Finite Element Analysis on Stellite 17mm Tube Valve for Pediatric Ventricular Assist Device

2017 ◽  
Author(s):  
Christopher M. Scheib ◽  
Raymond K. Newswanger ◽  
Allison M. Beese ◽  
Timothy Bowen ◽  
Gregory S. Lewis ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Ventricular Assist Device ◽  
Structural Reliability ◽  
Cobalt Chromium ◽  
Assist Device ◽  
Element Analysis ◽  
Ventricular Assist ◽  
Material Choice

A Stellite 25 17mm tube valve based upon the Björk-Shiley Monostrut (BSM) valve design was developed for use in the Penn State Pediatric Ventricular Assist Device (PVAD) pump [1]. The hook of the valve was designed to hold a Delrin occluding disc in place while allowing the disc to tilt open 70 degrees from the closed position. Unlike common design constraints which remain in the elastic region, the hook experiences plastic deformation twice during the assembly process, making the material choice of Stellite 25 imperative. Stellite 25 is a cobalt-chromium-tungsten-nickel alloy (Co-20Cr-15W-10Ni) belonging to the material family of superalloys which are commonly used for wear-resistant applications exposed to heat, abrasion, and galling [2, 3]. Along with its excellent in vivo corrosion resistance [4], Stellite 25 exhibits high strength and ductility which permit the hook to be plastically deformed during disc installation while remaining below the strain to failure [3, 4]. Together these qualities make Stellite 25 an ideal material choice for the 17mm tube valve application. Predicting the resultant stresses and strains is critical for determining the safety and structural reliability of the Stellite 25 17mm tube valve for the PVAD after assembly. After performing finite element analysis (FEA), the simulation results were validated by deflection experiments and metallurgical investigations.

In vivo testing of a pulsatile implantable impeller pump as a left ventricular assist device used in calves

Perfusion ◽  
1995 ◽  
Vol 10 (4) ◽  
pp. 257-263 ◽  
Author(s):  
KX Qian ◽  
SS Wang ◽  
SH Chu
Keyword(s):  
Left Ventricular Assist Device ◽  
Ventricular Assist Device ◽  
Left Ventricular ◽  
Assist Device ◽  
Ventricular Assist ◽  
Left Ventricular Assist ◽  
Mean Pressure ◽  
In Vivo Testing ◽  
Serum Glutamic Oxalacetic Transaminase

A pulsatile implantable impeller pump was tested as a left ventricular assist device in five calves. The experiments lasted for 4-11 days. Death or termination was mainly due to respiratory complications or bleeding, irrelevant to the pump itself. As indicators of haemolysis, thrombogenesis, renal and hepatic functions, free haemoglobin( FHb), haematocrit (Hct), platelet number (Plt), lactate dehydrogenase (LDH), blood urea nitrogen (BUN), creatinine, serum glutamic oxalacetic transaminase (GOT) and total bilirubin were measured preoperatively, at the beginning of the pumping (pump on), six hours later and every day thereafter. The data indicated that the pump caused no severe blood damage or organ dysfunction. Thus, the feasibility of a pulsatile centrifugal pump was demonstrated. The pump with its driver weighs 110 g and is capable of delivering a blood flow up to 8 l/min against 100 mmHg mean pressure.

scholarly journals Research on Bridge Structure Reliability Evaluation due to Vessels Collison Based on a Statistical Moment Method

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Tao Fu ◽  
Yang Liu ◽  
Zhixin Zhu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Moment Method ◽  
Structural Reliability ◽  
Statistical Moment ◽  
Bridge Structure ◽  
Element Analysis ◽  
Performance Function ◽  
Structural Resistance ◽  
Collision Force

Damage to bridge structures caused by vessel collision is a risk for bridges crossing water traffic routes. Therefore, safety around vessel collision of existing and planned bridges is one of the key technical problems that must be solved by engineering technicians and bridge managers. In the evaluation of the reliability of the bridge structure, the two aspects of vessel-bridge collision force and structural resistance need to be considered. As there are many influencing parameters, the performance function is difficult to express by explicit function. This paper combines the moment method theory of structural reliability with finite element analysis and proposes a statistical moment method based on finite element analysis for the calculation of vessel-bridge collision reliability, which solves the structural reliability problem with a nonlinear implicit performance function. According to the probability model based on current velocity, vessel velocity, and vessel collision tonnage, the estimate points in the standard normal space are converted into estimate points in the original state space through the Rosenblatt reverse transform. According to the estimate points in the original state space and the simplified dynamic load model of vessel-bridge collision, the sample time-history curve of random vessel-bridge collision force is generated, the dynamic response of the bridge structure and the structural resistance of the bridge are calculated by establishing a finite element model, and the failure probability and reliability index of the bridge structure is calculated according to the fourth-moment method. The statistical moment based on the finite element analysis is based on the finite element analysis and the moment method theory of structural reliability. The statistical moment of the limited performance function is calculated through a quite small amount of confirmatory finite element analysis, and the structural reliability index and failure probability are obtained. The method can be widely used in existing finite element analysis programs, greatly reducing the number of finite element analyses needed and improving the efficiency of structural reliability analysis.

scholarly journals Evaluation of the behavior system locator associated with a removable partial denture, finite element analysis

2018 ◽  
Vol 25 (2) ◽  
pp. 10
Author(s):  
Medardo Alexander Arenas-Chavarria ◽  
Samuel David Giraldo-Gómez ◽  
Federico Latorre-Correa ◽  
Junes Abdul Villarraga-Ossa
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Deformation ◽  
Vertical Direction ◽  
Cobalt Chromium ◽  
Removable Partial Denture ◽  
Element Analysis ◽  
Partial Denture ◽  
Solid Works ◽  
Von Mises

Aim: The purpose of this research was to evaluate the behavior of the system locator settings associated with distal extension removable partial denture lower (PPR) by finite element analysis (FEA). Materials and Methods: A Class II Kennedy 3D model using a CAD software Solid Works 2010 (SolidWorks Corp., Concord, MA, USA), and subsequently processed and analyzed by ANSYS Software version Model 14. One (1) was designed implant Tapered Screw -Vent® (ref TSVB10 Zimmer Dental-Carlsbad,CA,USA.) length x 10mm diameter 3.7mm with a 3.5mm platform, internal hexagon with its respective screw fixation; this was located at the tooth 37 as a rear pillar of a PPR, whose major connector was a lingual bar casting (alloy cobalt chromium), based combined (metal/ acrylic) with teeth to replace (37, 36 and 35). Efforts were evaluated von Mises in a 400N load. This analysis allowed assessing the performance of various prosthetic structures modeled and generated effects on bone-implant interface. Results: Differences between the values von Mises in all structures and loads were observed before there was no permanent deformation in any of them. Structures such as bone showed in normal values microstrain. Conclusions: The behavior of the PPRimplant connection, showed a favorable distribution efforts by using a PPR, subjecting it to load in the vertical direction.

In Vivo Evaluation of a Pneumatic Extracorporeal Ventricular Assist Device for up to 90 Day Support

ASAIO Journal ◽  
2016 ◽  
Vol 62 (6) ◽  
pp. 697-703 ◽  
Author(s):  
Jeff L. Conger ◽  
Brian W. Grace ◽  
Kelsey L. Van Noy ◽  
Kelly M. Handy ◽  
Gil G. Costas ◽  
...  
Keyword(s):  
Ventricular Assist Device ◽  
Assist Device ◽  
In Vivo Evaluation ◽  
Ventricular Assist
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