Pacesetter Ab

Siemens Elema Ab

Siemens Aktiengesellschaft

Siemens Aktiengesell Schaft

Kurt Hoegnelid

Kjell Noren

Kenth-Ake-Sune Nilsson

Pia Hagel

Sven-Erik Hedberg

Hans G Strandberg

Martin Obel

Jan Ljungstroem

Liliane Wecke

Nils Holmstroem

Heinz Neubauer

Ake Sivard

Jens Wolf

Roland Heinze

Hans T Thornander

Agneta Franksson

Goran-Sven Budgifvars

Pierre Westin

Karin Ljungstroem

Bjoern Dalen

Alf Oehman

An implantable heart defibrillator includes a pulse generator controlled by a control unit for emitting defibrillation pulses. The pulse generator is controllable to emit a number of low-energy defibrillation pulses, having a lower pulse amplitude and a shorter pulse duration than a conventional defibrillation pulse, with the total energy in the number of low-energy defibrillation pulses being less than the energy in a conventional defibrillation pulse. Each pulse in the number of low-energy defibrillation pulses, however, contains enough energy to depolarize heart cells oriented favorably in relation to the direction of the electrical field of the low-energy defibrillation pulse.

Implantable heart defibrillator

A device for detecting hemodynamic conditions in a heart, in particular conditions corresponding to dangerous arrhythmias contains a sensing unit for a physiological variable, such as blood pressure, the unit emitting a signal on the basis of the variable having an average value, a signal conditioning unit connected to the sensing unit, a calculation unit connected to the signal conditioning unit and a comparator after the calculation unit. The calculation unit is devised to calculate a variability measure relative to the signal's average value, the variability measure being correlated to average blood pressure, and the variability measure is compared in the comparator to an adjustable threshold value corresponding to a specific hemodynamic condition, whereupon the comparator emits an indication signal when the variability measure falls below the threshold value.

Medical device for detecting hemodynamic conditions of a heart

A heart stimulator having a pulse generator and an electrode system, which contain at least one bipolar electrode with one pole arranged in the atrium and another pole in the ventricle, or at least two unipolar electrodes respectively arranged in the atrium and ventricle, for detecting atrial and ventricular activity includes an atrial measurement unit which is connected for measuring a signal between the two poles of the bipolar electrode, or between the two unipolar electrodes, and a ventricular measurement unit arranged to measure the signals between the ventricular pole (or electrode) and the housing of the stimulator.

Heart Stimulator

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.

Implantable cardiac stimulator

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.

Pressure and heart movement sensor for heart stimulators

A heart stimulator emits stimulation pulses to a heart, and has a regulator unit for regulating a variable function in the heart stimulator, a measurement device for measuring the return flow of blood to the heart, and a control device for controlling the regulation of the function by the regulator unit on the basis of changes in the return flow of blood. The regulator unit may be a pulse generator which generates and emits the stimulation pulses at a variable interval, the heart stimulator then becoming rate-adaptive and optimizing cardiac output. In this manner, heart rate is regulated on the basis of a variable directly related to the body's oxygenation needs.

Activity responsive heart stimulator dependent on return blood flow to

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.

Electrode system for pacemakers

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.

Resorbable temporary medical electrode device

An apparatus for producing heart defibrillation sequences formed of stimulation pulses and defibrillation shocks contains a unit for delivering pulses through an intracardiac or epicardiac electrode, normally for cardiac pacing, and defibrillator circuitry for delivering defibrillation shocks through defibrillation electrodes. The unit for delivering pacing pulses has an output stage which is capable of generating a stimulation pulse, delivered to the heart via the pacing electrode, having a higher energy content than a pacing pulse, but considerably less energy than a conventional defibrillation shock. A control unit is connected to the unit for delivering stimulation pulses and to the defibrillator circuitry for forming a defibrillation sequence consisting of stimulation pulses and defibrillation shocks. The control unit determines the timing for delivering the stimulation pulses and the defibrillation shocks.

Apparatus for producing heart defibrillation sequences from stimulation

A detector for sensing events in living tissue, such as electrical events in a heart, contains a microprocessor functioning as comparator which compares an input signal corresponding to electrical signals from the living tissue with a defined signal detection level, and an event is deemed to have occurred if the input signal exceeds the defined detection level. More reliable detection of events in the presence of noise is achieved by also providing an integrator which generates the input signal to the comparator by integrating electrical signals obtained from the tissue, the comparator then comparing the integrated signal with a detection level selected for use with the integrated signal.

Detector for sensing events in living tissue

A medical electrode device of the type suitable for delivering therapeutic electrical energy in vivo to tissue from an implanted pulse generator, includes a sleeve containing a conductor which is a non-metallic, non-gaseous fluid conductor. The non-gaseous, non-metallic fluid conductor may be a conductive gel or an electrolytic liquid.

Medical electrode device having a non-gaseous fluid conductor

An implantable heart defibrillator and a method for defibrillating a heart, employ a shock pulse generator for delivering a defibrillation shock to a heart, the delivered energy being mechanical. The shock pulse generator includes an electromechanical energy converter which generates, e.g., pressure, by means of a piezoelement, in a pressure chamber. Pressure is transmitted by a fluid in an electrode devised like a hydraulic line to a balloon-like electrode head in contact with heart tissue. The generated pressure causes the electrode head to expand and deliver a mechanical shock to the heart corresponding to the pressure.

Mechanical defibrillator and method for defibrillating a heart

For detecting tachyarrhythmia of the heart, the partial pressure of gases physically dissolved in the blood is measured, preferably the partial oxygen pressure pO.sub.2, and a fast variation and/or a variation of the measured partial pressure pO.sub.2 that exceeds a prescribed degree is utilized as a criterion for the detection of a tachyarrhythmia. An apparatus for treating tachyarrhythmia of the heart operating according to the above method includes a sensor for identifying the partial pressure of gases dissolved in the blood, an evaluation unit supplied with the sensor output for recognizing rapid changes of the partial pressure or changes of the partial pressure that exceed a prescribed degree, the output of the evaluation unit being connected to circuitry for triggering the tachyarrhythmia treatment.

Method for detecting tachyarrhythmia of a heart by measuring patient

A device for analyzing the function of a heart, containing a measurement unit for generating a first measurement signal related to a first electrical or mechanical heart variable and an evaluation unit for evaluating the measurement signal, further contains a circuitry for generating a parameter signal related to a heart variable, the evaluation unit analyzing the related values for the measurement signal and the parameter signal. The device can be used for detecting a number of functional aberrations, such as bradycardia, tachyarrhythmia, retrograde conduction, ischemia and ectopia, and for controlling pacemakers and defibrillators.

Device for analyzing the function of a heart

In a method for continuous, electrical monitoring of the electrodes of an electrical heart stimulator, having at least one stimulation electrode and an indifferent electrode, the inter-electrode voltage is kept constant by regulation of a very low compensating current, and the magnitude of this current is measured and monitored. A device for such electrode monitoring includes control electronics and an output stage for delivery to the stimulation electrode of stimulation pulses. The output stage is devised to supply the electrodes with a weak, continuous current, or a repeated, pulsed current, producing a net direct current, in addition to stimulation pulses. A monitoring unit senses the inter-electrode voltage and, on the basis thereof, deliver an output signal to the control electronics for the purpose of controlling the weak current so the inter-electrode voltage is kept constant at a given value. This output signal is monitored, with significant deviations thereof, or an inability to maintain the inter-electrode voltage constant indicating the presence of a fault in the electrode system.

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Vaesterhaninge, Sweden

Kurt Hoegnelid