Abstract: 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.

Abstract: A compact, power-sparing detector for detecting heart polarizations is described. The detector has a first operational amplifier which uses sensed heart signals from a heart as an input signal. By means of feedback coupling via a second operational amplifier, a resistor and a capacitor, the system strives to achieve a minimum voltage gradient across the input terminals of the first operational amplifier. When an electrical signal with a signal slope corresponding to a heart depolarization arrives at the input terminal of the first operational amplifier, the second operational amplifier is no longer able to damp the input signal, and a peak output signal is sent from the first operational amplifier to each of a first comparator and a second comparator, respectively.

Abstract: An implantable medical system, having an implanted therapy-generating apparatus which administers a medical therapy in vivo to a treatment site remote from the therapy-generating apparatus, includes at least one optical conductor connected between the therapy-generating apparatus and the tissue at the treatment site, or an additional implantable medical device. Energy and/or information can be transmitted by optical signals using the optical conductor, in a safe and noise-free manner. Each location at which the optical signals are to be transmitted or received is provided with an optoelectrical converter, or an electro-optical converter, as appropriate.

Abstract: A heart defibrillator includes a defibrillation circuit for delivering defibrillation pulses. The defibrillation circuit also emits a pre-pulse before the defibrillation pulse. The pre-pulse is not as intense as the defibrillation pulse, but is still intense enough to induce mechanical contraction of muscles in parts of the thorax and possibly the heart.

Abstract: A system for administering medical therapy includes an implantable medical apparatus containing an audio transmitter and an audio receiver for respectively transmitting and receiving extracorporeally audible audio signals. The system also includes an extracorporeal programming and control apparatus, which also includes an audio transmitter and an audio receiver. The medical apparatus can thus communicate directly, in both directions, with the extracorporeal programming and control apparatus by means of audio signals. Such communication can take place, for example, via a telephone line, so that the patient in whom the medical apparatus is implanted need not be physically present at the location of the extracorporeal programming and control apparatus in order to establish communication.

Abstract: An implantable defibrillator has a charging circuit which charges a capacitance, electrodes for delivering energy from the capacitance to a heart, and a switching stage for discharging the capacitance through the electrodes and across heart tissue to defibrillate the heart, as needed. A non-inductive current limiter is connected in vivo in the discharge path for limiting the current supplied to the heart tissue to predetermined maximum value.

Abstract: 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.

Abstract: An implantable heart defibrillator is equipped with at least one intracardiac defibrillation electrode. A post-therapy apparatus is arranged to emit, after a defibrillation pulse, at least one stimulation pulse through the defibrillation electrode, the stimulation pulse having energy far higher than the energy in a normal heart stimulation pulse for cardiac pacing, but less energy than a normal defibrillation pulse.

Abstract: An implantable cardioverter/defibrillator has an electrode system including two electrodes, at least one of the two electrodes being adapted for placement in a peripheral vein of the heart, the peripheral veins constituting the venous side of the coronary vessels running between the base of the heart and the apex of the heart.

Abstract: 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.

Abstract: 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.