Abstract: A valve for regulating a gas flow has a valve seat and a valve body, movable against the valve seat. The valve achieves high accuracy, a wide dynamic range and high operating reliability by causing the valve body substantially only to move axially against the valve seat and by using a stepper motor to actuate the valve body's axial movement against the valve seat with a non-linearly threaded engagement between the stepper motor and valve body so that the valve body performs continuous, non-linear, axial movement against the valve seat.

Abstract: An anaesthetic machine has a gas flow system with a variable-volume gas container for breathing gas, a fresh gas system for supplying the fresh gas system with a flow of fresh gas and a control unit. The control unit controls the variable-volume gas container during a first phase of inspiration so that a flow of breathing gas is released and mixes with a flow of fresh gas from the fresh gas system. The control unit starts a second phase of inspiration if the flow of breathing gas from the variable-volume gas container ceases before inspiration has been completed. The control unit controls the anaesthetic machine during said second phase so that inspiration is maintained with a flow of fresh gas from the fresh gas system in order to achieve a system in which all breathing modes can be accommodated and gas consumption is minimized.

Abstract: A fluid pressure relief valve has an aperture for the flow through of a fluid, the aperture being disposed between a fluid inlet and a fluid outlet. A movably mounted valve element is disposed for pressure communication with the fluid and is movable to unseal the aperture when an opening force exerted by the communicated fluid pressure on the valve element exceeds a counteracting threshold force. A biasing source provides a bias force for moving the valve element toward sealing the aperture. The valve element is disposed for pressure communication with the fluid such that a closing force less than and counter to the opening force is additionally exerted on the valve element by the communicated fluid pressure. This force in combination with the bias force generates the threshold force.

Abstract: A fluid flow meter has a semi-conducting substrate and a number of integral flexible tines orientated across an aperture in the substrate to deflect in the direction of the fluid flow by an amount dependent on that fluid flow. Piezo-resistive regions are included on the respective tines to provide them with electrical characteristics which vary dependent on the degree of deflection. A monitor, operably coupled to the regions of the tines, is provided to monitor the changes in their electrical characteristics and to calculate the flow therefrom.

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 user interface for a medical apparatus has a screen, a memory containing normal data for at least two parameters, a signal input for receiving signal data for the parameters, and a control unit which processes the normal data and the signal data and generates a representation thereof on the screen. The control unit represents the signal data for each parameter in the form of a sector in a regular polygon, compares the signal data to the normal data and varies the appearance of the sector according to the results of the comparison.

Abstract: An interface unit for an electrophysiology measurement system has a number of externally accessible electrical connectors, each connector for releasably mating with one of a number of wires from a combination of catheter-mounted sensors. A fixed configuration connector is provided in a fixed coupling to the connectors and is couplable to an electrophysiology monitoring system. The unit further has a signal generator, such as a suitably programmed EEPROM in combination with appropriate electrical circuitry mounted on an internally located printed circuit board, which generates an output signal containing information particular to and originating from the unit for use by the electrophysiology monitoring system.

Abstract: An anesthetic apparatus has a control unit and a breathing circuit with a connector for fresh gas, a bellows system and an outlet valve. The anesthetic apparatus operates at least as an open system, the connector then constituting an inspiratory part of the breathing circuit and the bellows system and outlet valve constituting an expiratory part of the breathing circuit. In order to reduce the adverse impact of compressible volume in the expiratory section on the functioning of the anesthetic apparatus, the control unit regulates the bellows system during inspiration so that a counter pressure, largely corresponding to the pressure of fresh gas at the connector, is maintained in the expiratory section of the breathing circuit.

Abstract: In method and device for correlating digital signals, a correlation is determined a number of times between bit values of a pulse train input signal and bit values which define a number of leading and/or trailing edges of pulses of a reference pulse train. Each time the relative location of the two sets of bit values is effectively displaced by one bit. A correlator for this purpose (DC) has a number of parallel comparators, each for receiving and holding in a memory a different segment of the input pulse train. Each comparator is configured to calculate a correlation value at a bit location by varying a correlation value at the immediately preceding bit location which is held in a counter dependent on the bit values of the input pulse train corresponding to the ends and center of the associated defined pulse edge at the immediately preceding location.

Abstract: An x-ray examination positioner has a base and an arm whose first end is rotatable around a first axle attached in the base and whose second end is connected to a holder in which a curved carrier is displaceably arranged. One end of the carrier carries an x-ray tube and the other end thereof carries an x-ray these being directed toward one another. In combination with an examination table, the carrier can be brought from a head-placed attitude into a vertical side attitude and/or into a lateral position while retaining the imaginary isocenter and, moreover, the physician has very good access to the patient, by rotatably attaching the holder of the carrier to the arm via a second axle. The first axle and the second axle are oriented such that respective imaginary extensions thereof as well as the central ray between the x-ray tube and the receptor intersect at a common point in all attitudes of the arm and of the carrier.

Abstract: A method and apparatus for determining a pulmonary function parameter, EVG, indicative of a living subject's effective lung volume, namely the lung volume in which gas exchange between respiratory air and pulmonary blood takes place efficiently. The apparatus carries out the steps of the method: (1) determining for a first breath during normal steady state breathing of the subject the end-tidal carbon dioxide or oxygen concentration Pet1 and the average rate of flow Va1, over the duration T1 of the breath, of expired carbon dioxide or oxygen, (2) determining for a second breath comprising a breath-hold period the end-tidal carbon dioxide or oxygen concentration Pet2 and the average rate of flow Va2, over the duration T2 of the breath, of expired carbon dioxide or oxygen, and (3) determining EVG as a quantity proportional to the ratio of the difference between said average flow rates Va1 and Va2 to the difference between said end-tidal concentrations Pet2 and Pet1.

Abstract: An interlock arrangement for evaporators in an anesthesia apparatus having at least two evaporators for setting a desired gas concentration prevents more than one evaporator from being activated at a time. The evaporators are connectable to a gas distributor. The interlock arrangement has for each evaporator, a mechanical element with the mechanical elements being arranged so that they cross each other in a crossing region. The mechanical elements are fashioned in the crossing region so that the mechanical element for one evaporator is displaced when this evaporator is activated and thereby locks the other mechanical elements in a position in which an activation of the further evaporators is prevented.

Abstract: A vaporizer for vaporizing a liquid anaesthetic has an inlet for a carrier gas, an outlet for the carrier gas and vaporized anaesthetic, a flow channel connecting the inlet to the outlet, a chamber for liquid anaesthetic, a first connection between the flow channel and the chamber, a second connection between the flow channel and the chamber downstream from the first connection and a throttle in the flow channel between the first connection and the second connection. The second connection has a conduit, one end of which is immersed in the liquid anaesthetic, and a valve connected to the other end of the conduit so as to increase safety, prevent leakage and erroneous dispensing and allow the use of liquid anaesthetics with a low boiling point. The valve is devised to open when there is a predetermined drop in pressure across the throttle, allowing liquid anaesthetic to be dispensed into the flow 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: An anaesthetic gas filter, devised for connection to an anaesthetic machine, for absorbing/adsorbing anaesthetic gas, allows the need for replacement to be determined without the leakage of any anaesthetic gas. for this purpose, the anaesthetic gas filter has an anaesthetic gas detector arranged in the filter. An early indication of the need to replace the filter is then provided.

Abstract: An anaesthetic machine for connection to a patient's airways has a fan with an inlet and an outlet, a first system of flow paths connected between the fan's outlet and inlet, and a second system of flow paths connected between the fan's outlet and inlet. A fast system with wide variability with respect to operating modes is achieved by arranging a shunt valve at the fan's outlet in order to regulate the amount of gas flowing into the first system of flow paths and the second system of flow paths respectively, and a control unit is provided to control the shunt valve.

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: A safety system prevents inadvertent mixing of different anaesthetic agents, during replenishment wherein a new anaesthetic is replenished from a container to an anaesthesia machine containing a flow channel for the delivery of liquid anaesthetic, with a first anaesthetic being present downstream from the flow channel. Inadvertent mixing of different anaesthetics is avoided because the safety system has a measurement unit for identifying the new anaesthetic before the new anaesthetic comes into contact with the first anaesthetic. The measurement unit is arranged upstream from the first anaesthetic.

Abstract: A high frequency oscillator (HFO) ventilator has an oscillator unit for alternately supplying a volume of gas (“oscillator volume”) to and removing the oscillator volume from a proximal end of a gas conduit at a predetermined high frequency. The gas conduit has a proximal end connectable to the oscillator unit and a distal end connectable with the patient's airways. Located between the proximal end and the distal end is an inlet for receiving a continuous flow of a bias gas from a supply, and an outlet. The ventilator further has a flow controller adapted to apportion, between the distal end of the conduit and the outlet, the volume of gas supplied by the oscillator unit to establish a predetermined inspiration tidal volume for delivery to the patient's airways independent of the oscillator volume.

Abstract: An interface unit for establishing an electrical coupling of a number of sensor wires from a combination of catheters with a number of electrical signal channels of a electrophysiological monitoring system has a number of electrical contacts for coupling individual wires with individual channels. Each contact is releasably engageable with an individual wire. A number of overlays which are removably locatable at the outer surface and are attached to the housing of the unit by binding rings. Each overlay carries on a face thereof a visible indication of a different one of a number of stored wire/contact configurations. The configurations are organized such that contacts for receiving wires from a same catheter are grouped together and the indication is formed as visibly differentiated regions, each de-marking a different grouping.