Coronary Stent Fracture: Clinical Evidence Vs. the Testing Paradigm
ConclusionsThe full scale of stent fracture is most likely under-reported and its assessment is dependent on detection time and detection resolution. Within the event of SF it is not necessarily consequential; further research is warranted to distinguish when the event negatively impacts the patient. (Source: Cardiovascular Engineering and Technology)
Source: Cardiovascular Engineering and Technology - October 19, 2018 Category: Cardiology Source Type: research

A New Method for Simulating Embolic Coils as Heterogeneous Porous Media
ConclusionsThese results indicate that the benefits of the porous medium assumption can be retained if a heterogeneous approach is applied. Implementation of the presented method led to a substantial reduction in the total number of mesh elements compared to the conventional method, and greater accuracy was enabled by considering heterogeneity compared to the homogenous approach. (Source: Cardiovascular Engineering and Technology)
Source: Cardiovascular Engineering and Technology - October 18, 2018 Category: Cardiology Source Type: research

Reversed Auxiliary Flow to Reduce Embolism Risk During TAVI: A Computational Simulation and Experimental Study
ConclusionsThe present study confirms that the integration ofin vitro experiments and in silico analyses allows designing and benchmarking novel solutions for cerebral embolic protection during TAVI such as the proposed embo-deviation technique based on an auxiliary retrograde flow from the right subclavian artery. (Source: Cardiovascular Engineering and Technology)
Source: Cardiovascular Engineering and Technology - October 16, 2018 Category: Cardiology Source Type: research

Cardiac Valve Bioreactor for Physiological Conditioning and Hydrodynamic Performance Assessment
ConclusionsWe have developed a single bioreactor system that allows for step-wise conditioning protocols to be developed for each unique TEHV design as well as allows for hydrodynamic performance assessment. (Source: Cardiovascular Engineering and Technology)
Source: Cardiovascular Engineering and Technology - October 11, 2018 Category: Cardiology Source Type: research

Effect of Varying Viscosity on Two-Fluid Model of Blood Flow through Constricted Blood Vessels: A Comparative Study
ConclusionsThe two-phase fluid model is more significant than the single-fluid model. Effect of viscosity parameter on various hemodynamical quantities has been obtained. It is also concluded that a rising viscosity parameter (varying nature of viscosity) significantly distinguishes the single and two-fluid models in terms of changes in blood flow resistance. The outcome of present study may leave a significant impact on analyzing blood flow through small blood vessels with constriction, where correct measurement of flow rate and flow resistance for medical treatment is very important. (Source: Cardiovascular Engineering and Technology)
Source: Cardiovascular Engineering and Technology - October 9, 2018 Category: Cardiology Source Type: research

Inter-Laboratory Characterization of the Velocity Field in the FDA Blood Pump Model Using Particle Image Velocimetry (PIV)
ConclusionsInter-laboratory experimental mean velocity data (and the corresponding variance) were obtained for the FDA pump model and are available for download athttps://nciphub.org/wiki/FDA_CFD. Experimental datasets from the inter-laboratory characterization of benchmark flow models, including the blood pump model presented herein and our previous nozzle model, can be used for validating future CFD studies and to collaboratively develop guidelines on best practices for verification, validation, uncertainty quantification, and credibility assessment of CFD simulations in the evaluation of medical devices (e.g. ASME V&...
Source: Cardiovascular Engineering and Technology - October 5, 2018 Category: Cardiology Source Type: research

Abdominal Aortic Aneurysm Volumetric Evaluation During Mid-term Follow-Up After Endovascular Sealing Using the Nellix ™ Device
AbstractObjectivesTo analyze the volumetric evolution of abdominal aortic aneurysms after endovascular sealing (EVAS) with the Nellix ™ device during follow-up.MethodsPatients who underwent elective EVAS in our institution in 2014 and 2015 were retrospectively reviewed. Preoperative, postoperative and 1-year scans were processed. A custom software was conceived to assess semi-automated measurements of the aneurysm sac and the endograft sizes including volume, maximum diameter, sectional area and perimeter. Thrombus volume, aneurysm length, mean distance between the stents inside the polymer-filled sacs and endograft ...
Source: Cardiovascular Engineering and Technology - October 4, 2018 Category: Cardiology Source Type: research

Uncertainty Quantification for Non-invasive Assessment of Pressure Drop Across a Coarctation of the Aorta Using CFD
ConclusionThe uncertainty of numerical pressure drop calculation introduced by uncertainties during image segmentation and measurement of volume flow rates was comparable to the uncertainty of pressure drop measurements using invasive catheterization. However, in some patients this uncertainty would have led to different treatment decision. Therefore, patient-specific uncertainty assessment might help to better understand the reliability of a numerically calculated biomarker as the pressure drop across an aortic coarctation. (Source: Cardiovascular Engineering and Technology)
Source: Cardiovascular Engineering and Technology - October 3, 2018 Category: Cardiology Source Type: research

In Vitro Validation of 4D Flow MRI for Local Pulse Wave Velocity Estimation
Conclusion4D Flow MRI is a feasible method for estimating local PWV in simplein vitro models and is a viable tool for clinical analysis. In addition, choice in transit-time algorithm depends on flow waveform shape and arterial region. This study strengthens the validity of 4D Flow MRI local PWV measurement in simple models. However, this technique requires validation in more complex models before it is usedin vivo. (Source: Cardiovascular Engineering and Technology)
Source: Cardiovascular Engineering and Technology - September 14, 2018 Category: Cardiology Source Type: research

Real-World Variability in the Prediction of Intracranial Aneurysm Wall Shear Stress: The 2015 International Aneurysm CFD Challenge
AbstractPurposeImage-based computational fluid dynamics (CFD) is widely used to predict intracranial aneurysm wall shear stress (WSS), particularly with the goal of improving rupture risk assessment. Nevertheless, concern has been expressed over the variability of predicted WSS and inconsistent associations with rupture. Previous challenges, and studies from individual groups, have focused on individual aspects of the image-based CFD pipeline. The aim of this Challenge was to quantify the total variability of the whole pipeline.Methods3D rotational angiography image volumes of five middle cerebral artery aneurysms were pro...
Source: Cardiovascular Engineering and Technology - September 10, 2018 Category: Cardiology Source Type: research

Multiple Aneurysms AnaTomy CHallenge 2018 (MATCH): Phase I: Segmentation
ConclusionsMATCH provides an overview of segmentation methodologies for IAs and highlights the variability of surface reconstruction. Further, the study emphasizes the need for careful processing of initial segmentation results for a realistic assessment of clinically relevant morphological parameters. (Source: Cardiovascular Engineering and Technology)
Source: Cardiovascular Engineering and Technology - September 6, 2018 Category: Cardiology Source Type: research

Parametric Imaging for the Assessment of Cardiac Motion: A Review
AbstractThe assessment of wall motion abnormalities such as hypokinesia or dyskinesia and the identification of their extent as well as their degree of severity allow an accurate evaluation of several ischemic heart diseases and an early diagnosis of heart failure. These dysfunctions are usually revealed by a drop of contraction indicating a regional hypokinesia or a total absence of the wall motion in case of akinesia. The discrimination between these contraction abnormalities plays also a significant role in the therapeutic decision through the differentiation between the infarcted zones, which have lost their contractil...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

Aiding the Detection of QRS Complex in ECG Signals by Detecting S Peaks Independently
AbstractIn this paper, a novel algorithm for the accurate detection of QRS complex by combining the independent detection of R and S peaks, using fusion algorithm is proposed. R peak detection has been extensively studied and is being used to detect the QRS complex. Whereas, S peaks, which is also part of QRS complex can be independently detected to aid the detection of QRS complex. In this paper, we suggest a method to first estimate S peak from raw ECG signal and then use them to aid the detection of QRS complex. The amplitude of S peak in ECG signal is relatively weak than corresponding R peak, which is traditionally us...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

Transcatheter Mitral Valve Replacement: Functional Requirements for Device Design, Bench-Top, and Pre-Clinical Evaluation
This article provides a review of the mitral valve disease as well as general considerations and guidance for developing a TMVR device based on International Industry Standards. Specific details pertaining to the mitral valve apparatus, morphology of mitral valve disease, assessment of specific patient population as well as hazard analysis to evaluate and develop a TMVR device to treat a specific patient population have been included. The details contained within this report are not all inclusive or explicate for every technology being developed but rather thought of as a general guide on how a TMVR technology could be dev...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

Fabrication and Testing of Electrospun Polyurethane Blended with Chitosan Nanoparticles for Vascular Graft Applications
In this study, a small vascular graft based on polyurethane (PU) blended with chitosan (Ch) nanoparticles was fabricated using electrospinning technique. Initially, the chitosan nanoparticles were synthesized using ionic gelation method. UV –Vis spectrophotometer confirmed the presence of synthesized Ch nanoparticles by exhibiting absorption peak at 288 nm and the Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the existence of the chitosan. Further, the synthesized Ch nanoparticles showed size diameter in the rang e of 134 ± 58 nm as measured using ImageJ. In the elec...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

The Mechanical Characterisation of Bovine Embolus Analogues Under Various Loading Conditions
AbstractEmbolus Analogues (EAs) can provide understanding of the mechanical characteristics of blood clots of cardiac origin. Bovine EAs (n = 29) were fabricated with varying concentrations of thrombin (0–20 NIHU/ml blood). Histological staining confirmed that EA composition compared sufficiently with human samples reported in literature. EAs were mechanically described under seven testing conditions: tensile, compression, shear wave ultrasound elastography (SWE), parallel plate rheometry, indentation, creep and relaxation. The Young modulus of bovine EAs in tension varied from 7 kPa (5% strain) to...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

Impact of Clinically Relevant Elliptical Deformations on the Damage Patterns of Sagging and Stretched Leaflets in a Bioprosthetic Heart Valve
AbstractAfter implantation of a transcatheter bioprosthetic heart valve its original circular circumference may become distorted, which can lead to changes in leaflet coaptation and leaflets that are stretched or sagging. This may lead to early structural deterioration of the valve as seen in some explanted transcatheter heart valves. Ourin vitro study evaluates the effect of leaflet deformations seen in elliptical configurations on the damage patterns of the leaflets, with circular valve deformation as the control. Bovine pericardial tissue heart valves were subjected to accelerated wear testing under both circular (N&thi...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

The Effect of Acute Pulmonary Hypertension on Tricuspid Annular Height, Strain, and Curvature in Sheep
AbstractThe tricuspid annulus shows significant alterations in patients with functional tricuspid regurgitation –tricuspid valve dysfunction that is secondary to other diseases such as pulmonary hypertension. Early changes in annular shape and dynamics may provide an understanding of disease mechanisms and could predict disease progression. To gain a mechanistic insight into these early changes we perform a spatially-resolved analysis of the effect of acute pulmonary hypertension on the tricuspid annulus in sheep. To this end, we suture sonomicrometry crystals to the annulus of nine sheep and record their locations i...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

Effect of Pneumatic Tubing System Transport on Platelet Apheresis Units
AbstractPlatelet apheresis units are transfused into patients to mitigate or prevent bleeding. In a hospital, platelet apheresis units are transported from the transfusion service to the healthcare teamsvia two methods: a pneumatic tubing system (PTS) or ambulatory transport. Whether PTS transport affects the activity and utility of platelet apheresis units is unclear. We quantified the gravitational forces and transport time associated with PTS and ambulatory transport within our hospital. Washed platelets and supernatants were prepared from platelet apheresis units prior to transport as well as following ambulatory or PT...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

Cardiogoniometry Compared to Fractional Flow Reserve at Identifying Physiologically Significant Coronary Stenosis: The CARDIOFLOW Study
AbstractCardiogoniometry (CGM) is method of 3-dimensional electrocardiographic assessment which has been shown to identify patients with angiographically defined, stable coronary artery disease (CAD). However, angiographic evidence of CAD, does not always correlate to physiologically significant disease. The aim of our study was to assess the ability of CGM to detect physiologically significant coronary stenosis defined by fractional flow reserve (FFR). In a tertiary cardiology centre, elective patients with single vessel CAD were enrolled into a prospective double blinded observational study. A baseline CGM recording was ...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

Efficient Computational Modeling of Human Ventricular Activation and Its Electrocardiographic Representation: A Sensitivity Study
AbstractPatient-specific models of the ventricular myocardium, combined with the computational power to run rapid simulations, are approaching the level where they could be used for personalized cardiovascular medicine. A major remaining challenge is determining model parameters from available patient data, especially for models of the Purkinje-myocardial junctions (PMJs): the sites of initial ventricular electrical activation. There are no non-invasive methods for localizing PMJs in patients, and the relationship between the standard clinical ECG and PMJ model parameters is underexplored. Thus, this study aimed to determi...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

Realistic Vascular Replicator for TAVR Procedures
We report on a novel benchtop patient-specific arterial replicator designed for testing TAVR and training interventional cardiologists in the procedure. The Replicator is an accurate model of the human upper body vasculature for training physicians in percutaneous interventions. It comprises of fully-automated Windkessel mechanism to recreate physiological flow conditions. Calcified aortic valve models were fabricated and incorporated into the Replicator, then tested for performing TAVR procedure by an experienced cardiologist using the Inovare valve. EOA, pressures, and angio grams were monitored pre- and post-TAVR. A St....
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

A Shape Memory Alloy-Based Miniaturized Actuator for Catheter Interventions
AbstractIn the current scenario of endovascular intervention, surgeons have to manually navigate the catheter within the complex vasculature of the human body under the guidance of X-ray. This manual intervention upsurges the possibilities of vessel damage due to frequent contact between the catheter and vasculature wall. In this context, a shape memory alloy-based miniaturized actuator was proposed in this study with a specific aim to reduce vessel wall related damage by improving the bending motions of the guidewire tip in a semi-automatic fashion. The miniaturized actuator was integrated with a FDA-approved guidewire an...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

Computational Fluid Dynamics Assessment Associated with Transcatheter Heart Valve Prostheses: A Position Paper of the ISO Working Group
AbstractThe governing international standard for the development of prosthetic heart valves is International Organization for Standardization (ISO) 5840. This standard requires the assessment of the thrombus potential of transcatheter heart valve substitutes using an integrated thrombus evaluation. Besides experimental flow field assessment andex vivo flow testing, computational fluid dynamics is a critical component of this integrated approach. This position paper is intended to provide and discuss best practices for the setup of a computational model, numerical solving, post-processing, data evaluation and reporting, as ...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

A Comparison of Five Algorithms for Fetal Magnetocardiography Signal Extraction
AbstractFetal magnetocardiography (fMCG) provides accurate and reliable measurements of electrophysiological events in the fetal heart and is capable of studying fetuses with congenital heart diseases. A variety of techniques exist to extract the fMCG signal with the demand for non-invasively obtained fetal cardiac information. To the best of our knowledge, there is no comparative study published in the field as to how the various extraction algorithms perform. We perform a comparative study of the ability of five methods to extract the fMCG using real biomagnetic signals, two of those methods are applied to real fMCG data...
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

Editorial
(Source: Cardiovascular Engineering and Technology)
Source: Cardiovascular Engineering and Technology - September 1, 2018 Category: Cardiology Source Type: research

Mechanical Characterization of the Lamellar Structure of Human Abdominal Aorta in the Development of Atherosclerosis: An Atomic Force Microscopy Study
AbstractAtherosclerosis is a major risk factor for cardiovascular disease. However, mechanisms of interaction of atherosclerotic plaque development and local stiffness of the lamellar structure of the arterial wall are not well established. In the current study, the local Young ’s modulus of the wall and plaque components were determined for three different groups of healthy, mildly diseased and advanced atherosclerotic human abdominal aortas. Histological staining was performed to highlight the atherosclerotic plaque components and lamellar structure of the aortic media , consisting of concentric layers of elastin a...
Source: Cardiovascular Engineering and Technology - July 13, 2018 Category: Cardiology Source Type: research

Transcatheter Mitral Valve Replacement: Functional Requirements for Device Design, Bench-Top, and Pre-Clinical Evaluation
This article provides a review of the mitral valve disease as well as general considerations and guidance for developing a TMVR device based on International Industry Standards. Specific details pertaining to the mitral valve apparatus, morphology of mitral valve disease, assessment of specific patient population as well as hazard analysis to evaluate and develop a TMVR device to treat a specific patient population have been included. The details contained within this report are not all inclusive or explicate for every technology being developed but rather thought of as a general guide on how a TMVR technology could be dev...
Source: Cardiovascular Engineering and Technology - June 27, 2018 Category: Cardiology Source Type: research

A Shape Memory Alloy-Based Miniaturized Actuator for Catheter Interventions
AbstractIn the current scenario of endovascular intervention, surgeons have to manually navigate the catheter within the complex vasculature of the human body under the guidance of X-ray. This manual intervention upsurges the possibilities of vessel damage due to frequent contact between the catheter and vasculature wall. In this context, a shape memory alloy-based miniaturized actuator was proposed in this study with a specific aim to reduce vessel wall related damage by improving the bending motions of the guidewire tip in a semi-automatic fashion. The miniaturized actuator was integrated with a FDA-approved guidewire an...
Source: Cardiovascular Engineering and Technology - June 26, 2018 Category: Cardiology Source Type: research

Impact of Clinically Relevant Elliptical Deformations on the Damage Patterns of Sagging and Stretched Leaflets in a Bioprosthetic Heart Valve
AbstractAfter implantation of a transcatheter bioprosthetic heart valve its original circular circumference may become distorted, which can lead to changes in leaflet coaptation and leaflets that are stretched or sagging. This may lead to early structural deterioration of the valve as seen in some explanted transcatheter heart valves. Ourin vitro study evaluates the effect of leaflet deformations seen in elliptical configurations on the damage patterns of the leaflets, with circular valve deformation as the control. Bovine pericardial tissue heart valves were subjected to accelerated wear testing under both circular (N&thi...
Source: Cardiovascular Engineering and Technology - June 12, 2018 Category: Cardiology Source Type: research

Development of an In Vitro Cardiac Ischemic Model Using Primary Human Cardiomyocytes
AbstractDeveloping experimental models to study ischemic heart disease is necessary for understanding of biological mechanisms to improve the therapeutic approaches for restoring cardiomyocytes function following injury. The aim of this study was to develop anin vitro hypoxic/re-oxygenation model of ischemia using primary human cardiomyocytes (HCM) and define subsequent cytotoxic effects. HCM were cultured in serum and glucose free medium in hypoxic condition with 1% O2 ranging from 30  min to 12 h. The optimal hypoxic exposure time was determined using Hypoxia Inducible Factor 1α (HIF-1α) as the hypo...
Source: Cardiovascular Engineering and Technology - June 11, 2018 Category: Cardiology Source Type: research

The Effect of Acute Pulmonary Hypertension on Tricuspid Annular Height, Strain, and Curvature in Sheep
AbstractThe tricuspid annulus shows significant alterations in patients with functional tricuspid regurgitation –tricuspid valve dysfunction that is secondary to other diseases such as pulmonary hypertension. Early changes in annular shape and dynamics may provide an understanding of disease mechanisms and could predict disease progression. To gain a mechanistic insight into these early changes we perform a spatially-resolved analysis of the effect of acute pulmonary hypertension on the tricuspid annulus in sheep. To this end, we suture sonomicrometry crystals to the annulus of nine sheep and record their locations i...
Source: Cardiovascular Engineering and Technology - June 1, 2018 Category: Cardiology Source Type: research

Correction to: Editorial: Special Issue on Heart Valve Mechanobiology
Original article has been updated to include names and affiliations of authors. (Source: Cardiovascular Engineering and Technology)
Source: Cardiovascular Engineering and Technology - May 24, 2018 Category: Cardiology Source Type: research

Effect of Pneumatic Tubing System Transport on Platelet Apheresis Units
AbstractPlatelet apheresis units are transfused into patients to mitigate or prevent bleeding. In a hospital, platelet apheresis units are transported from the transfusion service to the healthcare teamsvia two methods: a pneumatic tubing system (PTS) or ambulatory transport. Whether PTS transport affects the activity and utility of platelet apheresis units is unclear. We quantified the gravitational forces and transport time associated with PTS and ambulatory transport within our hospital. Washed platelets and supernatants were prepared from platelet apheresis units prior to transport as well as following ambulatory or PT...
Source: Cardiovascular Engineering and Technology - May 21, 2018 Category: Cardiology Source Type: research

Biomechanical Impact of Wrong Positioning of a Dedicated Stent for Coronary Bifurcations: A Virtual Bench Testing Study
In conclusion, the study shows that a ‘recommended’ Tryton stent positioning may be required for optimal clini cal results. (Source: Cardiovascular Engineering and Technology)
Source: Cardiovascular Engineering and Technology - May 17, 2018 Category: Cardiology Source Type: research

Parametric Imaging for the Assessment of Cardiac Motion: A Review
AbstractThe assessment of wall motion abnormalities such as hypokinesia or dyskinesia and the identification of their extent as well as their degree of severity allow an accurate evaluation of several ischemic heart diseases and an early diagnosis of heart failure. These dysfunctions are usually revealed by a drop of contraction indicating a regional hypokinesia or a total absence of the wall motion in case of akinesia. The discrimination between these contraction abnormalities plays also a significant role in the therapeutic decision through the differentiation between the infarcted zones, which have lost their contractil...
Source: Cardiovascular Engineering and Technology - May 14, 2018 Category: Cardiology Source Type: research

Editorial: Special Issue on Heart Valve Mechanobiology
(Source: Cardiovascular Engineering and Technology)
Source: Cardiovascular Engineering and Technology - May 14, 2018 Category: Cardiology Source Type: research

The Roles of Matrix Stiffness and ß-Catenin Signaling in Endothelial-to-Mesenchymal Transition of Aortic Valve Endothelial Cells
AbstractValve stiffening is a hallmark of aortic valve stenosis caused by excess extracellular matrix accumulation by myofibroblasts. We aimed to elucidate whether matrix stiffness regulates endothelial-to-mesenchymal transition (EndMT) of adult valvular endothelial cells (VECs) to myofibroblasts as a mechanism to further promote valve fibrosis. In addition, we specifically examined the role of the Wnt/ β-catenin signaling pathway in the development of myofibroblasts during EndMT, as Wnt/β-catenin signaling has been implicated in EndMT during heart development, is reactivated in valve disease, and is required for...
Source: Cardiovascular Engineering and Technology - May 14, 2018 Category: Cardiology Source Type: research

Modeling Right Ventricle Failure After Continuous Flow Left Ventricular Assist Device: A Biventricular Finite-Element and Lumped-Parameter Analysis
AbstractThe risk of right ventricle (RV) failure remains a major contraindication for continuous-flow left ventricular assist device (CF-LVAD) implantation in patients with heart failure. It is therefore critical to identify the patients who will benefit from early intervention to avoid adverse outcomes. We sought to advance the computational modeling description of the mechanisms underlying RV failure in LVAD-supported patients. RV failure was studied by computational modeling of hemodynamic and cardiac mechanics using lumped-parameter and biventricular finite element (FE) analysis. Findings were validated by comparison o...
Source: Cardiovascular Engineering and Technology - April 26, 2018 Category: Cardiology Source Type: research

Fabrication and Testing of Electrospun Polyurethane Blended with Chitosan Nanoparticles for Vascular Graft Applications
In this study, a small vascular graft based on polyurethane (PU) blended with chitosan (Ch) nanoparticles was fabricated using electrospinning technique. Initially, the chitosan nanoparticles were synthesized using ionic gelation method. UV –Vis spectrophotometer confirmed the presence of synthesized Ch nanoparticles by exhibiting absorption peak at 288 nm and the Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the existence of the chitosan. Further, the synthesized Ch nanoparticles showed size diameter in the rang e of 134 ± 58 nm as measured using ImageJ. In the elec...
Source: Cardiovascular Engineering and Technology - April 26, 2018 Category: Cardiology Source Type: research

Computational Fluid Dynamics Assessment Associated with Transcatheter Heart Valve Prostheses: A Position Paper of the ISO Working Group
AbstractThe governing international standard for the development of prosthetic heart valves is International Organization for Standardization (ISO) 5840. This standard requires the assessment of the thrombus potential of transcatheter heart valve substitutes using an integrated thrombus evaluation. Besides experimental flow field assessment andex vivo flow testing, computational fluid dynamics is a critical component of this integrated approach. This position paper is intended to provide and discuss best practices for the setup of a computational model, numerical solving, post-processing, data evaluation and reporting, as ...
Source: Cardiovascular Engineering and Technology - April 19, 2018 Category: Cardiology Source Type: research

Realistic Vascular Replicator for TAVR Procedures
We report on a novel benchtop patient-specific arterial replicator designed for testing TAVR and training interventional cardiologists in the procedure. The Replicator is an accurate model of the human upper body vasculature for training physicians in percutaneous interventions. It comprises of fully-automated Windkessel mechanism to recreate physiological flow conditions. Calcified aortic valve models were fabricated and incorporated into the Replicator, then tested for performing TAVR procedure by an experienced cardiologist using the Inovare valve. EOA, pressures, and angio grams were monitored pre- and post-TAVR. A St....
Source: Cardiovascular Engineering and Technology - April 13, 2018 Category: Cardiology Source Type: research

Cardiogoniometry Compared to Fractional Flow Reserve at Identifying Physiologically Significant Coronary Stenosis: The CARDIOFLOW Study
AbstractCardiogoniometry (CGM) is method of 3-dimensional electrocardiographic assessment which has been shown to identify patients with angiographically defined, stable coronary artery disease (CAD). However, angiographic evidence of CAD, does not always correlate to physiologically significant disease. The aim of our study was to assess the ability of CGM to detect physiologically significant coronary stenosis defined by fractional flow reserve (FFR). In a tertiary cardiology centre, elective patients with single vessel CAD were enrolled into a prospective double blinded observational study. A baseline CGM recording was ...
Source: Cardiovascular Engineering and Technology - April 12, 2018 Category: Cardiology Source Type: research

Aiding the Detection of QRS Complex in ECG Signals by Detecting S Peaks Independently
AbstractIn this paper, a novel algorithm for the accurate detection of QRS complex by combining the independent detection of R and S peaks, using fusion algorithm is proposed. R peak detection has been extensively studied and is being used to detect the QRS complex. Whereas, S peaks, which is also part of QRS complex can be independently detected to aid the detection of QRS complex. In this paper, we suggest a method to first estimate S peak from raw ECG signal and then use them to aid the detection of QRS complex. The amplitude of S peak in ECG signal is relatively weak than corresponding R peak, which is traditionally us...
Source: Cardiovascular Engineering and Technology - March 30, 2018 Category: Cardiology Source Type: research