Medical Graphics Corporation

Other

A Gerrit Crawford

John A Norlien

Michael G Snow

James M Huhn

Kurt J Michler

Douglas C Morrison

A drying sample line for coupling a patient's expiratory gases to a gas analyzer consists of first and second concentrically disposed tubes where the innermost tube is fabricated from Nafion plastic. The expiratory gas is drawn through the lumen of the Nafion inner tube and, simultaneously, dried air is made to pass through the lumen of the outer tube in a counterflow direction relative to the expiratory gases. Because of the properties of the Nafion plastic, water vapor (moisture) contained in the expiratory gas being coupled to the analyzer passes through the wall of the Nafion tube and into the dried air stream. In this fashion, the water vapor is removed from the expiratory gas mixture being applied to the analyzer.

Drying sample line

A flow meter system having a disposable mouthpiece including symmetrically disposed pitot tubes for measuring the velocity of the respiratory gases flowing through the mouthpiece and an electronic module including sensitive pressure transducers coupled to the mouthpiece and operative over a wide dynamic range provides input signals to a signal processing network for converting the pressure readings to flow information useful in cardiopulmonary performance analyzing equipment.

Flow meter system

A zirconia oxygen sensor is disclosed which is especially designed for sensing respiratory gases on a breath-by-breath basis. In order to obtain a sufficiently high response time necessary for breath-by-breath gas analysis, a commercially-available zirconia ceramic element is dimensionally tailored to cooperate with a manifold member such that the volume of the gas being analyzed is extremely small, yet uniformly distributed over an internal surface of the zirconia cell. Cooperating with the zirconia cell and the manifold are a set of spring contacts which perform the dual function of providing an electrical terminal and acting as a gas-type seal when the manifold is compressed against the end of the cell.

Zirconia cell O.sub.2 sensor for respiratory gas analysis

A cold-cathode gas discharge device is coupled between a gas sample inlet and a high vacuum and includes spaced-apart electrodes which, when coupled across a high voltage DC power supply, causes a glow-discharge to be set up within the device with the intensity of the emitted light being proportional to the percentage of a given gas contained within a gas mixture introduced through the sampling inlet. In accordance with the present invention, the glow-discharge device contains a tubular pathway which is bent at a point intermediate the spaced electrodes so that they are not co-linear along the tubular path. A photodetector is sighted coaxially with the downstream leg of the bent pathway and, as such, senses the light emitted in a longitudinal direction rather than in a transverse direction. As such, errors due to fogging of the pathway over time by electrode material or the like and movement of the cathode dark-spaced and Faraday dark-space within the tube do not alter the measurable radiation.

Gas analyzer apparatus

The present invention is a lightweight high pressure tubular storage system for storing and transporting a gas which includes a tubular member being formed from a metallic or composite material and having an opening in the first end and preferably an opening in the second end. The storage system also includes an inlet valve for bringing a cryogenic fluid into the tubular member wherein the preferred inlet valve is a high pressure ball valve which is fluidly coupled to the first end and an outlet valve for regulating the flow of a compressed gas from the tubular member. The outlet valve is an ambient pressure balanced piston-type valve which has a needle valve shut-off mechanism for positively shutting off the flow of the compressed gas and which is preferably fluidly coupled to the second end whereby the cryogenic fluid which is introduced through the inlet valve is contained and allowed to warm up within the tubular member and change into the compressed gas. The outlet valve also has a flow limiting inlet orifice which is fluidly coupled to the second end of the tubular member. The ambient pressure is sensed by means of a fluid filled passage in which the fluid is retained by an elastomeric diaphragm. The present invention is also a method of filling a storage system with a cryogenic liquid at a temperature below the boiling point of the cryogenic fluid and enclosing the cryogenic liquid so that it can warm up to a temperature above its critical temperature in order to change into a compressed gas.

Lightweight high pressure tubular storage system for compressed gas and

The present invention is a bladder-type syringe which a user employs to collect blood samples or deliver prefilled medications or function as a passive indicator of balloon or cuff inflation on balloon-tipped catheter or endotracheal tubes. The bladder-type syringe includes an elongated bladder and a hypodermic needle. The elongated bladder is formed out of a high gas-diffusion barrier film and has an open end and a closed end. The hypodermic needle, which the user employs to penetrate into a blood vessel, has a sharp distal end and a blunt proximal end. A coupling device fixedly, but detachably, and fluidly couples the elongated bladder at its open end to the hypodermic needle at its blunt proximal end which extends into the coupling device to reduce its dead space. The bladder-type syringe also includes an elongated member having a first end and a second end and also having a flat surface with a keeper slot at its first end. The elongated bladder is fixedly, but detachably, coupled to the keeper slot. The user is able to support the elongated bladder and isolate any air bubbles contained in the elongated bladder. The coupling device is mechanically coupled to the elongated member at its second end so that the elongated bladder is suspended above the flat surface of the elongated member. The elongated bladder has longitudinal convolutions whereby the amount of gas contained within the elongated bladder is minimized when the elongated bladder is empty.

Growing community of inventors

San Francisco, CA, United States of America

A Gerrit Crawford