Abstract: A constant pressure generator has a variable volume fluid reservoir formed by a container having fixed walls which cooperate to define a cross-sectional area of the container perpendicular to an axis that varies with location along the axis and an end wall arranged for movement along the axis to vary the volume of the reservoir and which is adapted to conform substantially to the fixed walls of the container to provide the region of variable area substantially that defined by the fixed walls. A force generator is engageable with the variable area region to exert a variable force thereon and the walls are shaped such that the area of the region varies interdependently with the exerted force as the volume varies to maintain the communicated pressure constant.

Abstract: In a method and an arrangement for acoustic determination of an instantaneous fluid temperature, acoustic velocity V in a fluid is monitored and an output signal related to the acoustic velocity is generated. A conventional temperature sensor senses a fluid temperature TS and generates an output signal related thereto.

Abstract: An apparatus for supplying a breathing gas to a patient has a gas supply for generating a flow of breathable gas during an inspiration and an expiration phase of a patient breathing cycle. An inspiration line is provided having an inlet through which a flow of breathing gas from the supply can pass as well as an expiration line through which an expiration gas from the patient can flow. A flow controller is provided for selecting, during an inspiration phase, a first flow path for gas from the supply into the inlet and for selecting, during the expiration phase, a second flow path for gas from the supply in a direction across a venturi outlet of the expiration line, to enhance removal of expiration gas therefrom by venturi suction.

Abstract: In a method and an arrangement for acoustic determination of an instantaneous fluid temperature, acoustic velocity V in a fluid is monitored and an output signal related to the acoustic velocity is generated. A conventional temperature sensor senses a fluid temperature TS and generates an output signal related thereto.

Abstract: An arrangement to provide a moisture barrier and bacteria barrier for various medical components that is connected to a measuring tube, arranged in the flow paths of a respirator is simple and inexpensive and exchangeable and does not cause a flow resistance in the flow paths of the respirator. A carrier carries at least two moisture barriers and bacteria barriers such that one barrier, given a carrier introduced in the respirator, is arranged exactly in front of each component.

Abstract: An ultrasonic flow meter for measuring a flow in a measurement channel has a first sensor chamber with a first membrane arranged against the measurement channel and a first transducer arranged at a specific distance from the first membrane, and a second sensor chamber with a second membrane arranged against the measurement channel and a second transducer arranged at a specific distance from the second membrane is described. The first membrane and the second membrane are gas-tight. In order to reduce loads on the membrane, while still allowing the membrane to be made as thin as possible, the first sensor chamber and the second sensor chamber are gas-tight, a first gas line connects the first sensor chamber to the measurement channel and a second gas line connects the second sensor chamber to the measurement channel.

Abstract: A device for flushing a deadspace during mechanical ventilation of a patient with a ventilator includes a reservoir having a variable volume container, such as a balloon, adapted to receive and hold a portion of the pressurized breathing gas provided by the ventilator during an inspiration phase and to supply, at least during a final part of an expiration phase, the received breathing gas as pressurized flushing gas to a first end of a conduit which is disposed in a patient's airway. The reservoir has an outlet in pressure communication with the first end of the conduit and operable to supply the flushing gas as a result of the pressure at the first end of the conduit falling below that of the gas within the reservoir.

Abstract: A device for repeated registration of the number of thermal cycles to which a part for medical usage has been subjected has a temperature-sensitive element and/or a pressure-sensitive element arranged in conjunction with the part. This element reversibly changes its physical shape with temperature and/or pressure, variations in pressure being invariably associated with changes in temperature. A registration unit registers this change in shape when it exceeds a specific threshold value, as an indication of the part undergoing, or having undergone, a thermal cycle.

Abstract: In a method for determining the elastic volume (representing the gas which must be added to compensate for the compression of gas occurring in the tubing system) of a tubing system connected to a patient without the patient's lungs and airways entering into the determination, a determination of the volume of the tubing system is made at two different pressures during one breathing cycle and the elastic volume is calculated from the volumes thus determined. The volume of the tubing system can be established by adding a predetermined flow of a first gas to the tubing system, while constant pressure is maintained in the tubing system, when the flow of breathing gas to/from the patient is virtually zero, determining when the first gas starts flowing out of the tubing system and determining the volume of the added first gas, this volume constituting the volume of the tubing system.

Abstract: An apparatus panel for placement at least partially in front of a screen or display or over a printed surface, has at least two stacked, transparent panel plates, a mechanical user interface in the form of at least one mechanically actuated regulating arrangement and a corresponding contact arrangement. In order to reduce the risk of leakage into the panel, the panel is devised so that regulating arrangement and the contact arrangement are physically separated by at least one of the panel plates and can sense each other's relative positions and, accordingly, the mechanical user interface's setting, without touching.

Abstract: A valve arrangement includes a variable aperture through which fluid may flow, a closure element adjustable to vary the size of the aperture, and a sensor unit which generates an output signal dependent on the aperture size. The sensor unit has a light detector disposed downstream of the aperture to detect light passed through the aperture and to generate the output signal dependent on the detection of the light. This signal is supplied to a visual display unit having indicators that are respectively activated to show if the valve is open or closed.

Abstract: In a method for detecting a variation, such as a variation in the concentration of a substance, in a flowing medium, a sample of the medium is made to flow past a sensor for detecting the variation, with the direction of flow of the sample being reversed and the velocity of the sample in relation to the sensor being reduced during passage of the sample through the sensor. A device for detecting such a variation contains a sensor and a pump controlled to reverse the direction of flow and to reduce the velocity of the sample of the medium for making a measurement of the sample.

Abstract: In a valve having a mechanically journalled movable element for regulating the valve's degree of opening, and in a method for controlling such a valve, the movable element and journals are made to move in relation to each other in order to reduce friction in the journals of the movable element. The movable element is then in a position governed by the valve's prevailing degree of opening.

Abstract: A ventilator system has an inspiratory line, an inspiratory pressure meter arranged to sense pressure in the inspiratory line, and expiratory line, an expiratory pressure meter arranged to sense pressure in the expiratory line, and a connector device for connecting a patient to the ventilator system. The connector device includes a first gas line connected to the inspiratory line, and a second gas line connected to the expiratory line so that gas will only be able to flow in one direction through the lines. Pressure in the lungs can accordingly be directly measured by the expiratory pressure meter during inspiration and by the inspiratory pressure meter during expiration.

Abstract: An anesthesia system has a fresh gas source for supplying a defined flow of fresh respiratory gas to a respiratory circuit wherein the flow is regulated by a flow valve which is controlled on the basis of a flow measured by a flow meter. The anesthesia system is permits the flow meter to be calibrated while the system is in operation to permit the supply of a continuous, or substantially continuous, flow of fresh respiratory gas to the respiratory circuit.