Abstract: A method for performing a percutaneous valve bypass, the method comprising providing a bypass conduit having a first end and a second end; connecting the first end of the bypass conduit to a first vascular structure at a first anastomosis; connecting the second end of the bypass conduit to a second vascular structure at a second anastomosis; advancing a percutaneous valve along the bypass conduit to a deployment site located within the bypass conduit; and deploying the percutaneous valve at the deployment site so that fluid is permitted to pass from the second vascular structure to the first vascular structure but is prevented from passing from the first vascular structure to the second vascular structure.

Abstract: A method for performing a percutaneous valve bypass, the method comprising: providing a bypass conduit having a first end and a second end; connecting the first end of the bypass conduit to a first vascular structure at a first anastomosis; connecting the second end of the bypass conduit to a second vascular structure at a second anastomosis; advancing a percutaneous valve along the bypass conduit to a deployment site located within the bypass conduit; and deploying the percutaneous valve at the deployment site so that fluid is permitted to pass from the second vascular structure to the first vascular structure but is prevented from passing from the first vascular structure to the second vascular structure.

Abstract: Vacuum pumping apparatus includes a pump frame, a stationary scroll element secured to the pump frame, the stationary scroll element including a stationary scroll blade, an orbiting scroll element including an orbiting scroll blade intermeshed with the stationary scroll blade, a motor secured to the pump frame, and a crankshaft coupled between the motor and the orbiting scroll element for producing orbiting movement of the orbiting scroll blade relative to the stationary scroll blade when the motor is energized. The crankshaft includes a first component having a first coefficient of thermal expansion and a second component having a second coefficient of thermal expansion.

Abstract: A vacuum pumping system includes a primary vacuum pump having an inlet for coupling to a system, and a secondary vacuum pump having an inlet coupled to the exhaust of the primary vacuum pump. The primary vacuum pump is an oil-free, positive displacement vacuum pump having multiple clearance seals between the inlet and the exhaust. The primary vacuum pump may be a scroll vacuum pump, and the secondary vacuum pump may be an oil-free diaphragm pump. The system may include a valve coupled to the exhaust of the primary vacuum pump and configured to couple the exhaust of the primary vacuum pump to an interpump exhaust in response to a selected condition, such as the pressure level at the exhaust of the primary vacuum pump.

Abstract: Scroll pumping apparatus includes a first scroll element and a second scroll element, a drive mechanism operatively coupled to the second scroll element for producing orbiting motion of the second scroll element relative to the first scroll element, and a synchronization device including a strip having connected, substantially flat sections, coupled between the first scroll element and the second scroll element. The synchronization device may have a generally square configuration.

Abstract: A compact scroll pump includes a scroll set having an inlet and an outlet, and a drive mechanism. The scroll set includes a stationary scroll blade extending from a stationary plate and an orbiting scroll blade extending from an orbiting plate. The stationary and orbiting scroll blades are intermeshed together to define one or more interblade pockets. The orbiting scroll blade is located on a first side of the orbiting plate, and the drive mechanism is operatively coupled to a second side of the orbiting plate for producing orbiting motion of the orbiting scroll blade relative to the stationary scroll blade. The drive mechanism includes a motor and a crankshaft having an axis of rotation, and an orbiting bearing coupled between the crankshaft and the orbiting plate. The scroll set is configured such that an imaginary plane perpendicular to the axis of rotation passes through the orbiting bearing and at least a portion of the orbiting scroll blade.

Abstract: Vacuum pumping apparatus includes a scroll set having an inlet and an outlet, the scroll set including a stationary scroll element and an orbiting scroll element, and a drive mechanism for producing orbiting motion of the orbiting scroll element relative to the stationary scroll element. The vacuum pumping apparatus further includes a bellows assembly coupled between a first stationary component of the apparatus and the orbiting scroll element so as to isolate a first volume inside the bellows assembly and a second volume outside the bellows assembly. One end of the bellows assembly is free to rotate during motion of the orbiting scroll element. The apparatus also includes a synchronization mechanism coupled between the orbiting scroll element and a second stationary component of the apparatus. The synchronization mechanism is located within the first volume.

Abstract: A positive displacement fluid handling apparatus has a first, high volumetric displacement rate scroll pump of nested interacting pairs of fixed and movable spiral-shaped blades supported in a housing between an inlet and an outlet. Each adjacent blade pair is of sufficient angular extent, preferably only about 360.degree., to close an inter-blade pocket. In a preferred form for a vacuum pump, a second scroll pump mounted in the housing has its fluid inlet in direct fluid communication with the first scroll outlet. The second scroll has a single pair of co-acting fixed and movable blades with multiple revolutions with a relatively short axial height. The low back leakage of this second pump allows the first pump to omit tip seals on the free spiral edges of the blades. The volumetric displacement rate of the first pump exceeds that of the second pump. An orbiting plate carries the movable blades of both scroll pumps.