheter measurements. The objective is to perform the reconstruction real time with high accuracy, thereby allowing the incorporation of the technology into medical imaging systems.

Design/methodology/approach

Electrode potential points from several beats are merged in order to maximize the information extracted from the catheter measurements. To solve the ill‐posed inverse problem fast, numerically stable solution algorithms based on generalized Tikhonov regularization and bidiagonalization are developed. The latter algorithm also provides an efficient framework for choosing the regularization parameter optimally.

Findings

Results of three examples are presented to thoroughly illustrate the performance of the algorithm: one with synthetic data generated in a computational electromagnetics (virtual lab) environment, thereby allowing exact error analysis; another with measured data from a phantom‐bench human heart model where the effect of measurement errors can be investigated in a controlled environment; and a third example that illustrates how the algorithm performs when the catheter data are collected in vivo in a swine heart.

Practical implications

The speed and accuracy in the three examples successfully prove that the inversion technology can be a key component of medical imaging systems.

Originality/value

While some elements of these computational models and techniques presented have been used for decades, the authors achieve speed and accuracy that have not been reported before by combining multi‐beat catheter measurements, the generalized Tikhonov regularization technique, a bidiagonalization algorithm and other top‐notch linear algebra techniques.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 28 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

1 – 10 of 54