Abstract: An artificial blood conduit comprises two concentrically associated tubes. Convolutions in the tube walls provide flexibility and reduce the tendency to kink. The inner tube is porous to promote the growth of a stable biological interface. The outer tube is impervious to prevent contamination of the blood in locations external to the host body. Rigid reinforcing rings located between the two tubes and affixed to the outer tube, provide the conduit with strength to resist collapse from a wide variety of stress forces. A Dacron cloth sewn tightly around the exterior of the conduit allows tissue fixation without puncturing the conduit. End connectors are provided for different types of anastomoses.

Abstract: A monitor for a pneumatically driven blood pump receives an input correlated to mechanical operation of the blood pump and electrically transforms the information to clinical information related to such factors as stroke volume of the pump, average stroke volume, flow rate and beat rate.

Abstract: A chromatographic system is provided for detecting in a liquid sample the presence of organic nitrogen containing compounds. A liquid chromatograph separates constituents of the liquid sample and discharges the separated constituents in a timewise distribution. Effluent from the chromatograph is atomized into a converter and there oxidized at a temperature approximately in the range 600.degree. to 800.degree. C for converting the nitrogen in the organic nitrogen containing compound to nitric oxide. Sufficient oxygen is supplied to the converter to fully oxidize the sample introduced therein. Effluent is transferred from the converter to a nitric oxide detector which measures the nitric oxide present in the converted sample and thereby provides a measurement of the organic nitrogen containing compound in the sample.

Abstract: A liquid-gas interface is provided between a heated reaction chamber of an N-nitroso compound detection system and a liquid chromatograph. The liquid-gas interface atomizes liquid chromatograph effluent, including the N-nitroso compounds to be measured, with a stream of carrier gas, into the reaction chamber. In the heated reaction chamber, the effluent from the interface is vaporized. Condensation of non-volatile N-nitroso compounds is avoided by preheating the liquid effluent prior to atomization.

Abstract: A chromatographic system is provided for detecting in a liquid sample the presence of organic nitrogen containing compounds. A liquid chromatograph separates constituents of the liquid sample and discharges the separated constituents in a timewise distribution. Effluent from the chromatograph is atomized into a converter and there oxidized at a temperature approximately in the range 600.degree. to 800.degree. C for converting the nitrogen in the organic nitrogen containing compound to nitric oxide. Sufficient oxygen is supplied to the converter to fully oxidize the sample introduced therein. Effluent is transferred from the converter to a nitric oxide detector which measures the nitric oxide present in the converted sample and thereby provides a measurement of the organic nitrogen containing compound in the sample.

Abstract: A pneumatic pump adapted primarily as a left ventricular heart assist device includes a flexible bladder with a rigid housing. A pneumatic driver applies rhymical pulses between the bladder and the housing to repetitively collapse the bladder and establish a pumping action through the bladder, in conjunction with check valves in the inlet and outlet to the bladder. Between the driver and the pump there is provided a pneumatic pulse limiter which includes a flexible diaphragm isolating the driver from the pump. Pulses from the driver are transmitted to the pump only through the flexible diaphragm and the diaphragm is constrained to move only within established limits. Regardless of the magnitude of the pulse from the driver, the maximum pulse applied to the pump cannot exceed that corresponding to the maximum displacement of the diaphragm.Between successive pulses, the portion of the system between the driver and the flexible diaphragm is depressurized.

Abstract: A pneumatic pump adapted primarily as a left ventricular heart assist device includes a flexible bladder with a rigid housing. A pneumatic driver applies rhythmical pulses between the bladder and the housing to repetitively collapse the bladder and establish a pumping action through the bladder, in conjunction with check valves in the inlet and outlet to the bladder. Between the driver and the pump there is provided a pneumatic pulse limiter which includes a flexible diaphragm isolating the driver from the pump. Pulses from the driver are transmitted to the pump only through the flexible diaphragm and the diaphragm is constrained to move only within established limits. Regardless of the magnitude of the pulse from the driver, the maximum pulse applied to the pump cannot exceed that corresponding to the maximum displacement of the diaphragm.Between successive pulses, the portion of the system between the driver and the flexible diaphragm is depressurized.

Abstract: A water heater has a hot gas conduit forming a heat transfer wall enclosed by a water jacket. A series of baffles within the conduit direct jets of hot gases to impinge upon the heat transfer wall. The baffles thermally expand during operation to engage the heat transfer wall, but are removable as a unit for servicing when the heater is cool.

Abstract: Apparatus for detecting the amount of a specific compound in a sample. The apparatus comprises, in combination, a gas chromatograph, a cold trap and a specific gas detector. The cold trap includes means to cool the gas passing therethrough to a predetermined pressure therein, whereby gaseous effluent from the trap substantially consists of the specific gas and an inert gas.

Abstract: Apparatus for detecting the amount of a specific compound in a sample dissolved in a liquid solvent. The apparatus comprises, in combination, a high pressure liquid chromatograph, means to transform the chromatograph effluent to the gaseous state, a cold trap and a specific gas detector. The cold trap includes means to cool the gas injected therein at a predetermined temperature, and means to maintain a predetermined pressure therein, whereby the solvent is condensed and the gaseous effluent from the trap substantially consists of the specific gas.

Abstract: Apparatus for detecting the amount of a specific compound in a sample. The apparatus comprises, in combination, a gas chromatograph, a cold trap and a specific gas detector. The cold trap includes means to cool the gas passing therethrough to a predetermined temperature, and means to maintain a predetermined pressure therein, whereby the chromatograph carrier gas is condensed and the gaseous effluent from the trap substantially consists of the specific gas.

Abstract: The N-nitroso compound content of a sample is measured by selectively breaking the N-NO bond in the N-nitroso compound molecule by non-catalytic pyrolyzation at temperatures in the range 300.degree. C to 500.degree. C, thereby liberating nitric oxide (NO), and by the subsequent measurement of the amount of nitric oxide liberated. The apparatus comprises a chromatograph and an NO detector together with a non-catalytic pyrolyzer. The pyrolyzer includes a chemically inert material configured to provide a cylindrical cross-section flow path for the chromatograph effluent. The pyrolyzer further includes the temperature control means for adding thermal energy at a controlled rate so that the flow path is characterized by temperatures in the range of 300.degree. C to 500.degree. C.

Abstract: Apparatus for detecting the amount of a specific compound in a sample dissolved in a liquid solvent. The apparatus comprises, in combination, a high pressure liquid chromatograph, means to transform the chromatograph effluent to the gaseous state, a cold trap and a specific gas detector. The cold trap includes means to cool the gas injected therein at a predetermined temperature, and means to maintain a predetermined pressure therein, whereby the solvent is condensed and the gaseous effluent from the trap substantially consists of the specific gas.

Abstract: An expansion mode tidal regenerator heat engine including a housing assembly enclosing an interior region, a power extraction means and a condensable vapor disposed within the interior region. A condenser is adapted to maintain a portion of the interior region at a condenser temperature equal to or below the boiling point of the working fluid at a predetermined minimum pressure. A super-heater is adapted to maintain a portion of the interior region at a super-heater temperature above the boiling point of the working fluid at a predetermined maximum temperature. A boiler is adapted to maintain a portion of the interior region below the super-heater temperature and above or equal to the boiling point of the working fluid at a predetermined maximum pressure.

Abstract: An annular tidal regenerator heat engine including a housing assembly enclosing a cylindrical interior region with a loose-fitting piston and a condensable vapor working fluid disposed therein.A condenser is adapted to maintain a portion of the interior region near one end of the piston at a condenser temperature equal to or below the boiling point of the working fluid at a predetermined minimum pressure. A super-heater is adapted to maintain a portion of the interior region near the other end of the piston at a super-heater temperature above the boiling point of the working fluid at a predetermined maximum pressure. A boiler is adapted to maintain a portion of the cylindrical shell portion of the interior region between the piston and housing at a boiler temperature below the super-heater temperature and above or equal to the boiling point of the working fluid at a predetermined maximum pressure.

Abstract: A spirometer for measurement of both the rate and volume of expiratory breathing, and creating a graphic record of the same. In a preferred embodiment, the spirometer incorporates an expansible chamber of the piston type, fitted with a molded rolling rubber seal. A recording surface in the form of a card is attached to the piston and a pen is moved across the face of the card at a constant velocity as a subject breathes into the expansible chamber. There is obtained a plot of the volume of expiration flow as a function of time. A control system provides for automatic operation.

Abstract: A food cooker is illustrated in the form of a deep-fat fryer, in which the fat is isothermally heated to an operating temperature below a temperature range in which an unacceptably high rate of undesirable decomposition products formation occurs in the cooking liquid. The heat transfer process used in vaporization and condensation of a confined liquid essentially isothermally and substantially at the working temperature. Condensation of the heat transfer vapor takes place at an outer surface of the container for the fat. Heat is applied to the heat transfer liquid remote from the container, which having no heating element or elements intruding into its interior is easy to clean. Heat is transferred to the cooking fat by condensation of the heat transfer vapor essentially only as it is used by the load being cooked. Hot spots are minimized, so that the formation of undesirable decomposition products of the cooking fat is retarded.

Abstract: An optical device for use with laser systems comprising a crystal having a liquid coating. The material comprising the liquid coating is characterized by an index of refraction which is closer to at least one principal index of refraction of the crystal than the index of refraction of the medium exterior to the crystal is to any principal index of refraction of the crystal.

Abstract: A nasotracheal tube holder comprises a substantially straight projection having a laterally curved, trough-like surface mounted on a base for securing said projection to a person's head such that the projection is adapted to receive in longitudinally aligned relation the protruding end of a nasotracheal tube in its applied working position. In a preferred embodiment a pair of laterally opposed tabs at the outer end of the projection serve as stop lugs for preventing a wrapping, such as tape, which binds the tube to the projection from sliding off the projection.

Abstract: A ventible closure for a container adapted to hold sterile fluids wherein the container has a neck with an open end surrounded by a beaded rim. The closure includes a rigid plug which fits down into the container neck and an elastic cap fitting over the open end of the neck in engagement with the rigid plug and the beaded rim to seal the container. For venting, internal pressure within the container causes outward flexing of the elastic cap to break the seal and establish flow paths for the fluid to escape from the container.