Abstract: A double-acting reciprocating motor with a uni-directional fluid flow path comprises a piston disposed within a cylinder. Within the cylinder, the piston defines a first chamber between the piston and a cylinder base and a second chamber between the piston and a cylinder head. Fluid is introduced into the first chamber of the motor through an inlet port associated with the cylinder base. A pass-through valve controls the flow of fluid from the first chamber to the second chamber. An outlet valve regulates the draining of fluid from the second chamber through an outlet port associated with the cylinder head. Fluid pressure within the first chamber urges the piston towards the cylinder head when the pass-through valve is closed and the outlet valve is open. The piston surface facing the second chamber is larger than the piston surface facing the first chamber, so the piston moves towards the cylinder base when the pass-through valve is open and the outlet valve is closed.

Abstract: The injector of the invention serves for applying contrast media for X-ray or nuclear spin tomography and has a tube (3), as well as a roller pump (7) surrounded at least partially in peripheral direction by the tube (3) for transporting the fluid from a storage vessel (2) to a cannula. A pressure chamber (10) connected with the interior of the tube (3) through an opening (9) in the tube wall is provided, which has a component (11) adjustable under the effect of the fluid pressure, acting upon a pressure sensor (12).

Abstract: The catheter assembly includes an expandable member mounted to the distal end of a placement catheter, for delivery of a therapeutic device in one of the branch vessels of a bifurcated vessel. The catheter assembly includes lumens for a tracking guide wire and a positioning guide member for placement of the therapeutic device. The therapeutic device is mounted on the expandable member, the tracking guide wire is placed into the target branch vessel, and the placement catheter is then introduced over the tracking guide wire. A positioning guide member is introduced through the catheter, extended through an exit port in the catheter proximal to the expandable member, and then placed in another branch vessel of the bifurcation. The placement catheter then is advanced until the positioning guide member engages the vessel carina between the branch vessels, and the therapeutic device then may be placed accurately in the target branch vessel.

Abstract: An oil free screw compressor includes a compressor main body directly connected to a high speed motor via a drive side gear and a driven side gear having a uniform speed ratio. A bearing in a side of the high speed motor employs one having the same size as that of a bearing in a side of the compressor main body. The same material as a viscous seal provided at both end portions of a male rotor and a female rotor is used for a viscous seal provided at both end portions of a motor shaft. The high speed motor is driven by a high frequency type inverter. The electric motor side and the compressor main body side are made in a rotational shaft structure which is dummy symmetrical about a uniform gear portion.