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Cyron C J CJ Department of Biomedical Engineering Yale University, New Haven, CT, 06520, - - 2014
Vascular mechanics has been studied in depth since the early 1970s mainly following classical concepts from continuum mechanics. Yet, an important distinction of blood vessels, in contrast to typical engineering materials, is the continuous degradation and deposition of material in these living tissues. In this paper we examine mechanical consequences ...
Oyama Kenichi K Department of Neurological Surgery, The Ohio State University Wexner Medical Center, 410 West 10th Avenue, Columbus, OH, 43210, USA, - - 2014
Mastery of the expanded endoscopic endonasal approach (EEA) requires anatomical knowledge and surgical skills; the learning curve for this technique is steep. To a great degree, these skills can be gained by cadaveric dissections; however, ethical, religious, and legal considerations may interfere with this paradigm in different regions of the ...
Naik Naren - - 2014
The dynamic reconstruction problem in tomographic imaging is encountered in several applications, such as species determination, the study of blood flow through arteries/veins, motion compensation in medical imaging, and process tomography. The reconstruction method of choice is the Kalman filter and its variants, which, however, are faced by issues of ...
Kwon Soon-Sung SS Department of Mechanical and Biomedical Engineering, Kangwon National University, 192-1, Hyoja 2-dong, Chuncheon, Kangwon, 200-701, Republic of - - 2014
The fractional flow reserve (FFR) is a widely used clinical index to evaluate the functional severity of coronary stenosis. A computer simulation method based on patients' computed tomography (CT) data is a plausible non-invasive approach for computing the FFR. This method can provide a detailed solution for the stenosed coronary ...
Karanasos Antonios A Department of Interventional Cardiology, Thoraxcentre, BA-585, Erasmus University Medical Centre, Gravendijkwal 230, 3015 CE Rotterdam, The - - 2014
In coronary bifurcations assessment, evaluation of side-branch (SB) ostia by an optical coherence tomography (OCT) pullback performed in the main branch (MB) could speed up lesion evaluation and minimize contrast volume. Dedicated software that reconstructs the cross-sections perpendicular to the SB centreline could improve this assessment. We aimed to validate ...
Ovcharenko E A EA Research Institute for Complex Issues of Cardiovascular Diseases under the Siberian Branch of the Russian Academy of Medical Sciences, Kemerovo, Russian - - 2014
The development of computer-based 3D models of the aortic root is one of the most important problems in constructing the prostheses for transcatheter aortic valve implantation. In the current study, we analyzed data from 117 patients with and without aortic valve disease and computed tomography data from 20 patients without ...
Liu Dong - - 2014
Aspheric non-null testing, as an alternative to the traditional null testing, achieves more flexible measurements. However, figure-error reconstruction in non-null tests has always been difficult due to the presence of retrace error. A novel method with reverse optimization is proposed for aspheric figure-error reconstruction in a non-null interferometer. It is ...
Cai Junfeng J Department of Cardiosurgery, Ruijin Hospital, Shanghai, - - 2014
 Geometric features of the aortic valve play an important role in many applications, such as the clinical diagnostics, shape modeling and image-guided cardiac interventions, especially for the transcatheter aortic valve implantation (TAVI) procedure. However, few works have been reported on the topic of aortic valve segmentation from transesophageal echocardiography (TEE) ...
Cheng Z Z Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, - - 2014
Aortic dissection is a life-threatening process in which the weakened wall develops a tear, causing separation of wall layers. The dissected layers separate the original true aortic lumen and a newly created false lumen. If untreated, the condition can be fatal. Flow rate in the false lumen is a key ...
Yang Ming M INRA, UMR1391 ISPA, F-33140 Villenave d'Ornon, France Bordeaux Sciences Agro, UMR 1391 ISPA, F-33170 Gradignan, - - 2014
Windstorms are the major natural hazard affecting European forests, causing tree damage and timber losses. Modelling tree anchorage mechanisms has progressed with advances in plant architectural modelling, but it is still limited in terms of estimation of anchorage strength. This paper aims to provide a new model for root anchorage, ...
Nanda Aditi A Department of Prosthodontics, Maulana Azad Institute of Dental Sciences, Mamc Campus, New Delhi, - - 2014
Decimated dentitions may require raising the vertical dimension in some conditions while performing a full mouth rehabilitation treatment. Increase in a vertical dimension should be diagnosed by reversible methods prior to performing any irreversible methods for a minimum time period. Reversible methods like splints and overlay dentures are often used ...
Biglino Giovanni G * These authors contributed equally to this - - 2014
Reliability of computational models for cardiovascular investigations strongly depends on their validation against physical data. This study aims to experimentally validate a computational model of complex congenital heart disease (i.e., surgically palliated hypoplastic left heart syndrome with aortic coarctation) thus demonstrating that hemodynamic information can be reliably extrapolated from the ...
Vismara Riccardo R 3 For Cardio Lab, Università di Milano - Politecnico di Milano, Milan - - - 2014
Cusp extension technique (CET) is a reparative surgical procedure for restoring aortic valve function by suturing patches to the compromised native leaflets. Its outcomes are strongly dependent on the ability of the surgeon. We proposed and tested a novel approach on an in vitro model, aimed at standardizing and simplifying ...
Andrinopoulou Eleni-Rosalina ER Department of Biostatistics, Erasmus MC, Rotterdam, The Netherlands; Department of Cardiothoracic Surgery, Erasmus MC, Rotterdam, The - - 2014
Aortic gradient and aortic regurgitation are echocardiographic markers of aortic valve function. Both are biomarkers repeatedly measured in patients with valve abnormalities, and thus, it is expected that they are biologically interrelated. Loss of follow-up could be caused by multiple reasons, including valve progression related, such as an intervention or ...
Capodanno Davide D Division of Cardiology, Ferrarotto Hospital, University of Catania, Catania, Italy; ETNA Foundation, Catania, Italy. Electronic address: - - 2014
Risk stratification tools used in patients with severe aortic stenosis have been mostly derived from surgical series. Although specific predictors of early mortality with transcatheter aortic valve replacement (TAVR) have been identified, the prognostic impact of their combination is unexplored. We sought to develop a simple score, using preprocedural variables, ...
Jassar Arminder S AS Gorman Cardiovascular Research Group, University of Pennsylvania, Glenolden, Pennsylvania; Department of Surgery, University of Pennsylvania, Philadelphia, - - 2014
Surgical techniques for aortic valve (AV) repair are directed toward restoring normal structural relationships in the aortic root and rely on detailed assessment of root and valve anatomy. Noninvasive three-dimensional (3D) imaging and modeling may assist in patient selection and operative planning. Transesophageal real-time 3D echocardiographic images of 5 patients ...
Rolls A E AE Division of Surgery and Cancer Imperial College London, London, UK - - - 2014
Endovascular intervention has revolutionized the treatment of aortic disease, extending the cohort of patients eligible for repair. Accurate planning for endovascular aortic repair is essential. Recent advances in modern software have demonstrated potential for improving outcomes and enhancing the decision making process beyond 3D measurements and intraoperative navigation techniques. With ...
Pal Siladitya S Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United - - 2014
Aortic dissection (AoD) is a common condition that often leads to life-threatening cardiovascular emergency. From a biomechanics viewpoint, AoD involves failure of load-bearing microstructural components of the aortic wall, mainly elastin and collagen fibers. Delamination strength of the aortic wall depends on the load-bearing capacity and local micro-architecture of these ...
Kamangar Sarfaraz S Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur, - - 2014
The present study deals with the functional severity of a coronary artery stenosis assessed by the fractional flow reserve (FFR). The effects of different geometrical shapes of lesion on the diagnostic parameters are unknown. In this study, 3D computational simulation of blood flow in three different geometrical shapes of stenosis ...
Veljković Dejan Ž DŽ Research and Development Center for Bioengineering BioIRC, Kragujevac, - - 2014
Most of hyperelastic models for the constitutive modeling of the typical mechanical behaviour of the arterial wall tissue in literature are based on the test data from different animals and arteries. This paper is concerned with the material parameter identification of several phenomenological hyperelastic models by fitting the data from ...
Chen Chia-Yuan - - 2013
The pathology of the human abdominal aortic aneurysm (AAA) and its relationship to the later complication of intraluminal thrombus (ILT) formation remains unclear. The hemodynamics in the diseased abdominal aorta is hypothesized to be a key contributor to the formation and growth of ILT. The objective of this investigation is ...
Casciaro Mariano E - - 2013
Diagnosis and management of thoracic aorta (TA) disease demand the assessment of accurate quantitative information of the aortic anatomy. We investigated the principal modes of variation in aortic 3-dimensional geometry paying particular attention to the curvilinear portion. Images were obtained from extended noncontrast multislice computed tomography scans, originally intended for ...
Alimohammadi Mona - - 2013
Aortic dissection has high morbidity and mortality rates and guidelines regarding surgical intervention are not clearly defined. The treatment of aortic dissection varies with each patient and detailed knowledge of haemodynamic and mechanical forces would be advantageous in the process of choosing a course of treatment. In this study, a ...
Bollache E - - 2013
The aorta plays a major role in the cardiovascular system and its function and structure are primarily affected by aging, eating habits, life style and other cardiovascular risk factors, inducing increased stiffness which is associated with cardiovascular and cerebral morbi-mortality. Our objective was to develop and validate a robust subject-specific ...
Patil Mukesh D - - 2013
Recently fractional-order (FO) differential equations are widely used in the areas of modeling and control. They are multivalued in nature hence their stability is defined using Riemann surfaces. The stability analysis of FO linear systems using the technique of Root Locus is the main focus of this paper. Procedure to ...
Fresiello Libera L Section of Rome, Institute of Clinical Physiology, National Research Council, Rome - Italy and Nale?cz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw - - - 2013
Introduction: The aim of this study was to investigate the effects of the intra aortic balloon pump (IABP) and of aortic compliance on left ventricular performance, including the effects of baroreflex control.
Methods: The study was conducted using a hybrid cardiovascular simulator, including a computational cardiovascular sub-model, a hydraulic sub-model of ...
Soslow Jonathan H - - 2013
Diagnosing coarctation of the aorta (CoA) in the presence of a patent ductus arteriosus (PDA) may require observation until PDA closure. The aim of this study was to create a model incorporating previously published indices to estimate the probability of neonatal CoA in the presence of a PDA. A retrospective "investigation" ...
Garcia Julio - - 2013
Valve effective orifice area EOA and transvalvular mean pressure gradient (MPG) are the most frequently used parameters to assess aortic stenosis (AS) severity. However, MPG measured by cardiovascular magnetic resonance (CMR) may differ from the one measured by transthoracic Doppler-echocardiography (TTE). The objectives of this study were: 1) to identify ...
Hahn Rebecca T - - 2013
Studies evaluating three-dimensional echocardiographic (3DE) annular sizing for balloon-expandable transcatheter aortic valve replacement (TAVR) are limited. In this study, a retrospective analysis of transesophageal echocardiographic images was performed to assess the feasibility of multiplanar measurements of annular dimensions by the novel off-label use of commercially available 3DE software and correlate ...
Sturla Francesco - - 2013
Numerical modeling can provide detailed and quantitative information on aortic root (AR) biomechanics, improving the understanding of AR complex pathophysiology and supporting the development of more effective clinical treatments. From this standpoint, fluid-structure interaction (FSI) models are currently the most exhaustive and potentially realistic computational tools. However, AR FSI modeling ...
Schlicht M S MS Vascular Mechanics Laboratory, Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, USA. Electronic address: - - 2013
This study was performed to determine the feasibility of measuring the elastic properties of the arterial wall in vivo. To prove this concept, elastic parameters were calculated from an aortic model of elastic behavior similar to a human aorta using computed tomography angiography (CTA) images. We first constructed an aortic ...
Dangi Siddharth - - 2013
Closed-loop decoder adaptation (CLDA) is an emerging paradigm for improving or maintaining the online performance of brain-machine interfaces (BMIs). Here, we present Likelihood Gradient Ascent (LGA), a novel CLDA algorithm for a Kalman filter (KF) decoder that uses stochastic, gradient-based corrections to update KF parameters during closed-loop BMI operation. LGA's ...
Wang Juan - - 2013
Rooted phylogenetic trees constructed from different datasets (e.g. from different genes) are often conflicting with one another, i.e. they cannot be integrated into a single phylogenetic tree. Phylogenetic networks have become an important tool in molecular evolution, and rooted phylogenetic networks are able to represent conflicting rooted phylogenetic trees. Hence, ...
Mortensen Kristian H - - 2013
BACKGROUND: Identification of the subset females with Turner syndrome (TS) who face especially high risk of aortic dissection is difficult, and more optimal risk assessment is pivotal in order to improve outcomes. This study aimed to provide comprehensive, dynamic mathematical models of aortic disease in Turner syndrome by use of ...
Doshi Krunal A KA Lecturer, Department of Dravyaguna, Institute of Ayurvedic Pharmaceutical Sciences, Jamnagar, Gujarat, - - 2013
In Ayurveda, the roots of Eranda (Ricinus communis Linn.) are used in the treatment Amavata (rheumatism), Sotha (inflammation), Katisula (backache), Udararoga (disease of abdomen), Jwara (fever), etc, Due to high demand, root of the cultivated variety is mainly used in place of wild. But, a comparative phytochemical profile of both ...
Zhao Tingting - - 2013
The policy gradient approach is a flexible and powerful reinforcement learning method particularly for problems with continuous actions such as robot control. A common challenge is how to reduce the variance of policy gradient estimates for reliable policy updates. In this letter, we combine the following three ideas and give ...
Rashedi Mohammad - - 2013
In this paper, we assess the validity of two alternative tube-load models for describing the relationship between central aortic and peripheral arterial blood pressure (BP) waveforms in humans. In particular, a single-tube (1-TL) model and a serially connected two-tube (2-TL) model, both terminated with a Windkessel load, are considered as ...
Roccabianca S - - 2013
There has been a growing awareness over the past decade that stiffening of the aorta, and its attendant effects on hemodynamics, is both an indicator and initiator of diverse cardiovascular, neurovascular, and renovascular diseases. Although different clinical metrics of arterial stiffness have been proposed and found useful in particular situations, ...
García-Herrera Claudio M - - 2013
This work presents the modelling and simulation of the mechanical behaviour of the human aortic arch under in vivo conditions with pressure levels within the normal and hypertension physiological range. The cases studied correspond to young and aged arteries without cardiovascular pathologies. First, the tissue of these two groups is characterised ...
Ehsani Sara - - 2013
Mandibular first molar is the most important tooth with complicated morphology. In finite element (FE) studies, investigators usually prefer to model anterior teeth with a simple and single straight root; it makes the results deviate from the actual case. The most complicated and time-consuming step in FE studies is modeling ...
Bodner Gernot - - 2013
Plant root systems have a key role in ecology and agronomy. In spite of fast increase in root studies, still there is no classification that allows distinguishing among distinctive characteristics within the diversity of rooting strategies. Our hypothesis is that a multivariate approach for "plant functional type" identification in ecology ...
Lai Jiangshan - - 2013
Precise estimation of root biomass is important for understanding carbon stocks and dynamics in forests. Traditionally, biomass estimates are based on allometric scaling relationships between stem diameter and coarse root biomass calculated using linear regression (LR) on log-transformed data. Recently, it has been suggested that nonlinear regression (NLR) is a ...
Venegas-Pino Daniel E DE Department of Biochemistry and Biomedical Sciences, McMaster - - 2013
Atherosclerosis is a disease of the large arteries and a major underlying cause of myocardial infarction and stroke. Several different mouse models have been developed to facilitate the study of the molecular and cellular pathophysiology of this disease. In this manuscript we describe specific techniques for the quantification and characterization ...
Guyot Alexis A King's College London, Division of Imaging Sciences, London, - - 2013
Overlay of preoperative images is increasingly being used to aid complex endovascular aortic repair and is obtained by rigid 2D-3D registration of 3D preoperative (CT) and 2D intraoperative (X-ray) data. However, for tortuous aortas large non-rigid deformations occur, thus a non-rigid registration must be performed to enable an accurate overlay. ...
Itu Lucian - - 2012
We propose a CFD-based approach for the non-invasive hemodynamic assessment of pre- and post-operative coarctation of aorta (CoA) patients. Under our approach, the pressure gradient across the coarctation is determined from computational modeling based on physiological principles, medical imaging data, and routine non-invasive clinical measurements. The main constituents of our ...
Hoshida Yujin - - 2012
Chronic fibrotic liver diseases such as viral hepatitis eventually develop liver cirrhosis, which causes occurrence of hepatocellular carcinoma (HCC). Given the limited therapeutic efficacy in advanced HCC, prevention of HCC development could be an effective strategy for improving patient prognosis. However, there is still no established therapy to meet the ...
Krsmanovic Dejan - - 2012
The objective of this study was to determine the orientation and magnitude of maximal displacement forces (DFs) in the thoracic aortic aneurysm endograft (TAA endograft) in three-dimensional (3D) space. Theoretical computer model representing the anatomically worst-case scenario with respect to DF magnitude was used to calculate the magnitude and orientation ...
Teschke Rolf - - 2012
The aim of this current opinion report is to discuss relevant issues of regulatory causality assessment methods related to initially suspected herb-induced liver injury (HILI). Herbal hepatotoxicity represents a major clinical, regulatory and public challenge since its diagnosis may be difficult to be established, requiring a sophisticated approach that includes ...
Gu Zhidong - - 2012
Mycophenolate Mofetil (MMF) is widely used in preventing acute rejection in liver transplantation. Only free MPA (fMPA) can exert the pharmacological effect. In this study, we aimed to develop the new model which could be best fit to predict the fMPA area under the plasma concentration-time curve (AUC) by limited ...
Howell Brett A - - 2012
Drug-induced liver injury (DILI) is not only a major concern for all patients requiring drug therapy, but also for the pharmaceutical industry. Many new in vitro assays and pre-clinical animal models are being developed to help screen compounds for the potential to cause DILI. This study demonstrates that mechanistic, mathematical ...
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