Abstract: An air duct valve arrangement for use ain an air circulation system comprising an air handler unit and an air treatment unit. The valve arrangement being disposed to prevent short-circuiting of the air treatment unit, but not to hinder the operation of the air handler unit.

Abstract: A system for detecting leakage in a device having a fluid-driven membrane inserted in the body, for example, a balloon pump, includes a fluid drive circuit with a moisture remover having a capacity just sufficient to remove water vapor entering the circuit due to intrinsic permeability of the membrane. An in-line humidity sensor responds quickly to an increase in vapor pressure, indicating a leak, and activates a shut-down circuit to prevent leakage of the drive fluid into the body. The system is employed in a balloon pump driven by a pulsating air source.

Abstract: A balloon assembly has an intrinsic curvature adapted to a passage in a blood vessel, and is straightened by a removable stiff member extending within the catheter to facilitate insertion along the passage. When the balloon is at a curved portion of the passage, the stiff member is retracted, allowing the balloon and adjacent support to conform to the curved passage and advance further without trauma to the vessel. The curved balloon may be stably positioned in a curved arterial passage and pumped with a pulsatile inflation source.

Abstract: A set for the passive infusion of one or more medications at a determined rate includes a fluid supply tube having first and second branched flow paths with first and second rate-defining flow restrictors. An injection port upstream of the first flow restrictor permits injection of a drug to be metered, so the first restrictor provides a metered flow of drug plus carrier, and the second restrictor provides a metered flow of diluent/carrier. A Y-connector, which may contain a mixing element, combines the two flows to provide the desired output flow and drug concentration. Further flow branches, each with an injection port and a flow restrictor, allow additional drugs to be metered in other concentrations. A flushable flow restrictor segment includes a flexible flow tube which may be pinched off, and a substantially rigid capillary tube integral with the flexible tube.

Abstract: In an infusion system, a source of pressurized liquid infusate is connected to the upstream end of a small-bore flow restrictor and drives a flow of infusate therethrough; the downstream end of the flow restrictor is connected to the patient. The infusate at the upstream end is in communication with an annulus inflatable by infusate pressure of at least 200 to 500 Torr; the infusate at the downstream end is in communication with another annulus inflatable by infusate pressure of only 35 to 110 Torr, as occurs during infiltration. Inflation of an annulus provides a visible indication and can provide electrical contact for an alarm.