A Novel Method for Optical High Spatiotemporal Strain Analysis for Transcatheter Aortic Valves In Vitro

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Simon Heide-Jørgensen ◽  
Sellaswasmy Kumaran Krishna ◽  
Jonas Taborsky ◽  
Tommy Bechsgaard ◽  
Rachid Zegdi ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Image Correlation ◽  
Deformation Analysis ◽  
Flow Loop ◽  
Transcatheter Aortic Valve ◽  
Wear And Tear ◽  
Valve Implantation

The transcatheter aortic valve implantation (TAVI) valve is a bioprosthetic valve within a metal stent frame. Like traditional surgical bioprosthetic valves, the TAVI valve leaflet tissue is expected to calcify and degrade over time. However, clinical studies of TAVI valve longevity are still limited. In order to indirectly assess the longevity of TAVI valves, an estimate of the mechanical wear and tear in terms of valvular deformation and strain of the leaflets under various conditions is warranted. The aim of this study was, therefore, to develop a platform for noncontact TAVI valve deformation analysis with both high temporal and spatial resolutions based on stereophotogrammetry and digital image correlation (DIC). A left-heart pulsatile in vitro flow loop system for mounting of TAVI valves was designed. The system enabled high-resolution imaging of all three TAVI valve leaflets simultaneously for up to 2000 frames per second through two high-speed cameras allowing three-dimensional analyses. A coating technique for applying a stochastic pattern on the leaflets of the TAVI valve was developed. The technique allowed a pattern recognition software to apply frame-by-frame cross correlation based deformation measurements from which the leaflet motions and the strain fields were derived. The spatiotemporal development of a very detailed strain field was obtained with a 0.5 ms time resolution and a spatial resolution of 72 μm/pixel. Hence, a platform offering a new and enhanced supplementary experimental evaluation of tissue valves during various conditions in vitro is presented.

scholarly journals Moderated Posters: Deformation imagingP96How accurate can different strain analysis tools detect regional function?abnormalities, a report from the second inter-vendor comparison?studyP97Variability and reproducibility of segmental longitudinal strain measurements, a report form the second intervendor comparison studyP98Systolic and diastolic left atrial deformation parameters before and after optimization of dual chamber pacemaker parametersP99The timing of the post systolic shortening in prediction of scarred myocardiumP100Altered contribution of longitudinal and radial motion to right ventricular ejection and filling in heart transplant recipientsP101Left ventricular and atrial function in old patients underwent transcatheter aortic valve implantation, evaluated by two and three-dimensional speckle tracking at eighteen-month follow-upP102Age-related changes in left ventricular strain measured by speckle-tracking echocardiography and association with telomere length in healthy peopleP103Intracardiac speckle tracking echocardiography-based method for assessment of pulmonary vein isolation in patients with atrial fibrillation

2016 ◽  
Vol 17 (suppl 2) ◽  
pp. ii9-ii11
Author(s):  
O. Mirea ◽  
O. Mirea ◽  
A. Karuzas ◽  
E. Nestaas ◽  
BK. Lakatos ◽  
...  
Keyword(s):  
Speckle Tracking ◽  
Speckle Tracking Echocardiography ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Left Ventricular ◽  
Old Patients ◽  
Left Ventricular Strain ◽  
Transcatheter Aortic Valve ◽  
Before And After ◽  
Valve Implantation

scholarly journals Intracardiac Visualization of Transcatheter Aortic Valve and Valve-in-Valve Implantation in an In Vitro Passive Beating Heart

2013 ◽  
Vol 6 (1) ◽  
pp. 92-93 ◽  
Author(s):  
Alberto M. Leopaldi ◽  
Riccardo Vismara ◽  
Guido Gelpi ◽  
Claudia Romagnoni ◽  
Gianfranco B. Fiore ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Beating Heart ◽  
Transcatheter Aortic Valve ◽  
Valve In Valve ◽  
Valve Implantation

Experimental Characterization and Finite Element Modeling of Film Capacitors for Automotive Applications

2016 ◽  
Author(s):  
D. Croccolo ◽  
T. M. Brugo ◽  
M. De Agostinis ◽  
S. Fini ◽  
G. Olmi
Keyword(s):  
Finite Element ◽  
Mechanical Response ◽  
High Reliability ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Life Time ◽  
Element Model ◽  
Image Correlation ◽  
Thermal Loads ◽  
Mechanical Shock

As electronics keeps on its trend towards miniaturization, increased functionality and connectivity, the need for improved reliability capacitors is growing rapidly in several industrial compartments, such as automotive, medical, aerospace and military. Particularly, recent developments of the automotive compartment, mostly due to changes in standards and regulations, are challenging the capabilities of capacitors in general, and especially film capacitors. Among the required features for a modern capacitor are the following: (i) high reliability under mechanical shock, (ii) wide working temperature range, (iii) high insulation resistance, (iv) small dimensions, (v) long expected life time and (vi) high peak withstanding voltage. This work aims at analyzing the key features that characterize the mechanical response of the capacitor towards temperature changes. Firstly, all the key components of the capacitor have been characterized, in terms of strength and stiffness, as a function of temperature. These objectives have been accomplished by means of several strain analysis methods, such as strain gauges, digital image correlation (DIC) or dynamic mechanical analysis (DMA). All the materials used to manufacture the capacitor, have been characterized, at least, with respect to their Young’s modulus and Poisson’s ratio. Then, a three-dimensional finite element model of the whole capacitor has been set up using the ANSYS code. Based on all the previously collected rehological data, the numerical model allowed to simulate the response in terms of stress and strain of each of the capacitor components when a steady state thermal load is applied. Due to noticeable differences between the thermal expansion coefficients of the capacitor components, stresses and strains build up, especially at the interface between different components, when thermal loads are applied to the assembly. Therefore, the final aim of these numerical analyses is to allow the design engineer to define structural optimization strategies, aimed at reducing the mechanical stresses on the capacitor components when thermal loads are applied.

Dynamic Analysis of Thin Glass Under Ball Drop Impact With New Metrics

2013 ◽  
Author(s):  
Liang Xue ◽  
Claire R. Coble ◽  
Hohyung Lee ◽  
Da Yu ◽  
Satish Chaparala ◽  
...  
Keyword(s):  
High Speed ◽  
Impact Testing ◽  
Image Correlation ◽  
Thin Glass ◽  
Fea Model ◽  
Wear And Tear ◽  
Local Measurements ◽  
Drop Impacts ◽  
Global And Local ◽  
The Impact

Response of brittle plate to impact loads has been the subject of many research studies [1–7]. Specifically, glass presents a wide variety of applications in daily life, and helps to protect the displays of smartphones, tablets, PCs, and TVs from everyday wear and tear. Therefore, the necessity of glass to resist scratches, drop impacts, and bumps from everyday use leads to the importance of investigation of the glass response under dynamic impact loading. The ball drop test has been applied in the past, specifying an energy threshold as a prediction metric. Use of energy as the key parameter in impact testing is limited, since it does not account for the time spent in contact during the impact event. This study attempts to establish a reliable metric for impact testing based on a momentum change threshold. The deformation and the strain of the glass will be obtained by the Digital Image Correlation (DIC) system, while the rebound velocity will be measured with the high speed cameras. The global and local measurements are conducted to verify the accuracy of the experimental results. Finally, the FEA model is developed using ANSYS/LS-DYNA to provide a comprehensive understanding of the dynamic response of the glass. Excellent correlation in deflection is obtained between the measurements and predictions.

scholarly journals 3D printed patient-specific aortic root models with internal sensors for minimally invasive applications

2020 ◽  
Vol 6 (35) ◽  
pp. eabb4641 ◽  
Author(s):  
Ghazaleh Haghiashtiani ◽  
Kaiyan Qiu ◽  
Jorge D. Zhingre Sanchez ◽  
Zachary J. Fuenning ◽  
Priya Nair ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Aortic Root ◽  
Three Dimensional ◽  
Sensor Arrays ◽  
Invasive Procedure ◽  
Patient Specific ◽  
Anatomical Site ◽  
Transcatheter Aortic Valve ◽  
Critical Regions

Minimally invasive surgeries have numerous advantages, yet complications may arise from limited knowledge about the anatomical site targeted for the delivery of therapy. Transcatheter aortic valve replacement (TAVR) is a minimally invasive procedure for treating aortic stenosis. Here, we demonstrate multimaterial three-dimensional printing of patient-specific soft aortic root models with internally integrated electronic sensor arrays that can augment testing for TAVR preprocedural planning. We evaluated the efficacies of the models by comparing their geometric fidelities with postoperative data from patients, as well as their in vitro hemodynamic performances in cases with and without leaflet calcifications. Furthermore, we demonstrated that internal sensor arrays can facilitate the optimization of bioprosthetic valve selections and in vitro placements via mapping of the pressures applied on the critical regions of the aortic anatomies. These models may pave exciting avenues for mitigating the risks of postoperative complications and facilitating the development of next-generation medical devices.

scholarly journals An in vitro evaluation of turbulence after transcatheter aortic valve implantation

2018 ◽  
Vol 156 (5) ◽  
pp. 1837-1848 ◽  
Author(s):  
Hoda Hatoum ◽  
Atieh Yousefi ◽  
Scott Lilly ◽  
Pablo Maureira ◽  
Juan Crestanello ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Transcatheter Aortic Valve Implantation ◽  
In Vitro Evaluation ◽  
Transcatheter Aortic Valve ◽  
Aortic Valve Implantation ◽  
Valve Implantation
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