Abstract: A pressure transducer has a thin central portion formed of a molded thermoplastic resin. A conductive polymer forms the resistive elements of a Wheatstone bridge printed and baked onto the molded substrate.

Abstract: In a blood pressure monitoring system, a transducer which is a conductive rubber tube having conductive terminals at each end. The terminals are connected to a circuit for detecting changes in resistance of the tube. The internal surface of the tubing is coated with a dielectric material.

Abstract: A system for calibrating a blood pressure transducer and monitor combination. The transducer assembly has a calibration resistor. The monitor cable has a housing which contains a switch and a shunt resistor. Electrical connections are provided to place the calibration resistor and shunt resistor in series with each other and in shunt across one leg of a transducer bridge to produce a reading of 100 mmHg on the monitor.

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: Blood gases and the like are monitored by a single probe having multiple dye wells and dyes immobilized in the wells, the dyes being exposed to the blood gases. Optical fibers and waveguides connected to the dye wells permit light to be directed from a light source to the dyes and the light due to absorption or the spontaneous emission of the dye returned to a light detector. The intensity, phase shift or other mechanism of the returned radiation is a measure of the partial pressure of a respective blood gas.

Abstract: Apparatus for monitoring and regulating intracranial pressure. Primary components are a manometer tube connected to a fluid collector, a transducer for dynamic electronic monitoring, and an automatic regulator. These components are interconnected by tubing and three main stopcocks which permit multiple procedures to be performed. A fourth stopcock, syringe and appropriate connections permit the system to be connected to a dedicated source of sterile liquid.

Abstract: An apparatus for measuring pressure within a conduit is disclosed preferably comprising a tube whose resonant frequency varies with the pressure of fluid within the tube; means for passing the fluid to be measured through the tube; two active piezoelectric films disposed in intimate contact with the tube on opposite sides thereof; first electronic means for energizing the first of the films to cause the tube to resonate at its natural frequency, and second electronic means connected to the other of the films to monitor the frequency of the tube.

Abstract: A pressure infusor for introduction of fluids into the human body. Two sheets of polyurethane overlie each other and are continuously sealed to form an air-inflatable bladder. A strip of polyurethane projects from one vertical margin of the bladder to wrap completely around the liquid-filled bag. A narrow elongated strap is centrally attached to one margin of the infusor and is long enough to wrap completely about the infusor with a bag enclosed. Velcro strips are secured to the strap so that it can be fastened upon itself.

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.

Abstract: A transducer dome for isolating a transducer from the liquid which actuates it. The transducer dome has a hemispherical or conical portion containing a single inlet and a threaded portion for connection to a transducer. The inlet is isolated from the transducer by a diaphragm formed from a hydrophobic bacterial filter, which allows venting of air during priming.