Abstract: A device for controlling the flow of liquid to a catheter. Two end caps support a capillary tube that provides continuous flow of liquid from one end cap to the other. A flexible, resilient sleeve is connected at its ends to said end caps and surrounds said capillary tube. Said sleeve, when pulled away from said capillary tube, provides an alternate high flow volume flow from one end cap to the other outside of the tube.

Abstract: A blood pressure monitoring system in which an intravascular catheter is connected through flexible tubing to a transducer. The tubing between the catheter and the transducer is filled with physiological solution supplied from a bag under pressure of approximately 300 mm. of mercury. The supply line from the bag to the tube is in series with a capillary so that after the system is filled with the physiological solution, the capillary passes fluid from the supply to the catheter at the rate of around two to seven cc. per hour. Provision is made for bypassing the capillary for the purpose of fast flushing the system as would occur when the system is initially filled with fluid. The fast flush line consists of a plug in series with the line from the supply, the plug having upstream and downstream longitudinal grooves separated by a central collar. A flexible tube surrounds the plug and blocks passage from the upstream and downstream groove past the collar.

Abstract: A two-piece swivel coupling for a catheter system having Luer connections on either end of the coupling. One piece has a recess which receives an O-ring and the other piece has a spigot which projects through the O-ring into a recess. The O-ring provides radial, fluid-tight interference between the spigot and the recess. Means are provided for preventing the pieces from axially compressing the O-ring so that one piece is freely rotatable with respect to the other as the catheter is inserted in a blood vessel through a tortuous path into a patient's heart.