Abstract: An apparatus comprising a pressure limiting valve for preventing transmission of elevated pressure to components downstream of the apparatus. Preferably, the pressure limiting valve is used in combination with a flow regulating device that maintains a substantially steady flow rate through the apparatus even when subject to a wide range of applied pressure. The apparatus of the present invention is preferably suitable for use with filter systems wherein the pressure limiting valve is placed upstream of filter components that have limited burst and fatigue life capabilities. By isolating the downstream filter components from pressures that are greater than the target pressure range for a given application, the filter components can be designed to operate at much lower pressure, can be produced at a smaller size, and at a reduced cost.

Abstract: An atherectomy burr has an operating diameter that is larger than the diameter of a catheter in which the burr is routed. The burr may include a polymeric balloon that is coated with an abrasive and that expands when the burr is rotated. Alternatively, the burr may include a polymeric tube that is coated with an abrasive and secured to the proximal end of the burr. When the burr is rotated, the polymeric tube expands by centrifugal force. Alternatively, the burr may comprise a metallic strip wound over a mandrel. When the strip is tightly coiled to the mandrel, its outer diameter decreases. The outer diameter of the burr increases as the metallic strip expands. In addition, the burr can be formed as a wire spring wound over a drive tube. The distal end of the spring is coupled to a nose cone that can move within a distal lumen in the drive tube. The maximum expansion of the burr is controlled by the distance that the nose cone can be retracted into the lumen.

Abstract: An atherectomy burr has an operating diameter that is larger than the diameter of a catheter in which the burr is routed. The burr may include a polymeric balloon that is coated with an abrasive and that expands when the burr is rotated. Alternatively, the burr may include a polymeric tube that is coated with an abrasive and secured to the proximal end of the burr. When the burr is rotated, the polymeric tube expands by centrifugal force. Alternatively, the burr may comprise a metallic strip wound over a mandrel. When the strip is tightly coiled to the mandrel, its outer diameter decreases. The outer diameter of the burr increases as the metallic strip expands. In addition, the burr can be formed as a wire spring wound over a drive tube. The distal end of the spring is coupled to a nose cone that can move within a distal lumen in the drive tube. The maximum expansion of the burr is controlled by the distance that the nose cone can be retracted into the lumen.