This study describes the internal structure of materials used to produce medical stents. A two-level elastoviscoplastic mathematical model, which sets the parameters and describes the processes at the grain level, was developed and numerically implemented. A separate study was conducted to identify the most dangerous deformation modes in the balloon-expandable stent placement using the finite-element method in COMSOL Multiphysics. As a result, the challenging strain state type required for setting the kinematic loading on a representative macrovolume in the two-level model was obtained. A yield surface for different deformation paths in the principal deformation space for stainless steel AISI 316L was obtained and the effect of grain size on the deformation behavior of this material was explored using the developed model.
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http://dx.doi.org/10.3390/ma15196948 | DOI Listing |
Materials (Basel)
October 2022
Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Leicestershire LE11 3TU, UK.
This study describes the internal structure of materials used to produce medical stents. A two-level elastoviscoplastic mathematical model, which sets the parameters and describes the processes at the grain level, was developed and numerically implemented. A separate study was conducted to identify the most dangerous deformation modes in the balloon-expandable stent placement using the finite-element method in COMSOL Multiphysics.
View Article and Find Full Text PDFOrthop Surg
October 2022
Department of Orthopaedics, Zhejiang Hospital, Hangzhou, China.
Background: Vertebral artery injury (VAI) during cervical spine surgery is rare. Anterior controllable ante-displacement and fusion (ACAF) surgery is a novel technique for treating degenerative cervical spine disorders, especially ossification of the posterior longitudinal ligament. To date, there have been no reports of VAI during cervical ACAF surgery.
View Article and Find Full Text PDFZh Nevrol Psikhiatr Im S S Korsakova
August 2019
Pirogov Russian National Research Medical University, Moscow, Russia; Buyanov City Clinical Hospital, Moscow, Russia.
The paper presents the literature data concerning the results and surgical approaches to the treatment of tandem occlusion in the ICA system. The authors describe two clinical cases of endovascular treatment of tandem ipsilateral occlusion of ICA and middle cerebral artery (MCA). In both cases, the cause of two-level occlusion was complicated by thrombosis atherosclerotic plaque in ICA in the extracranial part with distal thromboembolism in SMA.
View Article and Find Full Text PDFAsian Cardiovasc Thorac Ann
January 2018
1 Department of Thoracic and Cardiovascular Surgery, Rennes University Hospital Center, Rennes, France.
Bronchobiliary fistula is a rare pathology mainly caused by hepatic tumors, bile duct obstruction, or hepatic hydatid disease. A 70-year-old man developed a bronchobiliary fistula after biliary stenting. After failure of conservative treatment including endoscopic retrograde biliary drainage, he underwent a combined operation with a two-level approach.
View Article and Find Full Text PDFJ Pediatr Surg
December 2017
Oregon Health & Science University, Department of Surgery, Division of Pediatric Surgery, Portland, OR; Legacy Emanuel Medical Center-Randall Children's Hospital, Portland, OR.
Background: Despite increases in imaging guidelines for other body-regions during initial trauma assessment and the demonstrated utility of chest radiographs (CXR), guidelines for use of thoracic computed-tomography (TCT) are lacking. We hypothesized that TCT utilization had not decreased relative to other protocolized CTs, and mechanism and CXR could together predict significant injury independent of TCT.
Methods: We performed a retrospective review of blunt trauma patients ≤18 y.
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