3D Computer Research Articles

Modelling of annual sunlight availability on vertical shelves: A case study in Thailand

Limited cultivation areas in major cities have led to the possibility of vertical farming (the practice of growing crops in vertically stacked layers). However, one of the drawbacks of vertical farming is the limited availability of solar energy at the lower shelves. This study presents a model for predicting the annual sunlight availability on vertical shelves. The model uses the shelf’s structure, orientation, hourly solar radiation, and sunshine duration as inputs to Rhinoceros 3D or RHINO (a 3D computer graphics and computer-aided design application software with the Grasshopper plug-in). The calculated solar energy available at each level of the shelves from RHINO was converted to photosynthetic photon flux density (PPFD) and daily light integral (DLI) using spreadsheet software. This study investigated a vertical farm, in Chiang Mai, Thailand, with six parallel shelves at 1-meter spacing. Each shelf contained three levels with a spacing of 0.5 meters. Both north–south and east–west orientations were investigated. The model could predict PPFD and DLI at every level on the considered shelves. The north–south orientation provided uniform PPFD and DLI throughout the year. The top level of the shelves experiences the highest PPFD (1,949.86μmol*m-2*s-1) and DLI (36.80 mol*m-2*day-1). The PPFD and DLI values at the middle and bottom level were approximately 60% and 50% of the values at the top level, respectively. This information can be used for cultivation planning when considering vertical farming in urban areas. This study provides a sustainable means for future food production.

Object verification based on deep learning point feature comparison for scan-to-BIM

Building information models (BIMs) have been widely adopted in current construction projects to enhance the efficiency of facility maintenance operations. As-built BIMs can reflect the actual conditions of facilities and thus as-built BIM reconstruction has shown great significance in digital twin generation, building health monitoring, facility management and urban renewal. Laser scanners are capable to capture dense 3D measurements of the environment in a fast and highly accurate way. Therefore, laser scanning data have been widely used for as-built BIM generation. Although research efforts have been made on how to automatically achieve “Scan-to-BIM”, there are still gaps from applying current solutions to real scenarios. One of the challenges is that some irrelevant point clusters may be wrongly recognized as the desired object in the detection stage. This study presents a novel object verification approach based on deep learning point feature comparison to improve the accuracy of automated BIM reconstruction process. Firstly, a KPConv-based deep neural network is developed and trained to perform 3D point feature computation. Then through comparing point features calculated for extracted point clusters and as-designed BIM generated point clouds, point feature distance maps are generated. Afterwards, to automatically analyze the generated feature distance maps, a dataset including simulated positive and negative instances is created based on ModelNet40. And a tiny neural network is established and trained on the prepared dataset to acquire ability of distinguishment. To validate the feasibility of the proposed technique, experiments were conducted on both artificial point clouds and real scan data collected in one MEP room in a water treatment work in Hong Kong. It is demonstrated that the proposed technique can successfully filter out all the false positives in the Scan-to-BIM process, improving reconstruction accuracy significantly.

Individual computer-assisted 3D planning for placement of auricular prosthesis anchors in combination with an implantable transcutaneous bone conduction hearing device in patients with aural atresia. German version

The simultaneous implantation of the Bonebridge (MED-EL, Innsbruck, Austria), asemi-implantable active transcutaneous bone conduction hearing device and anchors for auricular prostheses can be challenging as both implants contain magnets and compete for the narrow space in the designated implantation area. Apreoperative planning tool (virtual surgery) was used with individual 3D computer models of the skull and implants for finding optimal implant positions for both the floating mass transducer (FMT) and the anchors for the auricular prosthesis. The interaction between the magnetic prosthesis anchors and the FMT was measured by means of static magnetic forces. A retrospective data analysis was conducted to evaluate the surgical and audiological outcome. Between 2014 and 2021 a3D planning of a simultaneous implantation of the Bonebridge with auricular prosthesis anchors was conducted on 6 ears of 5 patients (3males, 2females; age range 17-56years). The individual preoperative planning was considered very useful for the optimal placement of bone anchors in combination with the Bonebridge. Audiological data showed aclear benefit for hearing 3months and > 11months after implantation. No adverse interactions between the magnetic prosthesis anchors and the FMT were observed. In two patients, revision surgery was carried out due to skin inflammation or wound healing problems. No long-term complications were observed 3-5 years after surgery. Preoperative 3D planning represents a clear benefit for the simultaneous audiological and esthetic rehabilitation using the Bonebridge and anchors for auricular prostheses.

Numerical Analysis of an Electromagnetic Stirring System for Composite Plastic Materials with Ferromagnetic Particles

AbstractThis paper deals with a Finite Element (FE) numerical analysis of an electromagnetic stirring system for composite plastic materials with ferromagnetic particles. The electromagnetic stirring process is ensured by the magnetic forces acting on the ferromagnetic particles spread in the plastic matrix. These forces are produced by the rotating magnetic field of the stator of a three‐phase induction motor supplied from an inverter. The analysis is carried out using the professional software package Flux for electromagnetic field computation based on the FE method. The 2D computations allowed to estimate the magnetic forces and their orientation acting on micrometric particles spread in a fluid plastic material. A preliminary experimental setup is also built for studying the proposed solution.

The bearing capacity of arch cover structures made of thin-walled cold-formed profiles

Introduction. The article is focused on evaluating the stress-strain state of nonreinforced arch cover structures made of thin-walled cold-formed profiles and arch cover structures reinforced by arch frames made of triangular trusses and girders. The relevance of the study is backed by the need to reinforce arch covers in the event that the design area of operation of a structure is different from the actual area of operation, which is confirmed by the recent cases of collapse of these structures. To reduce the labour input into simulation, the authors suggest a 3D modelling methodology presented using the case of a hangar reinforced by orthotropic plates and rods.
 Materials and methods. A 2D analysis of an arch was performed using the parameters of the reduced cross-section and a 3D analysis of the same arch was performed using a combined cross-section of plates and rods to verify the methodology. The 2D arch and 3D models were subjected to snow loading in compliance with the regulatory document document SP 20.13330.2016 “Loads and impacts”. Parameters of reduced straight sections and stresses, arising in the 2D arch, were analyzed on the basis of identified internal forces and the regulatory document SP 260.1325800.2016 “Thin-walled steel structures made of cold-formed galvanized profiles and corrugated sheets”. A reduction in the rigidity of corrugated sections is taken into account by assessing the rigidity subjected to the effect of a single force. Finite element modeling was conducted in SCAD Office software; stresses and displacements were calculated automatically.
 Results. The 3D calculation method involving orthotropic plates and rods showed satisfactory convergence with the calculation made in the two-dimensional formulation. Maximum stresses arising in a 3D model are 2 % lower than in a 2D arch, and maximum displacements are 21 % lower thanks to a more accurate FEM analysis of the 3D behaviour of the whole hangar.
 Conclusions. The proposed modeling technique reduces the labor intensity of structural modeling and is suitable for evaluating the joint behaviour of basic and reinforced structures of any type.

3D bioprinting in airway reconstructive surgery: A pilot study

ObjectivesOpen surgery is a reliable choice for congenital subglottic stenosis, that represents the third most common congenital anomaly of the larynx. One of the procedures performed is anterior laryngotracheal reconstruction (LTR) with anterior rib graft. The objective of this preliminary study was to evaluate the potential of 3D printing technology for the realization of laryngo-tracheal scaffold in Polycaprolactone (PCL) implanted in vivo in ovine animal model. MethodsA 3D computer model of a laryngeal graft and a tracheal graft was designed and printed with PCL through 3D additive manufacturing technology. The scaffolds were seeded with autologous mesenchymal stem cells and cultured in vitro for up to 14 days. Anterior graft LTR with 3D printed scaffolds was performed on 5 sheep. The animals underwent endoscopic examinations at the first, 3rd, 6th, and 12th weeks after surgery and before sacrifice. The integration of the material was evaluated by the pathologist. ResultsTwo animals showed a favourable postoperative course and were sacrificed at 6 months postoperatively. In these cases, we observed endoscopically a complete integration of the cellularized PCL scaffold into the peri-implant tissues, and the pathologist found the growth of respiratory epithelium on the scaffold's inner surface. Other two animals showed a difficult post-operative recovery characterized by respiratory distress resulting in early sacrifice on postoperative days 31 and 33. In these animals we found a poor integration of the grafts into the tracheal structure, and a better integration of the laryngeal scaffold. The last animal developed a wound abscess and was sacrificed 80 days after surgery. We observed, in this case, a poor scaffold integration and an acute inflammatory reaction. ConclusionsFrom the preliminary data obtained we found that the excessive stiffness of the material, along with the anatomical features of the sheep, is a major limitation of this study. It will be necessary in the future to create a new biocompatible, more flexible and elastic graft, to achieve greater integration into surrounding tissues. Bioconstructed grafts could simplify surgery for the treatment of laryngo-tracheal stenosis, particularly in the treatment of long tracheal stenoses, which have, at the moment, very complex surgical options. Level of evidenceNA.

A Novel Low-Cost Three-Dimensional Printed Brace Design Method for Early Onset Scoliosis

Abstract Early onset scoliosis (EOS) is a type of spine deformity that presents before 10 years of age. The biomechanical properties in scoliosis have been found to be different, especially in the case of the concave and convex paravertebral muscles. Based on this fact, a novel three-dimensional (3D) printed patient-specific asymmetric stiffness brace design method is proposed in this paper, aiming to provide asymmetric stiffness to match “imbalanced” biomechanical properties of the concave and convex paravertebral muscles, respectively, and treat EOS by applying the block-structure brace. A 3D computer aided design draft model of the brace contour was implemented from 3D scanning. The asymmetric stiffness block-structure brace was designed in Rhinoceros and the finite element (FE) model was imported into abaqus. FE simulation was employed to study the mechanical characteristics of the brace, which provided a quantitative index for the imbalanced property of brace stiffness. The results of the FE simulation showed that the stiffnesses of the concave and convex sides were 145.88 N/mm and 35.95 N/mm, respectively. The block-structure brace was fabricated using 3D printing. Asymmetric stiffness was evaluated by corrective force measurements, which were obtained from a thin-film pressure sensor equipped on the brace. The patient-specific asymmetric stiffness brace was applied to clinical practice in a one-year-old EOS patient. A novel low-cost 3D printed brace design method for EOS was proposed in this study that could potentially be useful in patient treatment acceptance.

The Effects of Problem-Based Serious Games on Learning 3D Computer Graphics

The Effects of Problem-Based Serious Games on Learning 3D Computer Graphics

Computer simulation of microwave cooking of sweet potato

AbstractAlthough sweet potatoes have the characteristic of becoming sweeter when heated, the MW treatment is challenging because its characteristic high heating rate can affect the intrinsic chemical changes of sweet potatoes during MW heating. To clarify this phenomena, experimental and simulated approaches for the microwave (MW) cooking of sweet potatoes were evaluated. The dielectric properties (DPs) of sweet potatoes during MW heating were measured from 20 to 90°C at 2450 MHz. A three‐dimensional (3D) geometric model based on the actual structure and size of the MW flatbed oven and sample was constructed. Two commercial software packages, which are based on the finite element method (FEM) were used for the calculation by coupling the analysis of electromagnetic fields and heat transfer. To improve the calculation during temperature simulation, a mathematical approach considering a contact layer for the boundary between the sample and the ceramic plate was evaluated.The dielectric constant decreased with increasing temperature; whereas, the dielectric loss factor values were similar at 20–60°C. However, at 60–90°C, the values decreased sharply. The temperature change inside the sweet potato was estimated using the 3D model and temperature profiles and cross‐section distributions were compared with the experimental results. The simulated results agree well to the measured results especially for the approach considering a contact layer for the surrounding air below the samples. These results are of potential value for the design of MW cooking systems for sweet potatoes.Practical ApplicationsThe applications of the findings of this study include but are not limited to: (a) use the measured DPs of sweet potatoes in both industrial applications and academia for developing novel applications of microwaveable sweet potato‐based products, (b) predict the temperature profiles and distributions of sweet potatoes using the developed 3D computer simulation model for MW heating in flatbed ovens, and (c) improve the simulation of MW heating of foods directly placed on the ceramic plate during MW treatment considering the contact layer approach evaluated in this study.

Virtual field trips utilizing virtual outcrop: construction, delivery and implications for the future

Abstract. The advent of photorealistic, 3D computer models of cliff sections (virtual outcrops) has improved the immersive nature of virtual geological field trips. As the COVID-19 pandemic led to widespread national and international travel restrictions, virtual field trips (VFTs) became practical and essential substitutes for traditional field trips and accelerated the development of VFTs based on virtual outcrop data. This contribution explores two such VFTs delivered to a masters level Integrated Petroleum Geoscience course at the University of Aberdeen. These VFTs are based on traditional field trips that are normally run to the Spanish Pyrenees and Utah (USA). The paper summarizes the delivery mechanism for VFTs based on virtual outcrops and examines student perception, gauged primarily through questionnaires and learning outcomes. The VFTs were run in LIME, a software specifically designed for the interpretation of 3D models and the delivery of VFTs. Overall, the student perception was very positive and comparable to satisfaction with the conventional trips. Staff feedback and student assessments suggest that the learning outcomes were satisfied and highlight the value of this method of teaching for students who are unable to attend the field trip and as an addition for those who can.

BETHSY 9.1b test calculation with TRACE using 3D vessel component

Recently, several advanced multidimensional computational tools for simulating reactor system behavior during real and hypothetical transient scenarios were developed. One of such advanced, best-estimate reactor systems codes is TRAC/RELAP Advanced Computational Engine (TRACE), developed by the U.S. Nuclear Regulatory Commission. The advanced TRACE comes with a graphical user interface called SNAP (Symbolic Nuclear Analysis Package). It is intended for pre- and post-processing, running codes, RELAP5 to TRACE input deck conversion, input deck database generation etc. The TRACE code is still not fully development and it will have all the capabilities of RELAP5. The purpose of the present study was therefore to assess the 3D capability of the TRACE on BETHSY 9.1b test. The TRACE input deck was semi-converted (using SNAP and manual corrections) from the RELAP5 input deck. The 3D fluid dynamics within reactor vessel was modeled and compared to 1D fluid dynamics. The TRACE 3D calculation was compared both to TRACE 1D calculation and RELAP5 calculation. Namely, the geometry used in TRACE is basically the same, what gives very good basis for the comparison of the codes. The only exception is 3D reactor vessel model in case of TRACE 3D calculation. The TRACE V5.0 Patch 1 and RELAP5/MOD3.3 Patch 4 were used for calculations. The BETHSY 9.1b test (International Standard Problem no. 27 or ISP-27) was 5.08 cm equivalent diameter cold leg break without high pressure safety injection and with delayed ultimate procedure. BETHSY facility was a 3-loop replica of a 900 MWe FRAMATOME pressurized water reactor. In general, all presented code calculations were in good agreement with the BETHSY 9.1b test. The TRACE 1D calculation results are comparable to RELAP5 calculated results. For some parameters they are better, this is mostly due to better tuning of the break flow, what influences timing of the transient. When comparing TRACE 1D and TRACE 3D calculation, the latter is slightly better. One reason for comparable results is already good agreement of 1D calculations and there was not much space to further improve the results. The other reason may be that in the facility the phenomena were mostly one dimensional (for example, external downcomer was used for reactor vessel modeling). However, when 3D behavior of the heater rod temperatures was investigated, the advantage of three dimensional treatment was clearly demonstrated.

Deployment of a deep-learning based multi-view stereo approach for measurement of ship shell plates

In this work, a measurement system integrated with a deep-learning based multi-view stereo (MVS) approach is developed to measure ship shell plates. Specifically, a deep learning architecture of CasMVSNet is deployed for depth map inference from multi-view images, which can remarkably decrease the dense reconstruction time and GPU memory consumption. This is the first report that a learned MVS architecture is deployed to three-dimensional (3D) reconstruction of ship shell plates. Measurement experiments are then performed for three typical hull plates to evaluate the accuracy, efficiency and completeness of the proposed measurement method. The results suggest that the complete point cloud data of the curved hull plates can be reconstructed in about 3 min with the average of errors less than 1 mm, which fulfills the requirements of precision and efficiency in shipbuilding production. Compared with traditional wooden templates, the proposed measurement method is more accurate, efficient and inexpensive. The developed measurement system with quantitative data can also be readily integrated with the 3D computer numerical control (CNC) plate bending machine. Moreover, the robustness and flexibility of the proposed measurement method have been verified by comparison with the measurement method based on active binocular stereovision.

RoseSegNet: An attention-based deep learning architecture for organ segmentation of plants

An important component for the advancement of plant breeding, genetics, and genomics research is the rapid and accurate measurement of phenotypic traits of large plant populations. The phenotypic data that are of interest can be at multiple levels of plant organization including organ-level geometric characteristics as well as the spatial organization of the organs. 3D computer vision enabling 3D geometry acquisition and processing promises to supply fast, automated phenotypic data collection. One important component of the processing pipeline is the segmentation of the plant into its structural components, such as leaves, stems, and flowers. In this paper, a novel 3D point-based deep learning network, namely RoseSegnet, is proposed for segmentation of point clouds of rosebush plants to their organs. The network is equipped with two attention-based modules, one for extracting contextual features at the encoder phase, another for feature propagation at the decoder phase. The network processes regions of points in a hierarchical manner, where at each level, point features are aggregated using attention-based operators. The aggregation is performed by incorporating point relations both within and between the receptive fields, defined by the hierarchical organization of points. RoseSegNet outperforms the widely-used architecture PointNet++ by 4% in terms of MIoU on the publicly available ROSE-X data set. Also, it is demonstrated that introducing local surface features together with the spatial coordinates of each 3D point at the input level boosts the segmentation performance of both networks by 9% in terms of MIoU . • A new 3D point-based deep learning architecture for organ segmentation of plants. • Attention-based modules for aggregation and propagation of features. • Exploiting point interactions within and between regions at multiple scales. • Incorporation of local surface features to the deep learning framework.

Non-Intrusive Fish Weight Estimation in Turbid Water Using Deep Learning and Regression Models.

Underwater fish monitoring is the one of the most challenging problems for efficiently feeding and harvesting fish, while still being environmentally friendly. The proposed 2D computer vision method is aimed at non-intrusively estimating the weight of Tilapia fish in turbid water environments. Additionally, the proposed method avoids the issue of using high-cost stereo cameras and instead uses only a low-cost video camera to observe the underwater life through a single channel recording. An in-house curated Tilapia-image dataset and Tilapia-file dataset with various ages of Tilapia are used. The proposed method consists of a Tilapia detection step and Tilapia weight-estimation step. A Mask Recurrent-Convolutional Neural Network model is first trained for detecting and extracting the image dimensions (i.e., in terms of image pixels) of the fish. Secondly, is the Tilapia weight-estimation step, wherein the proposed method estimates the depth of the fish in the tanks and then converts the Tilapia’s extracted image dimensions from pixels to centimeters. Subsequently, the Tilapia’s weight is estimated by a trained model based on regression learning. Linear regression, random forest regression, and support vector regression have been developed to determine the best models for weight estimation. The achieved experimental results have demonstrated that the proposed method yields a Mean Absolute Error of 42.54 g, R2 of 0.70, and an average weight error of 30.30 (±23.09) grams in a turbid water environment, respectively, which show the practicality of the proposed framework.

Calibration method of azimuth electromagnetic boundary detection logging while drilling based on air–seawater double-layer dielectric as reflection interface

Abstract An azimuth electromagnetic propagation logging while drilling tool provides the electrical parameters around a well in the intelligent drilling guidance system. It is a key link in intelligent guidance technology. As the stratum directivity parameter, the azimuth signal is associated with the compensation measurement of the resistivity instrument, which guides the drilling. However, it must be calibrated to have physical significance. The traditional method uses a water tank for calibration. However, this method is affected by the edge effect, which greatly weakens the azimuth signal. The model is complex and difficult to recover, which seriously suppresses the calibration results and causes errors in the azimuth signal. To eliminate the edge effect and simplify the model to improve the signal quality, an instrument calibration method based on sea level as the reflection interface is proposed in this paper. The air–seawater structure can simplify the calculation model, eliminate the edge effect and improve the signal strength. According to 1D air–seawater model simulation and 3D water tank model calculation, the feasibility of the simplified model is analyzed. According to the azimuth signal characteristics of the simplified model, an azimuth signal correction process that is more suitable for azimuth electromagnetic propagation logging while drilling is proposed. The measured data show that the air–seawater model improves the signal-to-noise ratio of the azimuth signal, verifies the detection ability of the azimuth antenna and provides technical support for oil and gas development in complex reservoirs.

Calculation of Aortic VAlve and LVOT Areas by a Modified Continuity Equation Using Different Echocardiography Methods: The CAVALIER Study.

Background: The area of the left ventricular outflow tract (ALVOT) represents a major component of the continuity equation (CE), which is, i.a., crucial to calculate the aortic valve (AV) area (AAV). The ALVOT is typically calculated using 2D echo assessments as the measured anterior–posterior (a/p) extension, assuming a round LVOT base. Anatomically, however, usually an elliptical shape of the LVOT base is present, with the long diameter extending from the medial–lateral axis (m/l), which is not recognized by two-dimensional (2D) echocardiography. Objective: We aimed to compare standard and three-dimensional (3D)-echocardiography-derived ALVOT calculation and its use in a standard CE (CEstd) and a modified CE (CEmod) to calculate the AAV vs. computed tomography (CT) multi-planar reconstruction (MPR) measurements of the anatomical ALVOT, and AAV, respectively. Methods: Patients were selected if 3D transthoracic echocardiography (TTE), 3D transesophageal echocardiography (TEE), and cardiac CT were all performed, and imaging quality was adequate. The ALVOT was assessed using 2D calculation, (a/p only), 3D-volume MPR, and 3D-biplane calculation (a/p and m/l). AAV was measured using both CEstd and CEmod, and 3D-volume MPR. Data were compared to corresponding CT analyses. Results: From 2017 to 2018, 107 consecutive patients with complete and adequate imaging data were included. The calculated ALVOT was smaller when assessed by 2D- compared to both 3D-volume MPR and 3D-biplane calculation. Calculated AAV was correspondingly smaller in CEstd compared to CEmod or 3D-volume MPR. The ALVOT and AAV, using data from 3D echocardiography, highly correlated and were congruent with corresponding measurements in CT. Conclusion: Due to the elliptic shape of the LVOT, use of measurements and calculations based on 2D echocardiography systematically underestimates the ALVOT and dependent areas, such as the AAV. Anatomically correct assessment can be achieved using 3D echocardiography and adapted calculations, such as CEmod.

Comparison of fluoroscopy and fluoroscopy-based 2D computer navigation for iliosacral screw placement: a retrospective study.

Treatment of pelvic fractures is often complicated. Here, we intended to evaluate the intraoperative benefits of using 2D computer navigation when compared with traditional fluoroscopy on X-ray burden, surgical time and screw placement accuracy. In this study, we retrospectively evaluated the records of 25 patients who underwent osteosynthesis of a posterior pelvic fracture using fluoroscopy at the University Hospital Ostrava, Czech Republic between 2011 and 2019, and 32 patients from the same department and period in whom 2D computer navigation was used. Intraoperative X-ray burden was significantly lower in the group with 2D computer navigation (median 650 vs 1024cGy/cm2), as was the duration of the surgery (41 vs 45min). This was most obvious where two screws were inserted (X-ray dose of 994 vs 1847cGy/cm2 and 48 vs 70min, respectively). Correction of the path for wire placement after the original drilling was necessary in 2 patients (6%) from the 2D computer navigation group and 15 patients from the fluoroscopy group (60%). Still, no malposition of the screws nor dislocation of the posterior pelvic segment after 12months was observed in any patient of either group; of complications, only three superficial infections in the 2D navigation group and 2 in the fluoroscopy group were observed. 2D computer navigation is a safe and accurate method for placement of screws during posterior pelvic fracture osteosynthesis, associated with lower intraoperative radiation burden and shorter surgical times compared to standard fluoroscopy, especially if two screws are inserted.

Estimation of zero sequence impedance in power transformers using 2D and 3D FEM

This paper describes calculation of zero sequence impedance in three phase, three leg core type power transformers using 2D and 3D finite element method (FEM) calculation on example of 100 MVA power transformer. Paper also describes how winding connection and arrangement affects the size and calculation of zero sequence impedance.

Fast computation of the Lorentz force induced by longitudinal electromagnetic stirring

In this work, we revisit a recent transient three-dimensional (3D) model for longitudinal electromagnetic stirring in the continuous casting of rectangular steel blooms. Whereas the earlier work was able to demonstrate accurate approximations to the solutions in two asymptotic limits, both of which gave economical alternatives to time-consuming 3D computations, here we show that the original governing equations can be manipulated to a form that allows for rapid computation even outside of these asymptotic limits. The resulting formulation requires the numerical solution of two steady-state complex Helmholtz-like equations in two dimensions that are coupled via a non-standard internal interface condition that is reminiscent of that occurring in the study of Marangoni convection; these equations are then solved numerically using the finite-element software Comsol Multiphysics. With this formulation, it is possible to compute the time-averaged Lorentz force components in a way that requires around four orders of magnitude less computational time than the fully 3D approach.

Transcatheter aortic valve replacement for bicuspid aortic valve disease: does conventional surgery have a future?

Bicuspid aortic valve (BAV) disease is the most common form of congenital heart valve defect. It is associated with aortic stenosis (AS), aortic insufficiency, and aortopathy. Treatment of severe AS requires valve replacement which historically has been performed with surgical aortic valve replacement (SAVR). Recently, transcatheter aortic valve replacement (TAVR) has emerged as a promising alternative. However, increased rates of adverse outcomes following TAVR have been shown in BAV patients with high amounts of calcification. Comparison between TAVR and SAVR in low surgical risk BAV patients in a randomized trial has not been performed and TAVR for BAV long-term performance is unknown due to lack of clinical data. Due to the complexity of BAV anatomies and the significant knowledge gap from the lack of clinical data, SAVR still has many benefits over TAVR in low surgical risk BAV patients. It also remains common for BAV patients to have an aortopathy, which currently can be treated with surgical techniques. This review aims to outline BAV associated diseases and their treatment strategies, the main TAVR adverse outcomes associated with anatomically complex BAV patients, TAVR strategies for mitigating these risks and the current state of cutting-edge 3D printing and computer modeling screening methods that can provide otherwise unobtainable preoperative information during the BAV patient selection process for TAVR.