Long Chen¹, Ting Li¹, Liang Liu¹, Wenshuo Wang^2,*, Xiaoxiao Du³, Wei Wang³

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 2773-2806, 2024, DOI:10.32604/cmes.2024.046641

Abstract This study explores the implementation of computed tomography (CT) reconstruction and simulation techniques for patient-specific valves, aiming to dissect the mechanical attributes of calcified valves within transcatheter heart valve replacement (TAVR) procedures. In order to facilitate this exploration, it derives pertinent formulas for 3D multi-material isogeometric hyperelastic analysis based on Hounsfield unit (HU) values, thereby unlocking foundational capabilities for isogeometric analysis in calcified aortic valves. A series of uniaxial and biaxial tensile tests is executed to obtain an accurate constitutive model for calcified active valves. To mitigate discretization errors, methodologies for reconstructing volumetric parametric models, integrating both geometric and material… More > Graphic Abstract

Tianyu Zhou¹, Liang Hao¹, Xin Xu^2,3, Meng Si^2,3, Lian Zhang^2,3,*

Energy Engineering, Vol.121, No.1, pp. 145-168, 2024, DOI:10.32604/ee.2023.042798

Abstract This paper discussed the experimental results of the performance of an organic Rankine cycle (ORC) system with an ultra-low temperature heat source. The low boiling point working medium R134a was adopted in the system. The simulated heat source temperature (SHST) in this work was set from 39.51°C to 48.60°C by the simulated heat source module. The influence of load percentage of simulated heat source (LPSHS) between 50% and 70%, the rotary valve opening (RVO) between 20% and 100%, the resistive load between 36 Ω and 180 Ω or the no-load of the generator, as well as the autumn and winter… More >

Seyed Ehsan Rafiee^*, M. M. Sadeghiazad

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-15, 2016, DOI:10.5098/hmt.7.13

Abstract The aim of this investigation is study on separation phenomenon inside a special vortex tube affected by structural and physical factors including; throttle diameter, nozzle number and injection pressure as well as the parametric optimization based on separation efficiency using experimental and 3D-CFD methods. The results show that convergent VT with Dth=5.5mm provides 30.01% and 20.04% higher cooling and heating effectiveness compared to basic model. As another result, the higher injection pressure, the higher cooling effectiveness. The cooling effectiveness improves (16.86%) with increase in slot number up to N=4, then decreases. The maximum disagreement between experimental and predicted values is… More >

Jae Gun Kwak¹, Eung Re Kim², Taeyoung Yun¹, Sungkyu Cho¹, Chang-Ha Lee², Woong-Han Kim^1,*

Congenital Heart Disease, Vol.18, No.3, pp. 325-336, 2023, DOI:10.32604/chd.2023.027758

Abstract Objectives: To access the effectiveness of our modified right-ventricular overhauling procedure on tricuspid valve (TV) growth in patients with pulmonary atresia with intact ventricular septum (PAIVS). Methods: We retrospectively reviewed 21 patients with PAIVS who underwent modified right ventricular overhauling (mRVoh) between 2008 and 2019 at two institutions. Our mRVoh consisted of wide resection of hypertrophied infundibular and trabecular muscle, peeling off fibrotic endocardial tissue in the right ventricle (RV) cavity, surgical pulmonary valvotomy, and Blalock-Taussig shunt or banding of ductus arteriosus under cardiopulmonary bypass. The TV annulus sizes were measured and analyzed using echocardiography before and after mRVoh. Results:… More > Graphic Abstract

Norman Aiad^1,2,3,7, Mark V. Sherrid^1,7, Adam J. Small¹, Youssef Elnabawi^1,7, Jodi Feinberg¹, Leon Axel^1,4, Ralph Mosca⁵, T. K. Susheel Kumar⁵, Michael Argilla⁶, Dan G. Halpern^1,7,*

Congenital Heart Disease, Vol.18, No.3, pp. 267-277, 2023, DOI:10.32604/chd.2023.025853

Abstract Introduction: We sought to investigate whether the development of sub-pulmonic systolic anterior motion (SAM) may be inherent to the anatomy of the the mitral valve (MV) or affected by external factors, such as a dilated right ventricle or chest abnormalities in d-looped transposition of the great arteries post atrial switch operation (d-TGA/AtS). Methods: Analysis was performed of clinical and cardiac imaging studies acquired on 19 adult patients with d-TGA/AtS (age 42 ± 6 years old, 56% male) between 2015–2019. Echocardiography data included mitral apparatus anatomy, and CT/MRI data included biventricular dimensions, function, and Haller index (HI) for pectus deformity. Results:… More >

Salah Alzghoul^1,*, Othman Smadi¹, Ali Al Bataineh², Mamon Hatmal³, Ahmad Alamm⁴

Intelligent Automation & Soft Computing, Vol.37, No.1, pp. 455-470, 2023, DOI:10.32604/iasc.2023.038338

Abstract Currently, the decision of aortic valve replacement surgery time for asymptomatic patients with moderate-to-severe aortic stenosis (AS) is made by healthcare professionals based on the patient’s clinical biometric records. A delay in surgical aortic valve replacement (SAVR) can potentially affect patients’ quality of life. By using ML algorithms, this study aims to predict the optimal SAVR timing and determine the enhancement in moderate-to-severe AS patient survival following surgery. This study represents a novel approach that has the potential to improve decision-making and, ultimately, improve patient outcomes. We analyze data from 176 patients with moderate-to-severe aortic stenosis who had undergone or… More >

Y. L. Zhang^a , H. B. Lin^b, S. P. Li^b,*, J. J. Xiao^a, L. Zhang^c

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.47

Abstract Centrifugal pumps need to be stopped in the case of closing valve sometimes due to some specific application requirements. This paper presents a numerical simulation of the unsteady flow inside a low specific speed centrifugal pump during closed-valve forward and reverse stopping process. The study results show that the average internal pressure gradually decreases during stopping periods. At the same blade radius, the pressure on working surface is significantly higher than the suction surface. The pressure gradually increases from the impeller inlet to the outlet. The simulation fully shows the transient flow characteristics inside the centrifugal pump during forward and… More >

Jingnan Zhang¹, Junyi Wan¹, Yihang Li², Yu Han², Jiahua Pan³, Fang Fang¹, Shiliang Jiang⁴, Xiangbin Pan¹, Gejun Zhang^1,*

Congenital Heart Disease, Vol.18, No.2, pp. 219-234, 2023, DOI:10.32604/chd.2023.027562

Abstract Background: The Venus-P valve was the first self-expanding valve used world-wide for transcatheter pulmonary valve replacement (TPVR) in patients with severe pulmonary regurgitation (PR). We intended to report the extended follow-up results from the prospective trial (No. NCT02590679). Methods: A total of 38 patients with severe PR (mean age 24.2 ± 13.2) were included. Follow-up data were obtained after implanted at 1, 6, and 12 months and yearly after. The frame geometry was assessed on post-implant computer tomography (CT) scanning by calculating the non-circularity [circularity ratio (minimum diameter/maximum diameter) < 0.9] and under-expansion [expansion ratio (derived external valve area/nominal external valve area)… More > Graphic Abstract

Cherith Somerville^1,2, Kelsey Kalbfleisch^1,2, Roozbeh Manshaei^1,2, Qiliang Ding^1,2, John B.A. Okello^1,2,3, Rachel Silver⁴, David Chitayat^2,4, Varsha Thakur⁵, Olivier Villemain^5,6,7, Rebekah Jobling^1,2,8,*

Congenital Heart Disease, Vol.18, No.2, pp. 213-218, 2023, DOI:10.32604/chd.2023.023042

Abstract We report a three-year-old male child who presented with congenital valvular defects, right ventricular malformation, and initial developmental delay. Genome sequencing showed rare deleterious biallelic missense variants in PLD1. In his parents’ second pregnancy, echocardiogram at 13 weeks gestation revealed right-sided cardiac malformations resembling the clinical presentation of the family’s first child. Targeted DNA analysis showed that the fetus carried the same biallelic PLD1 variants as their older sibling. This case helps to further delineate the clinical spectrum of PLD1-related defects and highlights the value of both genome sequencing in congenital heart disease and early fetal echocardiography to establish phenotype. More >

Supaporn Roymanee^1,*, Nantawan Su-angka^1,2, Worakan Promphan^2,3,*, Kanjarut Wongwaitaweewong¹, Jirayut Jarutach¹, Rujira Buntharikpornpun¹, Pimpak Prachasilchai^2,3

Congenital Heart Disease, Vol.18, No.2, pp. 169-181, 2023, DOI:10.32604/chd.2023.021238

Abstract Background: Ventricular septal defect (VSD) is the most common congenital heart disease. Transcatheter VSD closure is an effective treatment for patients with muscular and perimembranous VSD. However, there is a limit data for outlet VSD, especially impact to the aortic valve leaflet after transcatheter closure. This study aims to assess the outcomes of transcatheter closure of the outlet-type ventricular septal defect (OVSD) after 1 postoperative year. Methods: A retrospective study was performed including 50 patients who underwent transcatheter (n = 25) and surgical (n = 25) OVSD closure during the exact time frame at two medical centres. Results: The median age and body weight… More > Graphic Abstract