Abstract: A nebulizer apparatus to atomize liquid solutions or suspensions. The nebulizer is typically used in conjunction with a breathing circuit to deliver atomized medicine to a patient. A housing with an opening covered by a thin mesh plate is supplied with the liquid to be nebulized on an “on-demand” basis. The mesh plate or liquid is vibrated at ultrasonic frequencies to atomize the liquid as it passes through the plate into breathing gases flowing through the breathing tube.

Abstract: A method for non-invasively determining functional cardiac output (FCO) and/or venous blood CO2 partial pressure (PvCO2). The amount of CO2 (VCO2N) released from the blood and end capillary blood CO2 content (CcCO2N) are determined from measurements from exhaled breathing gases. The CO2 content of the breathing gases inhaled by the subject is increased and values for VCO2R and CcCO2R are obtained. A regression analysis is performed using the obtained VCO2N, VO2R, CcCO2N, and CcCO2R values. The regression line is extrapolated to obtain a value for CcCO2 when (VCO2) is zero so that CvCO2 becomes known. The CvCO2 thus determined can be inserted in a non-differential form in the Fick equation, along with VCO2 and CcCO2 values from normal breathing, to determine FCO. To determine PvCO2, CvCO2 is altered in accordance with the amount of oxygen in the venous blood, to correctly indicate PvCO2.

Abstract: A method for purging an undesired fluid, such as NO2, from a fluid gas administration system, such as an NO gas administration system. In normal operation, the system supplies NO to the patient with the breathing gases inspired during the inspiration phase of the respiratory cycle. Breathing gases are expired during the expiration phase of the respiratory cycle. In the method, the expiration phase of the patient's respiratory cycle is sensed and the administration system is operated in the expiration phase to pass NO through the system to flush out the system, including any NO2 present, into the expired breathing gases of the patient. Since the contents of the system are discharged during the expiration phase, the NO2 gas so removed is carried away from the patient with the expired breathing gases.

Abstract: A method and apparatus for determining a state of zero gas flow in a conduit, the zero flow state occurring between a first period in which gas flows in one direction in the conduit and a subsequent, second period in which gas flows in the opposite direction in the conduit. A first signal responsive to gas flow in the conduit is obtained. The first signal has one polarity when the gas flow is in one direction in the conduit and the opposite polarity when the gas flow is in the opposite direction. A second signal responsive to the gas flow in the conduit is also obtained. The second signal has the same polarity for either direction of gas flow in the conduit. The derivatives of the first and second signals are taken at successive points in time to determine when the signs of the derivatives of the first and second signals are present in a first predetermined combination of signs.

Abstract: An apparatus/method for detecting an empty breathing gas compartment condition in a bellows ventilator for a patient. The apparatus includes a first sensor for measuring, during inspiration, the incoming flow of gas into a driving gas compartment located in the bellows container. The second sensor measures the pressure in the driving gas compartment. During the inspiration cycle, measurements taken by the first and second sensors are signaled to a control unit and used to determine a .DELTA.V/.DELTA.p compliance value. The compliance value will be large if the bellows is movable, i.e. not in the empty breathing compartment gas condition. The compliance value is small if the empty breathing gas compartment condition exists. The compliance value, so determined, is compared with a reference compliance value in the control unit to detect the empty breathing gas compartment condition.

Abstract: The invention relates to a ventilator for intensified breathing, whereby a restrictor valve for an over-pressure in the system, a valve allowing breathing from the atmosphere and a directional valve for inhalation are combined to provide a single safety valve (21) arranged in a gas mixture and inhalation conduit assembly (7, 8), said safety valve being arranged to be controlled by an electric control system (26) of the ventilator. The invention also relates to a valve of the above type.

Abstract: A method for determining pulmonary functional residual capacity (FRC). A given amount of indicator gas is delivered into the breathing gases flowing into the lungs of a subject in a selected number of sequential breaths. The amounts of indicator gas delivered during the selected number of breaths are summed to provide a cumulative total (.SIGMA.V.sub.in). The amount of indicator gas exhaled in the number of sequential breaths is summed to provide a cumulative total (.SIGMA.V.sub.out). An indication of the concentration of indicator gas in the lungs of the subject (F.sub.ET) is obtained for said two or more breaths. Using the quantities (.SIGMA.V.sub.in), (.SIGMA.V.sub.out), and (F.sub.ET) as measured variables, at least two measured value data sets are formed in which the product of the indicator gas concentration (F.sub.ET) and a regression coefficient comprising the functional residual capacity (FRC) plus the product of the cumulative total of exhaled indicator gas (.SIGMA.V.sub.

Abstract: A medical dosing device/method for providing small discrete volumes of gas, for example sulfur hexa fluoride or nitric oxide, to the breathing gases of a patient. The device includes a charging valve interposed between a gas supply and a dosing chamber. A discharge valve is connected between the dosing chamber and an outlet of the device. The dosing chamber has a pressure sensor connected to a control means for the valves. In operation, the control means closes the discharge valve and opens the charging valve until a predetermined pressure is sensed in the dosing chamber. The charging valve is closed and thereafter the discharge valve is opened to supply gas from the dosing chamber until the pressure sensed by the pressure sensor falls to a second, lower level. The discharge valve is then closed. The gas so discharged forms the volume of gas.

Abstract: A variable orifice pulse valve has a small internal volume for providing small, accurately measured pulse volumes of gas. The valve may be employed to supply a very small quantity of a therapeutic gas or a diagnostic gas into the breathing gases of a patient. The valve has a housing with an inlet for receiving the gas and an outlet providing the pulsatile discharge of the gas. A chamber, formed in the housing, has a first opening in fluid communication with the inlet and a second opening in fluid communication with the outlet. The intermediate chamber is formed to have a small volume compared to the minimum pulsatile gas discharge volume of the valve. A spring biases a variable orifice member toward the first opening and a solenoid moves the variable orifice member away from the first opening to form an orifice that meters a dose of gas into the valve. A sealing member is spring biased into sealing engagement with the second opening.

Abstract: The invention relates to a method and apparatus for metering to a patient an anaesthetic vaporized from anaesthetic liquid held in a liquid space (27) of a liquid container (18) into a gas space (28). The anaesthetic dose contained in a gas flow supplied to a patient is determined and the dose is adjusted in a manner that the dosage of anaesthetic in a gas intended to be respired by a patient matches a desired dosage and the dosage adjustment of anaesthetic contained in a gas supplied to a patient is effected automatically whenever the current dosage differs from a desired value.

Abstract: A ventilator for intensified breathing that includes a single safety valve arranged in the gas mixture and inhalation conduit assembly. The single safety valve includes a restrictor valve for overpressure in the breathing system, a valve that allows breathing from the atmosphere, and a directional valve for inhalation. The safety valve is arranged and controlled by an electronic control system of the ventilator.

Abstract: A special gas dose delivery unit for respiratory equipment has a special gas flow conduit connected to a special gas source. The unit includes a supply of carrier gas for the special gas, preferably obtained by withdrawing gas from the inspiration limb of the patient breathing circuit. A valve, controllable in accordance with desired special gas dose parameters and the breathing pattern of the patient, injects the special gas into the carrier gas for provision to the outlet conduit of the special gas dose delivery unit. The outlet conduit is connected to the patient limb of the breathing circuit for delivery to the patient.

Abstract: An arrangement for preventing overfill of an anaesthetic liquid container of a vaporizer resulting from inclination, comprising a bent intermediate container for guiding anaesthetic liquid to the anaesthetic liquid container for vaporization and for removing a volume of gas equivalent to the filling of anaesthetic liquid from the anaesthetic liquid container. The intermediate container is arranged to form a common conduit for the anaesthetic liquid and the gas removed from the container, and to combine the liquid flow outlet level and the gas flow outlet level in such a way that the anaesthetic liquid is allowed to flow into the anaesthetic liquid container only when the liquid flow outlet level is below the gas flow outlet level. The bent intermediate container may be located interiorly of, or exterior to, the anaesthetic liquid container.

Abstract: A method and an arrangement in connection with vaporizing an anaesthetic, in which an anaesthetic, vaporized in a vaporizer is mixed with fresh gas and delivered to be inhaled by a patient. In order to achieve a reliable operation, the prevailing ambient air pressure is measured, the measured air pressure is compared with a reference pressure and when the prevailing ambient air pressure deviates from the reference pressure, the anaesthetic agent concentration of the fresh gas/anaesthetic mixture to be passed to the patient is adjusted in relation to the variation in the ambient external air pressure.

Abstract: A method and an assembly for filling an anesthetic evaporator, comprises a filling device (1) connectable to a transport container (15) and having a filling head (2) which can be inserted in an attachment point (4) included in an evaporator (3), the filling device and evaporator being provided with conduits (5a, 5b, 6a, 6b) for passing an anesthetic and a substituting gas between the transport container and the evaporator and the assembly comprising a clamping implement (7) for tightening the filling head (2) against a packing surface of the conduits arriving in the attachment point (4) included in the evaporator and a valve element (8, 9), adapted to open and thus to allow a flow of the anesthetic and the substituting gas.

Abstract: An arrangement in connection with an anaesthetic liquid container, comprising a connector with the help of which an anaesthetic liquid container and a transport or supply container of anaesthetic liquid can be connected to one another for guiding the anaesthetic liquid from the transport or supply container to the anaesthetic liquid container and for removing a volume of gas equivalent to the anaesthetic liquid from the anaesthetic liquid container to the transport or supply container. In order to provide a reliable and tight connection, the connector comprises a conduit arrangement which, when connecting the anaesthetic liquid container and the transport or supply container to one another, is adapted to open first a flow connection exclusively to gas.

Abstract: An arrangement in connection with a gas mixer, which is arranged to form a mixed gas of oxygen and another gas to be mixed with it. To provide a simple and reliable arrangement, before the mixed gas is formed the oxygen is arranged to be supplied through both a mechanical adjusting means, and a mechanical and electronic flow-measuring means. The other gas to be mixed with oxygen is arranged to flow through an electronic flow-measuring device. The flow of the other gas is arranged to be regulated by means of an electronically controlled regulating valve, whereupon the electronic flow-measuring means, the electronic flow-measuring device, and the electronically controlled regulating valve are arranged to be operated by means of a control unit.

Abstract: The invention relates to a method and apparatus for metering to a patient an anaesthetic vaporized from anaesthetic liquid held in a liquid space (27) of a liquid container (18) into a gas space (28). The anaesthetic dose contained in a gas flow supplied to a patient is determined and the dose is adjusted in a manner that the dosage of anaesthetic in a gas intended to be respired by a patient matches a desired dosage and the dosage adjustment of anaesthetic contained in a gas supplied to a patient is effected automatically whenever the current dosage differs from a desired value.

Abstract: The invention relates to an arrangement for overfill protection of a container for anaesthetic liquid, comprising a liquid conduit for supplying anaesthetic liquid to a container for vaporization, and a gas conduit for withdrawing a volume of gas equivalent to the filling of anaesthetic liquid from the container. To prevent overfilling of the container, the liquid conduit from a feed point for anaesthetic liquid to the container comprises an inclined duct portion having an inlet through which the anaesthetic liquid is passed to the inclined duct portion and an outlet through which the anaesthetic liquid is passed out from the duct portion and further to the container. A body is positioned in the inclined duct portion such that said body can move in the inclined duct portion from a first position to a second position and vice versa, depending on the inclined position of the container, said body being adapted to move in front of the outlet when the container is tilted and to shut the outlet.

Abstract: An arrangement for filling an anaesthetic vaporiser, the arrangement comprising a filling device to be connected to a transport package for an anaesthetic agent, the filling head of the device being attachable to an opening in the vaporiser. The arrangement comprises a fastening means for clamping the filling head against the sealing surface of conduits leading to the opening, and a valve means arranged to open when the filling head is in the clamped position against the sealing surface of the conduits leading to the opening and thus arranged to allow the flow of the anaesthetic agent between the vaporiser and the transport package and the flow of the substitute gas in the opposite direction between the transport package and the vaporiser.