Abstract: A defibrillator has a pulse-generating device with at least three outputs to which electrodes are connectable for delivering defibrillation pulses. A switching network is provided to reverse the polarity and/or to switch the voltages applied by the pulse-generating device, selectively and at predetermined times, among the electrodes.

Abstract: A device for heart therapy has a tacharrythmia detector unit, a control unit and a current generator. The current generator controlled by the control unit emits via an electrode system a first, pulsed current to a physiological representative of the parasympathetic nervous system in order to activate same in response to detection of an impending or established arrhythmia. The current generator is further caused by the control unit, in the event of tachyarrythmia detection to emit, via the electrode system, a second current to a physiological representative of the sympathetic nervous system in order to block same.

Abstract: An electrode apparatus, such as an intravascular or intracardiac pacemaker or defibrillation electrode with an electrode cable has a jacket of insulation enclosing a first elongated, flexible conductor, connected to a first electrode arranged on the electrode cable, and also enclosing at least a second conductor, connected to a conductive surface forming a second electrode arranged on the electrode cable at a distance from the first electrode.

Abstract: 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.

Abstract: A device for shaping an electrode cable, such as a medical electrode cable for use with a pacemaker, includes a substantially tubular element or sleeve, having a length which is relatively short in comparison to the length of the electrode cable. The internal diameter of the tubular element is only slightly larger than the exterior diameter of electrode cable, so that the tubular element can be slid on and off the electrode cable. When the tubular element is on the electrode cable, it surrounds a portion of the electrode cable. The tubular element is curved in a desired manner, and is sufficiently stiff so that the portion of the electrode cable surrounded by the tubular element conforms to the shape of the tubular element. The device is extremely simple and inexpensive and simplifies adaptation of the electrode for placement in a patient's heart.

Abstract: An electrode device, for intracardiac stimulation and/or defibrillation of heart tissue and/or sensing heart signals in a patient, has a soft, flexible electrode cable with an outer coating of insulation containing at least one elongate conductor connected to an electrode arranged on the electrode cable. In order to attain an electrode device of this kind which is structurally very simple and in which all the electrodes on the electrode cable can be applied to the heart wall in a very simple manner so the entire electrode surface faces the wall and firmly presses against it, the electrode cable is at least partially ribbon-shaped.

Abstract: An apparatus and method of electrochemically determining an oxygen concentration with an oxygen sensor that includes a working electrode. The working electrode has a potential profile that includes a first potential step (a first measuring potential), a second potential step (a second measuring potential) and a third potential step. A measuring period is provided at the first and second measuring potentials. The currents flowing at the first and second measuring potentials are calculated and integrated over time. One of the two measuring potentials may be varied, depending on the difference between the two integrals of the currents flowing at the first and second measuring potentials, until the two integrals equal 0. An oxygen concentration is then determined from the value of a potential which thereby results.

Abstract: A device for identifying abnormal conditions in a heart retrograde conduction and tachyarrhythmias in particular, includes a differentiating circuit electrically connected to a heart to be monitored in order to differentiate ECG signals from the heart. The differentiated signal is plotted against the ECG signal. The radius (distance from a point on the resulting curve from the origin of the plot axes) in the resulting curve is calculated in a calculator unit. The radius obtained is then compared with a threshold value in a comparator and a sequence for the progression of the radius in relation to the threshold value is obtained and compared with previously obtained sequences stored in a sequence analyzer.

Abstract: In an implantable defibrillator electrode having a large surfaced electrode in the form of a netting, a spiral, or a fabric of electronically conductive material or having an intracardial electrode in the form of a coil of electronically conductive material, the electrode is completely embedded in a biocompatible, hydrophilic, electrolytically conductive polymer or is covered by such a polymer.

Abstract: A combined telemetry and magnetic field detector unit for use in a medical implant includes control logic, a magnetic field indicator, a telemetry circuit containing a number of switches, and a coil unit. The control logic is arranged to operate the switches such that switching between the telemetry function and the magnetic field detection function of the combined unit is achieved so the coil unit is utilized for transmission of telemetry signals to and from a programmer as well as for magnetic field detection. For magnetic field detection, the coil unit, which consists of multiple parts, is connected by the control logic such that the parts respectively form a primary side and a secondary side of a pulse transformer, with the magnetic field indicator connected by the control logic to the pulse transformer's secondary side.

Abstract: A magnet position detector, particularly for implantable medical devices, has a resiliently supported coil, a current source delivering a current to the coil and a detecting device for detecting the movement of the coil in a magnetic field when fed with an electric current from the current source. The coil has a core with a non-linear B-H curve and the current source is a pulse source delivering current pulses with at least one positive and one negative side. The detecting device detects the movements of the coil in opposite directions respectively excited by differentiated signals respectively corresponding to the leading and trailing edges and permits the magnitudes of the respective, oppositely directed movements to be compared to each other, thereby indicating the position of a source of the magnetic field, relative to the coil, to be determined.

Abstract: An auxiliary body, for guiding a stylet into the stylet channel of an electrode cable in a medical electrode device whose proximal end is provided with a connector pin, has a first end provided with a cylindrical channel so the auxiliary body can be pushed onto the connector pin, a second end of the auxiliary body being provided with a cavity whose orifice is larger than the channel's opening. The cavity is connected to the channel and continuously narrows in such a way that the diameter of the channel end of the cavity is larger than the external diameter of the stylet and equal to or less than the diameter of the stylet channel.

Abstract: An arrangement, in particular a heart pacemaker, has a measuring device for recording a heart activity measurement parameter. In order to record the measurement parameter in such a way that it is rid of disturbing signals, and can thus be used to evaluate the physiological functions of the heart pacemaker, the arrangement contains switching means which evaluate the signal curve of a measurement parameter during a heart cycle (n+1) as a function of the frequency (f) or duration (t.sub.S) of the previous heart cycle (n).

Abstract: 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.

Abstract: In an electrode system for implantation in a heart, both the atrium and ventricle electrically interact with a medical apparatus. The electrode system has a single electrode lead having an atrial electrode at a distal end for implantation in the atrium before the electrode lead is advanced deeper into the heart so that a ventricular electrode in-line with and preceding the atrial electrode along the lead, is connectable in the ventricle of the heart. The electrode lead has a first curvature near the ventricular electrode and a second curvature near the atrial electrode in order to facilitate implantation of the electrode system and reduce mechanical loads on the heart after implantation. The electrode system can also be equipped with defibrillation electrodes and/or physiological sensors, thereby becoming multi-functional.

Abstract: An implantable electrode system includes a connector for connecting a proximal end of the electrode to an implantable medical apparatus, such as for stimulating living tissue, and a distal end at which a tip electrode is located. The proximal end and the distal end are connected by a conductor which electrically connects the medical apparatus to the electrode tip, and which is surrounded by a flexible insulating sleeve. In order to provide an indifferent electrode having a large surface area relative to the size of the tip electrode, the insulating sleeve is provided with a section formed by an electrically conductive, flexible material, which serves as the indifferent electrode. The flexibility of the electrode system is retained, while providing an indifferent electrode of optional size.

Abstract: An apparatus for determining a physical condition in a living subject by determining peripheral resistance to flow is wherein peripheral resistance to flow is determined by measuring changes in the pressure drop characteristic in an artery during diastole. The pressure drop characteristic can be determined by measuring absolute pressure, relative pressure or dimensional changes in the artery during diastole. The apparatus can advantageously be used in a rate-responsive heart stimulator.

Abstract: A device for stimulating heart tissue contains a stimulation unit connected via a switching device to an electrode system. The number of connecting lines between the stimulation unit and the switching device is minimized by emitting control signals and stimulation pulses from a common pulse signal output socket of the stimulation unit. The switching device contains a signal discriminator which separates the control signals from the stimulation pulses, the control signals then controlling the switching device such that the stimulation pulses are delivered to a specific part of the electrode system.

Abstract: 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.

Abstract: The invention relates to implantable devices and materials, in which at least one part of the surface is provided with a tissue-plasminogen activator (t-PA). In this way, inflammatory reactions of the body and the formation of fibrous capsules, which ordinarily occur after implantation, are avoided or reduced.