Mitral valve regurgitation is a relatively common and important heart valve lesion in clinical practice and adequate assessment is fundamental to decision on management, repair or replacement. Disease localised to the posterior mitral valve leaflet or focal involvement of the anterior mitral valve leaflet is most amenable to mitral valve repair, whereas patients with extensive involvement of th...

INTRODUCTION Native aortic valve leaflets contain a network of strong collagen fibers within a matrix of relatively distensible tissue. This composite structure leads to anisotropic mechanical properties and is believed to play an important role in the ability of the structure to withstand the stresses of cyclic loading over billions of heart beats. Replacement valves that consist of animal tis...

Prognostics technologies determine the health (or damage) state of a component or subsystem, and make end of life (EOL) and remaining useful life (RUL) predictions. Such information enables system operators to make informed maintenance decisions and streamline operational and mission-level activities. We develop a model-based prognostics methodology for pneumatic valves used in ground support e...

This paper introduces a very simple way to evaluate low stress shearing properties of woven fabrics with the advantages of simplicity and easy accessibility. A 200-gram load is applied on small portion of the sample instead of applying the load overall width of the fabric. As a result, buckling of the fabric will happen and the loading-unloading curve will show the behavior of the fabric during...

the morphologic characteristics of the mitral valve (i.e., simple mitral valve prolapse vs. flail leaflet or the presence of severe myxomatous infiltration), cannot yet be analyzed. Recently, it has been suggested that mitral valve prolapse is uniformly a good prognosis (3). It is unclear how these various components of the clinical presentation of patients with mitral valve diseases contribute...

Industrial Automation is a broad field among other engineering disciplines. The major activities of Automation stem from manufacturing industries and include cycle time improvement, productivity improvement, cost reduction, efficiency improvement, materials handling, analyze and improve the work methods, to eliminate waste and proper allocation and utilization of resources. Automation in a manu...

Some prosthetic heart valves with Silastic ball poppets undergo degeneration and variance. The problem is avoided with metal poppets; however, their impact can damage the cloth coverings on the struts, resulting in distorted blood flow paths. Consequently, renewed interest in mOd-cured Silastic poppets and inserts is developing. With photostress equipment, we analyzed two spherical poppet model...

BACKGROUND Mechanical valves and bioprostheses are widely used for aortic valve replacement. Though previous randomised studies indicate that there is no important difference in outcome after implantation with either type of valve, knowledge of outcomes after aortic valve replacement is incomplete. OBJECTIVE To predict age and sex specific outcomes of patients after aortic valve replacement w...

The valves in reciprocating compressors use springs to control the timing of the valve closing. These springs are subjected to dynamic loading by the motion of the valve element. The element motion is periodic, but includes rapid acceleration and deceleration. It can therefore excite a wide range of frequencies in the spring. The resulting spring surge creates high stresses and is a major contr...

Background This study was performed to determine independent predictors of long-term outcome after percutaneous balloon dilation of congenital pulmonary valve stenosis. Smaller follow-up series of patients after balloon pulmonary valvuloplasty have shown inconsistent results regarding the independent relation between prognostic factors and longterm outcome, as many patient selection and technic...