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2nd Generation EVR Valve

The EVR valve is a transcatheter aortic bioprosthesis that features a self-expanding nitinol frame. This new valve has a cylindrical shape of the lower part and sutured leaflets made from porcine pericardium. This new generation of valve has improved radial force and a seal skirt that is slightly cranial to the native annulus. This design helps prevent deep valve deployment, and also has a smaller delivery profile. This new design has also reduced the incidence of paravalvular leaks.

The 2nd generation EVR valve has a new delivery system that is easier to handle and less expensive to produce. The injection molding process completely encloses the solenoid assembly. This design eliminates the need for cumbersome calibration requirements and allows for greater flexibility. Its streamlined range and ease of wiring make the valve suitable for various applications.

The EVR chamber 82 is a circular-shaped cavity defined by the inner diameter of the lower connecting flange 78 of the solenoid housing 72. This cavity is positioned below the armature 46. The EVR chamber 82 selectively communicates with the air inlet 38 through the central bore 36. This air passageway permits axial movement. The armature 46 is then urged by atmospheric air to “open” the valve position. This is accomplished by lifting the armature 46 by a magnetic fluid that is generated below 30% duty cycle. The output flow is non-linear below 30% duty cycle.

A preloaded armature bias spring is a common design in conventional flow regulators. The evr valve coil spring 160 presses the diaphragm valve assembly 92 downward. The resulting angular preload enables the valve assembly to achieve its sizing, or net build, configuration. The preload can be adjusted by rotating the calibration screw, which is fixed to the spring retainer acting on the coil spring. This calibration screw is threaded into the threaded aperture in the housing portion of the second valve.

An orifice 105 is incorporated into the bottom of the external cavity 80. This orifice enables a balanced vacuum to be maintained within the control chamber 90. The vacuum input at connector 98 is controlled by an electrical signal from the ECU 22. The reference chamber 108 is sized to provide a portion of the restrictive flow needed to balance the vacuum pressure.

The EVR prosthesis is available in two sizes. The smaller size is intended for patients with narrower femoral arteries. The larger size is meant for patients with wider arteries. In addition, the EVR prosthesis features an option to recapture the valve during deployment, which may prevent the occurrence of suboptimal valve deployment. This feature was adopted due to the deep position of the prosthesis in the left ventricular outflow tract.

The EVR prosthesis has a higher average implantation depth at the non-coronary cusp (4.0 mm), compared to the CV prosthesis. The new generation of valve has a larger sealing skirt that is able to capture more fuel vapors than the previous generation.

The EVR valve is a versatile platform that offers the highest level of quality and reliability. It is designed to stand up to high temperatures and can handle refrigerants with GWPs as low as R290 propane. The EVR valve platform is compatible with other systems, such as hot gas bypass and cold gas bypass, and is compatible with cooling capacities of 0.3 to 65 kW.