1,676 research outputs found

    Laser beam cutting and welding of coronary stents

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    Coronary stents are thin-walled and mesh-structured metallic implants, which are made generally by laser beam cutting of high-precision tubes of 90-120 micrometer thickness. The tube material can be 316L stainless steel or L605 type cobalt-chromium alloy. The paper present how laser settings influence geometry and surface quality of the kerf and residual stresses, which play very important role in the precision of stent strut homogeneity. Hungarian Tentaur stent was developed 15 years ago. This coil stent made of 145 micrometers thick stainless steel wire contains 9-25 joints produced by electric resistance projection welding. Developments were bringing out for increasing flexibility of Tentaur stent, and a new design and a new tech-nology was elaborated, which’s based on laser beam mi-crowelding. TentaFlex stent also is constructed from austenitic stainless steel wire, but it does not contain any wire-crossing joint, because stent struts are configured from sinusoidal helix. Stent contains only two welded joints at its ends. Laser welding experiences of these joints are presented in the paper. A Trumpf PowerWeld Nd:YAG laser work station was used for welding, and after optimization of laser settings joints can’t produces from only one side of the coiled stent

    Coronary Arterial Drug-Eluting Stent: From Structure to Clinical

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    Endothelialization of Intravascular Stents

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    Wide clinical application of intravascular stenting devices is currently limited by occlusion or intraluminal narrowing caused by thrombosis and neointimal thickening in a considerable percentage of implantations. We studied the possibility of seeding one of the currently availiable stents, a stainless steel, self‐expandable wire‐mesh, with endothelial cells in vitro. Endothelial cells, derived from human umbilical cord veins, could be successfully attached to stent filaments. In vivo stent implantations in porcine femoral arteries showed complete covering of stent wires by endothelium after 1 week. We conclude that coating of stents with autologous endothelial cells prior to implantation might protect against early thrombosis during the period in which a neointima is formed. (J Interven Cardiol 1988:1:2) Copyrigh

    EUR-ASSESS Project Subgroup Report on Coverage

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    The issue of health benefits coverage—and its relation to health technology assessment (HTA)—has gained increasing attention in recent years. Economic constraints on health care, as well as the rapid pace of technological change, have forced European countries to face difficult choices in providing such care. The active use of coverage decision making has been proposed as a tool to help rationalize health care, and HTA has been advocated as a necessary activity to improve coverage decision

    Occupational Radiation Exposure Health Risks And Radiation Safety Practices Relative to Interventional Cardiology Providers

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    Background: Occupational radiation exposure is a health risk for many healthcare professionals working in interventional cardiology. As technology has progressed, interventional procedures have become more complex and subsequently longer in radiation exposure duration, resulting in a need for radiation safety practices to meet the ever growing demands of the interventional team and ideally outpace these demands. Methods: A comprehensive systematic literature review was conducted using PubMed. Articles on the health risks of occupational radiation exposure were selected to demonstrate the breadth of potential adverse effects of radiation exposure with less focus on the depth of these effects. Articles covering occupational radiation safety practices were selected with a focus on radiation safety practices relative to body region and procedural aspects. Results: Brain cancer, cataracts, cardiovascular disease, thyroid disease, mental health conditions, skin lesions, and orthopedic problems are some of the most prevalent occupational radiation exposure health risks. Fortunately, these risks have largely been reduced through utilization of personal and ancillary radiation shielding and improved procedural aspects. Conclusion: Radiation is invisible and adverse effects may not present until years later, which may result in interventional cardiology providers becoming complacent and less vigilant with radiation safety practices. Furthermore, some interventional cardiology providers utilize suboptimal radiation safety practices due to perceived inconveniences and discomfort as well as the belief that optimal radiation safety practices may risk image quality and procedural efficiency. Ultimately, the greatest occupational radiation exposure reductions result from the reduction of radiation exposure to the patient due to reduced radiation scatter

    Cardiovascular: Outcomes and Innovations Report

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    2020 Annual Reporthttps://knowledgeconnection.mainehealth.org/annualreports/1011/thumbnail.jp

    Polymeric endovascular strut and lumen detection algorithm for intracoronary optical coherence tomography images

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    Polymeric endovascular implants are the next step in minimally invasive vascular interventions. As an alternative to traditional metallic drug-eluting stents, these often-erodible scaffolds present opportunities and challenges for patients and clinicians. Theoretically, as they resorb and are absorbed over time, they obviate the long-term complications of permanent implants, but in the short-term visualization and therefore positioning is problematic. Polymeric scaffolds can only be fully imaged using optical coherence tomography (OCT) imaging—they are relatively invisible via angiography—and segmentation of polymeric struts in OCT images is performed manually, a laborious and intractable procedure for large datasets. Traditional lumen detection methods using implant struts as boundary limits fail in images with polymeric implants. Therefore, it is necessary to develop an automated method to detect polymeric struts and luminal borders in OCT images; we present such a fully automated algorithm. Accuracy was validated using expert annotations on 1140 OCT images with a positive predictive value of 0.93 for strut detection and an R^2 correlation coefficient of 0.94 between detected and expert-annotated lumen areas. The proposed algorithm allows for rapid, accurate, and automated detection of polymeric struts and the luminal border in OCT images

    Emerging of cardiovascular metal stent: a review on drug-eluting stent towards the utilisation of herbal coating

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    Metal stents used in the treatment of percutaneous coronary intervention (PCI) have revolutionized in treating atherosclerosis disease. Starting from the emergence of bare metal stent (BMS), this stent has been progressively developed into drug-eluting stent (DES) and biodegradable stent. By focusing on DES, various drugs have been used to coat metal stent with the aims to overcome in-stent restenosis and stent thrombosis. Therefore, the utilisation of various drugs and polymers as coating materials was reviewed in this study to identify possible alternative to overcome the current DES problems. Even though, both complications of BMS are covered successfully by DES, however, DES projects long term complications of delayed endotheliasation, delayed wound healing and late stent thrombosis. Another alternative of herb coating on DES is considered to be a potential approach in improving endotheliasation and retarding smooth muscle cells proliferation to accelerate wound healing and to prevent late stent thrombosis

    Current cardiac imaging techniques for detection of left ventricular mass

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    Estimation of left ventricular (LV) mass has both prognostic and therapeutic value independent of traditional risk factors. Unfortunately, LV mass evaluation has been underestimated in clinical practice. Assessment of LV mass can be performed by a number of imaging modalities. Despite inherent limitations, conventional echocardiography has fundamentally been established as most widely used diagnostic tool. 3-dimensional echocardiography (3DE) is now feasible, fast and accurate for LV mass evaluation. 3DE is also superior to conventional echocardiography in terms of LV mass assessment, especially in patients with abnormal LV geometry. Cardiovascular magnetic resonance (CMR) and cardiovascular computed tomography (CCT) are currently performed for LV mass assessment and also do not depend on cardiac geometry and display 3-dimensional data, as well. Therefore, CMR is being increasingly employed and is at the present standard of reference in the clinical setting. Although each method demonstrates advantages over another, there are also disadvantages to receive attention. Diagnostic accuracy of methods will also be increased with the introduction of more advanced systems. It is also likely that in the coming years new and more accurate diagnostic tests will become available. In particular, CMR and CCT have been intersecting hot topic between cardiology and radiology clinics. Thus, good communication and collaboration between two specialties is required for selection of an appropriate test
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