The accuracy and clinical applicability of a sensor based electromagnetic nonfluoroscopic catheter tracking system

Shinya Yamada,Li-Wei Lo,Yenn-Jiang Lin,Shih-Lin Chang,Fa-Po Chung,Yu-Feng Hu,Ta-Chuan Tuan,Tze-Fan Chao,Jo-Nan Liao,Chin-Yu Lin,Shih-Ann Chen 대한심장학회 2019 Korean Circulation Journal Vol.49 No.1

Background and Objectives: The differences between electromagnetic-based mapping (EM) and impedance-based mapping (IM) in 3D anatomical reconstruction have not been fully clarified. We aimed to investigate the anatomical accuracy between EM (MediGuide™) and IM (EnSite Velocity™) systems. Methods: We investigated 15 consecutive patients (10 males, mean age 58±9 years) who underwent pulmonary veins (PVs) isolation for paroxysmal atrial fibrillation (PAF). Contrast-enhanced computed tomography (CT) image of the left atrium (LA) was acquired before ablation and the 3D geometry of the LA was constructed using EM during ablation procedure. We measured the 4 PV angles between the main trunk of each PV and the posterior LA after field scaling. Additionally, the posterior LA surface area was measured. The variables were compared to those of CT-based geometry. A control group of 40 patients who underwent conventional PVs isolation using IM were also evaluated. Results: The actual and relative changes of EM and CT-based geometry in all PV angles and posterior LA were significantly smaller compared to those of IM and CT-based geometry. Intraclass correlation coefficient (ICC) between EM and CT-based geometry were 0.871 (right superior pulmonary vein [RSPV]), 0.887 (right inferior pulmonary vein [RIPV]), 0.853 (left superior pulmonary vein [LSPV]), 0.911 (left inferior pulmonary vein [LIPV]), and 0.833 (posterior LA). On the other hand, ICC between IM and CT-based geometry were 0.548 (RSPV), 0.639 (RIPV), 0.691 (LSPV), 0.706 (LIPV), and 0.568 (posterior LA). Conclusions: Image integration with EM enables high accurate visualization of cardiac anatomy compared to IM in PAF ablation.

Multiscale Modeling of Concrete in Anchorage Region of Post-Tensioned NSM CFRP

Kim, Yail J.,Ji, Yongcheng,Chang, Wei-Tze,Kang, Jae-Yoon,Park, Jong-Sup,Jung, Woo-Tai American Concrete Institute 2016 ACI structural journal Vol.113 No.6

<P>This paper presents a multiscale modeling approach to understand the behavior of anchorage concrete in prestressed concrete bridge girders strengthened with post-tensioned near-surfacemounted (NSM) carbon fiber-reinforced polymer (CFRP) strips. The macroscale, mesoscale, and microscale responses of the concrete are represented by continuum finite element, discrete-object physics, and analytical representative element models, respectively. Domain decomposition and integration are implemented in accordance with an information-passing mechanism. The post-tensioned NSM CFRP results in macroscale strain softening near the anchorage and it also causes a regional net strain increase responsible for macroscale and microscale damage. The existence of a rapid crack-propagation phase is ascertained in the anchorage concrete from a mesoscale standpoint, which influences stress transfer from the anchor bolt to the contiguous concrete. The microscale damage of the concrete rapidly propagates when mechanical distress is applied due to post-tensioning the NSM CFRP and stabilizes with a decrease in stress transfer from the cementitious binder to aggregate inclusion in the representative element. The concept of effective stress is proposed to link the macroscale and microscale responses of the anchorage concrete.</P>

Catheter Ablation of Ventricular Tachycardia in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

Fa-Po Chung,Chin-Yu Lin,Yenn-Jiang Lin,Shih-Lin Chang,Li-Wei Lo,Yu-Feng Hu,Ta-Chuan Tuan,Tze-Fan Chao,Jo-Nan Liao,Ting-Yung Chang,Shih-Ann Chen 대한심장학회 2018 Korean Circulation Journal Vol.48 No.10

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is predominantly an inherited cardiomyopathy with typical histopathological characteristics of fibro-fatty infiltration mainly involving the right ventricular (RV) inflow tract, RV outflow tract, and RV apex in the majority of patients. The above pathologic evolution frequently brings patients with ARVD/C to medical attention owing to the manifestation of syncope, sudden cardiac death (SCD), ventricular arrhythmogenesis, or heart failure. To prevent future or recurrent SCD, an implantable cardiac defibrillator (ICD) is highly desirable in patients with ARVD/C who had experienced unexplained syncope, hemodynamically intolerable ventricular tachycardia (VT), ventricular fibrillation, and/or aborted SCD. Notably, the management of frequent ventricular tachyarrhythmias in ARVD/C is challenging, and the use of antiarrhythmic drugs could be unsatisfactory or limited by the unfavorable side effects. Therefore, radiofrequency catheter ablation (RFCA) has been implemented to treat the drug-refractory VT in ARVD/C for decades. However, the initial understanding of the link between fibro-fatty pathogenesis and ventricular arrhythmogenesis in ARVD/C is scarce, the efficacy and prognosis of endocardial RFCA alone were limited and disappointing. The electrophysiologists had broken through this frontier after better illustration of epicardial substrates and broadly application of epicardial approaches in ARVD/C. In recent works of literature, the application of epicardial ablation also successfully results in higher procedural success and decreases VT recurrences in patients with ARVD/C who are refractory to the endocardial approach during long-term follow-up. In this article, we review the important evolution on the delineation of arrhythmogenic substrates, ablation strategies, and ablation outcome of VT in patients with ARVD/C.

Application of Robotic Welding Technology to the Continuity Plate Weld Within a Steel Built-up Box Column in Buildings

Chung-Che Chou,Gee‑Jin Yu,Kung‑Juin Wang,Wei‑Tze Chang,Chiun‑Lin Wu,Charlene Chin‑Jie Zhao,Chun‑Yao Yang,Ming‑Ti Chou 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.9

This paper presents a study to investigate the feasibility of using robotic welding technologies to weld the continuity plate and the column flange plate during manufacturing steel built-up box columns in buildings. Specimens designed to emulate the key components in the steel beam-to-column moment connections for Special moment frame were fabricated and welded using a proposed automated procedure that performs multi-layer, multi-pass welding for thick steel plates. Effects of controlling parameters on robotic welding results that includes the manner of bead stacking, wire feed speed, travel speed, working angle, arc voltage, the path of the welding pass, and the methods to start and finish welding passes were investigated. The quality of the welded products was assessed by visual inspection and ultrasonic testing (UT). Further mechanical tests including tensile tests, bending tests, and cyclic loading tests were carried out on selected welded products that passed the UT examination. The test results indicated that the robotic welds showed no visible damage or cracks, met requirements specified in the AWS specification, and exhibited satisfactory strength and ductility.

The Antiproliferation Activity of Ganoderma formosanum Extracts on Prostate Cancer Cells

( Cheng-yen Chiang ),( Kai-di Hsu ),( Yen-yi Lin ),( Chang-wei Hsieh ),( Jui-ming Liu ),( Tze-ying Lu ),( Kuan-chen Cheng ) 한국균학회 2020 Mycobiology Vol.48 No.3

Androgen-independent prostate cancer accounts for mortality in the world. In this study, various extracts of a medical fungus dubbed Ganoderma formosanum were screened for inhibition of DU145 cells, an androgen-independent prostate cancer cell line. Results demonstrated that both hexane (GF-EH) and butanol (GF-EB) fraction of G. formosanum ethanol extract inhibited DU145 cell viability in a dose-dependent manner. GF-EH induced cell-cycle arrest in G1 phase of DU145 cells via downregulation of cyclin E2 protein expression. In addition, GF-EB triggered extrinsic apoptosis of DU145 cells by activating caspase 3 gene expression resulting in programed cell death. Above all, both GF-EH and GF-EB show lower toxicity to normal human fibroblast cell line compared to DU145 cell, implying that they possess specific drug action on cancer cells. This study provides a molecular basis of G. formosanum extract as a potential ingredient for treatment of androgen-independent prostate cancer.