scholarly journals Finite Element Studies of Triple Actuation of Shape Memory Alloy Wires for Surgical Tools

2018 ◽  
Author(s):  
Bardia Konh
Keyword(s):  
Shape Memory ◽  
Artificial Heart ◽  
Heart Valves ◽  
Engineering Systems ◽  
Design And Development ◽  
Orthodontic Wires ◽  
Recoverable Strain ◽  
Artificial Heart Valves ◽  
Innovative Products ◽  
Superelastic Behavior

Since the early discovery in 1951 [1], shape memory alloys (SMAs) have been used in design and development of several innovative engineering systems. SMAs’ unique characteristics have introduced unconventional alternatives in design and development of advanced devices. SMA’s field of applications has covered many areas from aerospace to auto industries, and medical devices [2]. During the past couple of decades, scientists have suggested material models to predict the SMA’s shape memory effect (SME) and its superelastic behavior. The superelastic characteristic of SMAs (its capability to exhibit a large recoverable strain) has been widely used to develop innovative products including biomedical implants such as stents, artificial heart valves, orthodontic wires, frames of indestructible spectacles, etc. However, its actuation capabilities, known as SME, hasn’t been thoroughly expanded. The number of products privileging from SMA’s SME behavior has been very limited. The reason relies on the SMA’s complex material properties that depend on the stress, strain and temperature at every stage of actuation as well as the material’s processing and the thermomechanical loading history.

scholarly journals Numerical Study of Blood Flow Through Artificial Heart Valves

2021 ◽  
Vol 1094 (1) ◽  
pp. 012120
Author(s):  
Hussein Togun ◽  
Ali Abdul Hussain ◽  
Saja Ahmed ◽  
Iman Abdul hussain ◽  
Huda Shaker
Keyword(s):  
Blood Flow ◽  
Artificial Heart ◽  
Heart Valves ◽  
Numerical Study ◽  
Artificial Heart Valves ◽  
Flow Through

On polymeric mobile elements in artificial heart valves and changes occurring in these elements under the action of the blood and its components

1977 ◽  
Vol 19 (6) ◽  
pp. 1537-1544
Author(s):  
E.I. Semenenko ◽  
A.I. Ivanov ◽  
M.A. Markelov ◽  
N.B. Dobrova ◽  
Ye.V. Smurova ◽  
...  
Keyword(s):  
Artificial Heart ◽  
Heart Valves ◽  
Mobile Elements ◽  
Artificial Heart Valves

The course of pregnancy in patients with artificial heart valves

1976 ◽  
Vol 61 (4) ◽  
pp. 504-512 ◽  
Author(s):  
Carlos Ibarra-Perez ◽  
Noel Arevalo-Toledo ◽  
Octavio Alvarez-De La Cadena ◽  
Luis Noriega-Guerra
Keyword(s):  
Artificial Heart ◽  
Heart Valves ◽  
Artificial Heart Valves

ARTIFICIAL HEART VALVES

The Lancet ◽  
1962 ◽  
Vol 280 (7266) ◽  
pp. 1171 ◽  
Author(s):  
R.W.M. Frater
Keyword(s):  
Artificial Heart ◽  
Heart Valves ◽  
Artificial Heart Valves

Time-dependent Morphological Alterations Caused by Crimping of Artificial Heart Valves

2010 ◽  
Vol 143 (4) ◽  
pp. 331
Author(s):  
H. Aupperle ◽  
F. Gruenwald ◽  
P. Kiefer ◽  
J. Kempfert ◽  
T. Walther ◽  
...  
Keyword(s):  
Artificial Heart ◽  
Heart Valves ◽  
Time Dependent ◽  
Morphological Alterations ◽  
Artificial Heart Valves

Hydrodynamics of artificial heart valves

1976 ◽  
Vol 11 (4) ◽  
pp. 645-648
Author(s):  
I. B. Rozanova
Keyword(s):  
Artificial Heart ◽  
Heart Valves ◽  
Artificial Heart Valves

Polyurethane artificial heart valves in animals

1959 ◽  
Vol 14 (6) ◽  
pp. 1045-1048 ◽  
Author(s):  
Tetsuzo Akutsu ◽  
Barend Dreyer ◽  
Willem J. Kolff
Keyword(s):  
Artificial Heart ◽  
Heart Valves ◽  
Artificial Heart Valves

PIV Measurements of Flow in a Centrifugal Blood Pump: Steady Flow

2004 ◽  
Vol 127 (2) ◽  
pp. 244-253 ◽  
Author(s):  
Steven W. Day ◽  
James C. McDaniel
Keyword(s):  
Shear Stress ◽  
Artificial Heart ◽  
Heart Valves ◽  
Blood Pump ◽  
Reynolds Stresses ◽  
Centrifugal Blood Pump ◽  
Flow Rates ◽  
Blood Damage ◽  
Artificial Heart Valves ◽  
Stagnant Flow

Magnetically suspended left ventricular assist devices have only one moving part, the impeller. The impeller has absolutely no contact with any of the fixed parts, thus greatly reducing the regions of stagnant or high shear stress that surround a mechanical or fluid bearing. Measurements of the mean flow patterns as well as viscous and turbulent (Reynolds) stresses were made in a shaft-driven prototype of a magnetically suspended centrifugal blood pump at several constant flow rates (3–9L∕min) using particle image velocimetry (PIV). The chosen range of flow rates is representative of the range over which the pump may operate while implanted. Measurements on a three-dimensional measurement grid within several regions of the pump, including the inlet, blade passage, exit volute, and diffuser are reported. The measurements are used to identify regions of potential blood damage due to high shear stress and∕or stagnation of the blood, both of which have been associated with blood damage within artificial heart valves and diaphragm-type pumps. Levels of turbulence intensity and Reynolds stresses that are comparable to those in artificial heart valves are reported. At the design flow rate (6L∕min), the flow is generally well behaved (no recirculation or stagnant flow) and stress levels are below levels that would be expected to contribute to hemolysis or thrombosis. The flow at both high (9L∕min) and low (3L∕min) flow rates introduces anomalies into the flow, such as recirculation, stagnation, and high stress regions. Levels of viscous and Reynolds shear stresses everywhere within the pump are below reported threshold values for damage to red cells over the entire range of flow rates investigated; however, at both high and low flow rate conditions, the flow field may promote activation of the clotting cascade due to regions of elevated shear stress adjacent to separated or stagnant flow.

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