Abstract: A multi-layered balloon is provided where each layer is formed such that each layer is made from tubing that optimizes the inner wall stretch thus providing maximum balloon strength. The high pressure, multi-layer balloon is provided with layers that allow for slipping, such that the balloon has a very high pressure rating and toughness, yet excellent folding characteristics. Methods for producing such multi-layer balloons using existing balloon forming equipment are also provided. The multi-layer balloons can have alternating structural and lubricating layers, or layers with low-friction surfaces. The multi-layer balloons are preferably manufactured using a variety of methods including nesting, co-extrusion, or a combination of nesting and co-extrusion. The multi-layer balloons have balloon layers having substantially similar, or the same, high degree of biaxial orientation of their polymer molecules such that each balloon layer of the multi-layer balloon will fail at approximately the same applied pressure.

Abstract: A flow meter including a variable area obstruction which is mounted in a conduit. Inputs to a differential pressure transducer are positioned in the conduit on opposite sides of the obstruction to measure fluid pressure differential across the obstruction. In one embodiment, a sleeve is secured within the conduit thereof substantially separated from the conduit so as to prevent fluid condensation on the sleeve, and to create a dead end pocket between the conduit and the sleeve for collecting liquids from the conduit end preventing them from contacting the obstruction. The variable area obstruction comprises an elastic membrane that includes first, second and third leaves which extend into the flow stream and are compliant to fluid flow so that an increase in flow rate increases the deflection of the leaves and increases the through flow area through the obstruction.

Abstract: A variable gas flow meter for obtaining a differential pressure across a membrane having a variable area orifice. The orifice is defined by a hinged flap which swings open in the direction of gas flow. The area of the orifice enlarges with increased flow. The flow meter retains the membrane in a central housing configured to prevent the accumulation of liquids, such as moisture or mucus, which enter the line. In a first, horizontal embodiment, the housing invert is continuous and flush throughout except for a negligible ridge of membrane that remains when the orifice opens. In a second, vertical embodiment, the housing allows liquids in an upper conduit section to drop downward and flow out the device into a lower conduit section through the forces of gravity and a gas flow.

Abstract: A flow meter including a variable area obstruction which is mounted in a conduit. Inputs to a differential pressure transducer are positioned in the conduit on opposite sides of the obstruction to measure fluid pressure differential across the obstruction. In one embodiment, a sleeve is secured within the conduit thereof substantially separated from the conduit so as to prevent fluid condensation on the sleeve, and to create a dead end pocket between the conduit and the sleeve for collecting liquids from the conduit end preventing them from contacting the obstruction. The variable area obstruction comprises an elastic membrane that includes first, second and third leaves which extend into the flow stream and are compliant to fluid flow so that an increase in flow rate increases the deflection of the leaves and increases the through flow area through the obstruction.