Abstract: A portable anaesthetic machine allows dispensing of a liquid anaesthetic to a patient, which is sometimes desirable and may be hard to achieve, especially with portable equipment. This portable anaesthetic machine has a gas flow generator for generating a flow of gas at an adjustable pressure and/or flow rate, an inspiratory line and an expiratory line. The gas flow generator, inspiratory line and expiratory line constitute the gas flow pathways for the respirator. A membrane is arranged in the gas flow pathways, made of a self-sealing material. The membrane can be punctured by a syringe needle for dispensing the liquid anaesthetic into the gas flow pathways an optional number of times.

Abstract: A conduit connectible in a fluid transfer system to provide for the through flow of a fluid moving between a transfer device and internal patient includes a transmission line incorporated therewith having a distal end for signal communication with a signal generator and a proximal end connected to a terminal on a mating surface of a female connector and arranged thereon to establish a signal transmission path with a terminal on a mating surface of a second conduit, such as a port of the fluid transfer device, as the mating surfaces engage to establish fluid communication between the conduit and the port.

Abstract: A ventilator for respiratory care, intended for connection to a patient, avoids needless alarms, caused by a patient's attempts to speak and needless suffering because of the patient's inability to trigger an alarm, by having a sound detector arranged to detect and identify sounds made by the patient, preferably intentionally. A control unit is operatively connected to the sound detector acts on at least one function in the ventilator on the basis of sounds identified by the sound detector.

Abstract: A high-frequency oscillator (HFO) ventilator has a gas conduit with an opening for gas connection with a patient's airways and a bias gas flow inlet and outlet disposed to define therebetween a bias gas flow-path within the conduit. An oscillator is operable to induce pressure oscillations in gas within the conduit to move a volume of gas (“tidal volume”) along a respiration flow-path, intersecting the bias gas flow-path, alternately in to and out of the opening at a predetermined high-frequency to provide, respectively, an inspiration phase and an expiration phase of a breathing cycle. The HFO ventilator further has an extraction device operable during the breathing cycle, and preferably in timed relation with the operation of the oscillator, to withdraw an additional amount of gas from the respiration flow-path.

Abstract: In a method for locating a measurement and/or treatment catheter in a vessel or organ of a patient relative a fixed catheter, also positioned within the patient in the vicinity of the measurement and/or treatment catheter signals are transmitted from one of the catheters and received at the other one. The position and direction of the measurement and/or treatment catheter relative to the fixed catheter is then determined from the received signals. An arrangement for locating a measurement and/or treatment catheter, intended to be positioned in a vessel or organ of a patient, also includes a fixed catheter, also intended to be positioned within the patient in the vicinity of the measurement and/or treatment catheters. One of the catheters has a signal transmitter and the other one has a signal receiver for receiving signals from the signal transmitter. A signal processor determines from the received signals the position of the measurement and/or treatment catheter relative to the fixed catheter.

Abstract: A bellows arrangement for a ventilator/anesthesia system has a rigid container in which a bellows is arranged. The first end of the bellows is fastened to one end of the container, and the other end is displaceable relative to the first end. The container is connected to a propellant source of the ventilator/anesthesia system, and the bellows is in gaseous communication with a respiratory circuit of the ventilator/anesthesia system at the first end. In order to insure that the bellows always moves smoothly in a simple and inexpensive fashion, the second end of the bellows is provided with a guidance fixture which is connected to the container in every position of the second end so that, in an expansion or compression of the bellows, the second end is always displaced along the center axis while remaining substantially of the bellows parallel to the first end.

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: In a method for assessing pulmonary stress, a flow of respiratory gas is supplied to the lungs of a subject, an ensuing pressure is measured in relation to time and the pressure-time relationship is analyzed. In this analysis, the profile of the pressure-time relationship is determined. In summary, the profile is straight when no stress is present, is convex when there is a risk for over-distension, and is concave when alveolar units are opened up. Implemented in a breathing apparatus the method can be used to assist an operator in diagnostic and therapeutic considerations in relation to a patient.

Abstract: A high-frequency oscillator ventilator has a first gas conduit with an opening for gas connection with a patient's airways and a bias gas flow inlet and a bias flow outlet disposed to define therebetween a flow path for a bias gas within the first conduit. An oscillator operable to alternately introduce a volume of additional gas from a source into, and to withdraw at least the same volume of gas from, the first gas conduit, thereby inducing pressure oscillations in gas within the first conduit to move gas along a path intersecting the flow path for a bias gas alternately into and out of the opening at a predetermined high-frequency dependent on the output of a control signal generator.

Abstract: In a method and apparatus for determining at least one parameter related to a patient's spontaneous attempts at inspiration and/or the patient's respiratory effort in attempts at spontaneous inspiration, a pressure gradient is determined in relation to a known apparatus pressure and time, the pressure gradient being generated by the patient at inspiration, a residual positive pressure in the patient's lungs is determined and an output signal is generated. The output signal can represent determined parameters as well as other related calculated results. The pressure gradient can be extrapolated against residual positive pressure, and both a delay for respiratory assistance and true inspiratory effort can be determined.

Abstract: In a method for seeking and setting a resonant frequency for a load impedance and a tuner for carrying out the method, a first frequency sweep is performed over a predetermined frequency interval in order to identify the resonant frequency within the predetermined frequency interval. To maintain the correct resonant frequency, regardless of signal drift and other interference, repeated sweeps are automatically performed within the predetermined frequency interval to identify the resonant frequency repeatedly. Alternating semi-sweeps can be performed to reduce the sweep duration.

Abstract: A gas pressure generator for a ventilator includes a variable volume container provided with an inlet connectable to a fresh gas supply and an outlet connectable to a respiration circuit of the ventilator and a driving fluid-actuated piston having a shaft with a piston head for transmitting the force to the variable volume container at one end and an opposite end, at which the force is generated, being moveable in a driving fluid chamber so to reduce the volume of the container to maintain a substantially constant output pressure of contained fresh gas. The driving fluid is maintained at a substantially constant pressure with the piston shaft and the chamber relatively dimensioned such that the percentage volume change within the chamber as the shaft moves therein is no greater than an allowable percentage variation in the output pressure of the fresh gas.

Abstract: A vaporizer for vaporizing liquid anesthetic has a chamber for liquid anesthetic, a gas flow passage, a throttle in the gas flow passage, a first connection between the chamber and the gas flow passage upstream from the throttle and a second connection between the chamber and the gas flow passage downstream from the throttle. The vaporizer is more accurate and usable with different liquid anesthetics by having an outlet valve arranged by an outlet in the vaporizer, this outlet valve being regulated by the pressure upstream from the throttle.

Abstract: A catheter arrangement has an active catheter, positionable in a vessel or organ of an animal, having at least one transducer disposed proximal the catheter tip; and a fixed catheter, also positionable within the animal in the vicinity of the active catheter, carrying a number of reference transducers. A signal processing unit is arranged to selectively operate the transducers to send and receive signals between the active and fixed catheters. The signal processing unit operates to calculate from the received signals at least two independent locations of the active catheter relative to the fixed catheter and to combine the independently calculated locations to provide a weighted average determination of the location in which the relative contributions of the calculated locations to the determined location decrease as their associated error values increase.

Abstract: A dosing device for regulating the concentration of a liquid vapor, produced by vaporizing liquid from a liquid source, in a carrier gas has on-off valve which is automatically operable by a valve controller and which is connectable to one or both of the liquid and the carrier gas. A flow meter is provided in the flow path of the liquid and generates an output signal proportional to the flow of the liquid supplied for vaporization. This signal is supplied to the controller which cooperates with the valve to automatically regulate the supply of one or both of the liquid or carrier gas dependent on the output signal.

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: An apparatus for locating an electrically active site within an organ or other internal body structure has a number of electrical activity sensors positionable proximate a wall of the organ or internal body structure and relatively locatable. Each sensor produces an output indicative of the arrival of an electrical signal from the active site and a signal processing unit to utilize the series of outputs to determine, by triangulation, the location of the active site.

Abstract: In a method for controlling an expiratory valve in a ventilator during expiration, the expiratory valve is opened substantially fully for a first interval. Fully opening the expiratory valve has the advantage of minimizing the expiratory resistance a patient needs to overcome. Keeping the expiratory valve open as long as possible during expiration, without losing control of positive end expiratory pressure (PEEP), is therefore advantageous. An optimal system is achieved. In a method wherein pressure in the expiratory section of the ventilator is measured during a second interval, the expiratory valve is regulated so a predetermined end pressure is obtained in the expiratory section, and at least one parameter, directly or indirectly related to control of the expiratory valve, is determined, and a determination is made from that parameter as to whether the next first interval for the next expiration should be longer than, shorter than or as long as the first interval.

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 body fluid analysis system having a sensor and a method for flushing and single-point calibration of the sensor, a container holding at least one flushing liquid has a first tube connected thereto at a first point and at a second point to form a closed system. The sensor is connected to the first tube, and to a second tube for connection to a patient. A pump is connected to the first tube between the container and the sensor.