Abstract: In a method and a ventilator device for measuring the functional residual capacity, FRC, of lungs, a trace gas is mixed with a breathing gas in a gas mixer and the mixture os fed into the lungs via an inspiratory tube. When a predetermined concentration of trace gas is achieved in the lungs, the supply of trace gas is stopped, and a washout phase starts. During the washout phase, the concentration of trace gas in expired gas and the flow of expired gas are measured. The measurement values are sent to an analyzer which calculates the volume of trace gas in the lungs. Functional residual capacity can then be determined from the calculated volume of trace gas. The trace gas is preferably SF.sub.6.

Abstract: A safety system is provided for anesthetic systems with at least two anesthetic vaporizers, the safety system preventing the simultaneous supply of anesthetic to a breathing circuit by more than one anesthetic vaporizer. The safety system which prevents this includes a setting means for each vaporizer which emits an activation signal when moved from an OFF position to an active position. The activation signal is received by a control unit which then sends a control signal to blocking valves, respectively arranged by the anesthetic vaporizers, and prevents the passage of breathing gas to more than one anesthetic vaporizer for vaporization of an anesthetic.

Abstract: A device for eliminating ringing in filtered ECG signals includes an analog-to-digital for converting the ECG input signals into a series of digital values, and a filter unit connected to the output of the analog-to digital converter. The filter unit includes a recursive IIR-filter and a subsequent allpass filter with a phase shift which is equal to twice the phase shift of the IIR filter. The allpass filtering is performed time-reversed with respect to the IIR filtering. In a method for producing an allpass filter, for use in the above device, having a phase shift which is equal to twice the phase shift of an IIR filter, the IIR filter having zero points situated on the unity circle in the Z-plane, the zero points of the IIR filter are replaced by new zero points obtained by reflecting the poles of the filter in the unity circle in the Z-plane.

Abstract: A method for gas analysis includes the steps of extracting a gas sample from a gas to be analyzed with respect to one or more of its gas components, measuring the flow of the extracted gas sample, and adding a replacement gas to the gas in the same amount as the extracted sample in order to minimize the impact on the main gas flow of the extraction of the gas sample. The replacement gas can consist of the same gas components constituting the gas sample. A gas analyzer for performing the method is also disclosed.

Abstract: A device which supplies breathing gas mixed with an additive gas to a patient for pulmonary diagnosis or pulmonary treatment includes a gas mixing unit through which a relatively large flow of breathing gas is achieved from a first gas source through a first pressure regulator and a second pressure regulator. The breathing gas passes through a connecting tube from which the patient can breathe spontaneously through an inspiration tube, thereby inhaling air from the connecting tube. Expired gas passes via an expiration tube to the connecting tube. Additive gas is supplied from a separate gas source via a second pressure regulator and a second flow regulator. The additive gas is supplied in a flow which is considerably smaller than the flow of breathing gas, permitting a very small but accurate concentration of the additive gas to be achieved in the breathing gas. The large flow prevents a reactive additive gas from reacting before being supplied to the patient.

Abstract: An implantable cardiac stimulator has an atrial electrode for placement in the atrium of a heart and a ventricular electrode for placement in the ventricle of the heart. In order to sense stimulated events in the heart, a detector is connected to both of the electrodes to measure electrical heart signals between them.

Abstract: A pressure and heart movement sensor for a heart stimulator, includes an electrode system for implantation with an electrode cable containing at least two electrical conductors leading to electrode poles. A measurement device is arranged to measure an electrical quantity between the electrical conductors, which quantity varying according to the pressure applied to the electrode cable. Alternately, the electrode cable contains at least one electrical conductor, and the measurement device is arranged to measure the impedance between the conductor and ambient medium and to deliver an output signal, which varies according to the impedance measured, when the electrode cable is subjected to pressure.

Abstract: A capillary unit for an ink jet printer, having a nozzle for spraying a jet of ink onto a record carrier. The jet of ink breaks up into a series of droplets at a droplet formation point in front of the nozzle. A charging electrode, with which the ink droplets are selectively charged for subsequent electrical deflection, is arranged in the area of the droplet deflection point. The charging electrode is devised in the form of a plate, arranged perpendicular to the path of the jet, with a through hole for passage of the droplets. The charging electrode is further devised with at least one groove running from the hole to the outer edge of the electrode.

Abstract: Known implanted medication infusion systems have a medication container and a pump for pumping medication from the medication container into the patient via a catheter connected to the output of the pump. A flushing port is arranged downstream of the pump and upstream of the catheter. In a method for cleaning the catheter, a cleaning fluid is flushed through the flushing port and into the catheter. The orifice of the catheter is, during cleaning, placed in communication with the exterior of patient, and is isolated from the interior of the patient in order to convey the cleaning fluid out of the patient.

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.

Abstract: A device for affixing an electrode cable to an apparatus is disclosed, suitable for affixing an electrode cable for use in vivo to an implantable medical apparatus for emitting electrical pulses, such as a pacemaker or a defibrillator, wherein the electrode cable has a pin-like proximal end. The apparatus is provided with a connector part at which the affixing device is located to mate with the proximal end of the electrode cable. The affixing device includes a spring element which is disposed substantially perpendicularly to the longitudinal axis of the proximal end of the electrode cable when the proximal end is contained in the connector part. The spring element carries clamping elements, and the spring element is movable between first and second positions.

Abstract: In a method and apparatus for determining the volume of a bellows reservoir for medication in an infusion system which is implantable in a patient, the pressure in the reservoir is measured and the corresponding volume is determined from a predetermined relationship between pressure and volume. A pressure gauge is disposed for measuring the pressure in the bellows reservoir, and a signal corresponding to the measured pressure is supplied to a memory unit wherein a corresponding volume is determined from the measured pressure value by means of the predetermined relationship between pressure and volume being stored in the memory unit.

Abstract: The invention is directed to an external pump stroke indicator for use with in an implanted medication infusion system of the type having a pump for conveying medication into the patient, an opening covered by a septum is arranged at the output of the pump. The indicator includes a cylinder composed of a transparent material and connectable via its lower end to the opening in an essentially upright attitude, the cylinder being filled with a liquid. A movable sinker member is provided in the cylinder, the movable sinker member normally resting as a result of its weight against a seat provided in the cylinder that limits the motion of the sinker member in the direction of the lower end of the cylinder. The sinker member is composed of a material that has a higher density than that of the liquid, so that the sinker member normally rests against the seat and only moves when pressure elevations that are generated by the pump strokes of the infusion system arise in the liquid.

Abstract: In a method for supplying fresh gas in manual ventilation of a patient and in a ventilator system for practicing the method, the supply of fresh gas to a breathing bag is regulated. During inspiration, the breathing bag is squeezed, imposing an inspiration on the patient. A detector at the breathing bag senses when the patient exhales, and an identical flow of gas is fed to the system via an inspiratory valve, the flow of fresh gas is directed into the breathing bag and expired gas is prevented from entering the breathing bag. An expiratory valve simultaneously opens to conduct expired gas out of the system.

Abstract: An electrode system for pacemakers has at least one ventricular electrode, intended for placement in contact with heart tissue in the ventricle in order to sense electrical activity and stimulate and connected to a conductor for transmitting signals to and from the electrode. The part of the conductor nearest to the ventricular electrode is in the form of an insulated needle, helix or screw for puncturing or screwing into the part of the atrial wall facing the septum during implantation and having a sufficient length to permit the conductor to extend into the septum or superior part of the outer ventricular wall.

Abstract: A temporarily implantable electrode device, intended for sensing electrical signals from living tissue, has an insulating sheath of resorbable material, and at least one non-toxic, liquid conductor contained inside the insulating sheath in order to form an electrical conductor which, via an electrode adapted for interaction with living tissue can sense and carry electrical signals from living tissue to a medical apparatus connected to the electrode device. The resorbable material ultimately dissolves completely into the body of the subject in whom the electrode device was temporarily implanted, and the non-toxic, liquid conductor simultaneously mixes with other fluids, making explantation of the electrode device unnecessary.

Abstract: In a method and apparatus for processing ECG signals for the purpose of detecting low-amplitude signal structures hidden in noise in the ECG signal, the ECG signals, number of cardiac cycles are analog-to-digital converted, and QRS complexes in the converted signals are detected. The signals from at least two cardiac cycles are cross-correlated, and the correlation between these signals in time intervals which comprise at least the time intervals of the two samples is determined. An output quantity representing the degree of correlation is thus obtained, the magnitude of this quantity designating the amplitude of the signal structure in question. This magnitude can then be analyzed to determine if, and where in the signal, the signal structure arises.

Abstract: An x-ray examination apparatus has a stand composed of at least one upright column, a holder for a curved carrier rotatable around a horizontal axis and connected to the column, an x-ray tube and a receptor being secured to the holder, a fastening means for the stand, and an arm that connects the stand to the fastening means. One end of the arm is rotatable around an axis at the fastening means. The apparatus also includes an examination table that is displaceable at least along a center line.

Abstract: A method and apparatus are disclosed for tracing leaks in vivo which occur in an electrode device, such as a pacemaker or a defibrillator, the electrode device including an electrode cable containing an elongate, flexible conductor having an exterior covered with a layer of insulation and having an interior channel. A leakage tracing device which is simple in structure, and therefore inexpensive to make, and with which one or more leaks in an electrode cable implanted in a patient is/are readily detectable, has a tubular, flexible body within an external diameter smaller than inner diameter of the interior channel of the electrode cable. The tubular body can be inserted into the electrode cable's interior channel all the way to the channel's distal end, and the proximal end of the tubular body is connected to a container for a fluid.

Abstract: An apparatus for measuring electrical activity in the heart, such as an ECG apparatus, has an input amplifier with multiple inputs to which the respective poles of electrodes introduced into a patient are intended to be connected. The input amplifier includes a sensing stage for sensing the impedance across the amplifier inputs after connection of the electrodes, in order to identify the poles which are in contact with the patient's heart. A display is connected to the input amplifier to graphically indicate which electrode poles are connected, and which are in contact with the heart.