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Double dump valves have two trap-door flap plates which open and close on an alternating cycle. The top gate opens to allow collected material to drop through onto the bottom gate. The top gate then re-closes to prevent air leakage above the valve. The bottom gate then opens to allow material to pass completely through the valve.
Mitral regurgitation is the most common form of mitral valve dysfunction. Today more than 2.5 million Americans are estimated to be affected by mitral regurgitation. This number is expected to double by the year 2030. Every year, 300,000 people worldwide undergo open heart surgery for mitral valve repair, 44,000 people in the US alone. [1]
Flap surgery is a technique essential to plastic and reconstructive surgery. A flap is defined as tissue that can be moved to another site and has its own blood supply. This is in comparison to a skin graft which does not have its own blood supply and relies on vascularization from the recipient site. [2]
A second repair can sometimes be required; causes are recurrence of cancer, new cancer or new trauma. A second flap can be harvested from the contralateral forehead after a prior vertical flap. [1] If an oblique or angled flap was used during the first surgery, the second repair becomes more difficult.
Valve replacement surgery is the replacement of one or more of the heart valves with either an artificial heart valve or a bioprosthesis (homograft from human tissue or xenograft e.g. from pig). It is an alternative to valve repair .
Class IV valves have no more than 0.01% leakage under those conditions; this tends to require multiple graphite piston rings or a single Teflon piston ring, and lapped metal seats. Class V valves leak less than 5 × 10 −12 cubic metres, per second, per bar of pressure differential, per millimetre of port diameter, of water when tested at the ...
The basic working principle of an air-operated double diaphragm pump. Cross-section sketch of diaphragm fuel pump Air-operated double diaphragm pump. A diaphragm pump (also known as a Membrane pump) is a positive displacement pump that uses a combination of the reciprocating action of a rubber, thermoplastic or teflon diaphragm and suitable valves on either side of the diaphragm (check valve ...
Mitral valve repair is mainly used to treat stenosis (narrowing) or regurgitation (leakage) of the mitral valve. [citation needed] A mitral balloon valvuloplasty enlarges the valve opening to allow greater oxygenated blood flow into the left ventricle, and since severe mitral regurgitation can be a major complication, degrees of stenosis, regurgitation, and valve anatomical features are taken ...