Abstract: A heating device, usable in an oven for heating chromatographic equipment, includes an intake for passing an air flow produced by an air supply connected thereto into a cavity formed inside of a tubular member. A heating element, preferably located within that cavity, heats the air flow to an elevated temperature as well as the walls of the tubular member. A heater housing having an enclosed volume contains the tubular member. The heated air flow passes from the cavity into the enclosed volume where it is distributed along both the interior surfaces that define the enclosed volume and the outside of the walls of the tubular member. The interior surfaces are thereby heated while the heated air flow receives further heat from the heated cavity walls. A manifold including an elongated portion having a plurality of apertures formed therethrough with integral nozzles is connected to the heater housing for receiving therefrom the heated air flow.

Abstract: A solenoid operated drive system or actuating unit for driving blood pumps such as intra-arterial "balloon" pumps, implantable pulsatile pumps, external pumps and the like, wherein a shaft attached to the movable end of a bellows is caused to move back and forth by a pair of oppositely disposed solenoids. The extent of the excursion of the shaft and hence the movable end of the bellows is variably controlled by a first stopper fixedly attached to the frame and a second stopper fixedly attached to a carriage which is adjustably carried within the frame. The solenoids are alternately actuated and/or controlled by suitable control signals which are keyed to the heartbeat or R wave. At the beginning of each cycle for each solenoid and for a short time thereafter, depending on the cycle, a voltage is applied to provide maximum drive.