Abstract: A signal detector for detecting a biosignal with approximately known morpogy in a complex input signal (ECG), in particular for the detection of QRS complexes in an electrocardiogram. The detector has circuitry for detecting the maximum amplitude (PEAK) of the detected signal complex within a predetermined time window, with a threshold value discriminator, a detector parameter preselection circuit for determining an initial value for the detector parameter characterizing the detector sensitivity, which parameter determines the detector threshold value when responding to a detection signal in dependence on the maximum amplitude and a detector parameter timing circuit for adjusting a predetermined time dependence of the detector parameter and thus the detection threshold value.

Abstract: A therapy device having at least one sensor for detecting a variable that n be measured on the body of a patient in the application of a predetermined therapy, and for outputting a corresponding measured value, an evaluating and control device that is connected to the output of the sensor, and a therapy device that is connected to the output of the evaluating and control device and is configured for realizing different therapies as a function of the association of the value of the measured variable with a predetermined value range, with the evaluating and control device having a range-limit memory, a comparator unit for associating the measured value of the variable with one of the value ranges, a therapy memory having at least two separately-addressable memory regions for storing at least two different values of the therapy-control variable in association with the values of the measured variable within an overlap zone between two value ranges, a past-history memory and past-history evaluation means for trans

Abstract: A method of storing signals having a course over time in an implantable medical device, and/or transmitting the signals out of the device and out of the patient's body, with the course over time being detected in the device, particularly at predetermined time intervals with a constant sampling interval, and a sequence of signal samples being obtained therefrom, of which a partial quantity is stored and/or transmitted as the result of a selection made with a predetermined selection criterion, with the selection criterion being the first derivation of the course over time of the signals according to time, and with the selection being made such that the first derivation of the straight-line connection between an nth and the (n-1)th signal sample is determined and compared to the first derivation of the straight-line connection between the (n-1)th signal sample and the last-stored and/or last-transmitted signal sample, and the nth signal sample is then stored and/or transmitted as the new last signal sample exact

Abstract: A medical therapy device includes at least one sensor for detecting a varle that can be measured on the body of a patient. An evaluating and control device is connected to the output of the sensor. A therapy device is connected to the output of the evaluating and control device and provides different therapies or therapy variables as a function of the value of the therapy control variable. A processing unit has an input connected to the output of a time controlled fluctuation-value generator which is connected between the output of the sensor and the input of the evaluating and control device.

Abstract: An implantable defibrillation system with an intercardial or subcutaneous defibrillation electrode is provided wherein the defibrillation electrode includes portions with a porous surface coating having an active surface area substantially larger than a surface area resulting from the basic geometrical shape of the electrode.

Abstract: An arrangement is provided for controlling a stimulation frequency of a pacemaker. The arrangement includes an atrial bipolar electrode system and a ventricular bipolar electrode system. A first electrode pair comprises an electrode from each of the atrial and ventricular bipolar electrode systems, with the electrodes of the first electrode pair being disposed intracardially in the atrium and ventricle, respectively. A pacemaker control unit generates stimulation pulses for stimulating the heart. A constant current source impresses a constant current to a second electrode pair, comprising at least one electrode from one of the atrial and ventricular bipolar electrode systems being disposed intracardially in one of the atrium and ventricle, for developing an electrical potential between the electrodes of the first electrode pair during predetermined cardiac phases.

Abstract: A cardiac pacemaker system is provided which includes a stimulation electrode adapted for being anchored in the heart. An output capacitor is coupled to the stimulation electrode. A first circuit coupled to the output capacitor generates stimulation pulses. A second circuit coupled to the output capacitor generates an autoshort pulse following each stimulation pulse to reduce a residual charge of the output capacitor for eliminating an after potential following a stimulation pulse by the stimulation electrode. A third circuit coupled to the output capacitor acquires an evoked pulse of the heart from an electrical signal picked up by the stimulation electrode. The stimulation electrode includes a porous surface coating made of an inert material and has an active surface that is substantially larger than a surface of the basic geometric form of the stimulation electrode.

Abstract: A circuit for determining the impedance in a heart having a pacemaker electrode to which voltages are applied disposed in the ventricle chamber thereof. The circuit uses the pacemaker electrode. The circuit includes a current source operatively connected to the pacemaker electrode to apply current thereto, the current source having a current direction which can be switched. Switching circuitry is provided for switching the current direction of the current source. The voltage applied to the pacemaker electrode at different measuring times is measured with measuring circuitry. A value representative of the impedance in the heart is determined from a difference between the voltages applied to the pacemaker electrode at two of the different measuring times measured by the measuring circuitry. Currents having an identical magnitude but having opposite directions are applied to the pacemaker electrode by the current source which is switched by the switching circuitry at the two respective measuring times.

Abstract: A stimulation electrode having a porous surface coating whose active surface area is significantly greater than the surface area defined by the geometric shape of the electrode, wherein the surface coating comprises an inert material, i.e. a material having no or only a very slight oxidation tendency, wherein the material of the surface coating is formed from an inert element, an inert chemical compound and/or an inert alloy, and the active surface area, by virtue of its fractal-like geometry, is greater by a factor of at least one thousand than the surface area defined by the basic geometric shape of the electrode.

Abstract: A demand cardiac pacemaker implantable in a patient which includes a pulse generator which generates stimulating pulses at a controllable variable rate and has electrodes for applying stimulating pulses from the pulse generator to the heart of a patient. The length of the pre-ejection period (PEP) for the left ventricle in each heart cycle, which length is a function of the physiological demand of the patient, is detected and an output signal which is a function of the length of the pre-ejection period is produced. This output signal is used to control the pulse generator to produce stimulating pulses at a rate based on the output signal, and to apply the stimulating pulses to the electrodes in the absence of spontaneous heart action.

Abstract: A device for generating a therapeutic value for a patient as a function of t least one variable parameter picked up within the body and constituting a first input value, with a change in the first parameter being a function of a second parameter which also constitutes an input value. The device includes circuitry for varying the generation of the therapeutic value by varying the second parameter so that the difference of the values of the first parameter, at selected limits of a variation range of the first parameter, constitutes a maximum in an intended treatment range of the patient. A memory retains a value of the second parameter for which the variation range of the first parameter constitutes a maximum. Control circuitry changes the therapeutic value as a function of the first parameter while maintaining the previously stored second parameter.

Abstract: A neurostimulator for generating stimulation pulses for the central or peripheral nervous system, particularly against pain in the region of the spinal cord includes a control circuit for generating stimulation pulses with a pulse generator whose output is connected with stimulation electrodes. The stimulation pulses are generated at periodic intervals with an activity period corresponding essentially to an effective duration corresponding to a biological half-lifetime of a body's own active substances. The control circuit creates a respective rest period corresponding to a time required by the body's own active substances to regenerate themselves for a corresponding activity period.

Abstract: A controlled-rate, artificial cardiac pacemaker (14) comprises a module (12) for adapting the stimulation rate to the patient's actual physical load. In the case of limited or non-existent activity, the output signal of a sensor (10, 11) for the patient's activity status constitutes a control signal for a circuit (20) which reduces the energy supplied to the module for adapting the stimulation rate of the artificial cardiac pacemaker to the patient's actual physical load.

Abstract: A stimulation system for a skeletal muscle in a patient having a heart tred with cardiomyoplasty, for use as a supplement to a conventional cardiac pacemaker circuit, includes a stimulation unit for producing output signals to stimulate the skeletal muscle under control of the cardiac pacemaker circuit, and a plurality of implantable electrodes connected to the stimulation unit and the skeletal muscle, for selectively delivering output signals from the stimulation unit to the skeletal muscle. The stimulation unit output signal intensity is controlled by the cardiac pacemaker circuit to follow a value representative of the momentary physical stress and cardiovascular requirement, respectively. The value representative of the cardiovascular requirement includes an autonomous nervous system activity value which is substantially independent of further influential values.

Abstract: A cardiac pacemaker control system includes a stress detector system (1) for producing a controlled basic stimulation rate based on signals picked up within a patient's body related to physical stress and derived from a pre-ejection period of the patient. A detection device (10, 15) detects a spatial orientation of the patient, and produces an output switching signal (20) for changing the controlled basic stimulation rate depending upon the position of the patient which represents an additional measure of physical stress.

Abstract: A cardiac therapy system for use with a conventional cardiac pacemaker ciit is controlled by activity signals of the autonomous nervous system (ANS) in a patient's body which constitute a measure for the patient's cardiovascular output requirement.

Abstract: A rate controlled cardiac pacemaker stimulates the heart of a patient at a stimulation rate and includes a stress sensor for sensing actual physical stress of the patient. The device includes control logic for adapting the stimulation rate of the pacemaker to the actual physical stress of the patient and determining circuitry for determining the activity of the patient. The determining circuitry includes an activity sensor for sensing the activity state of the patient and a rate control circuit having an input connected with an output of the activity sensor. A timer generates a signal based on a 24-hour rhythm indicating a rest phase or an activity phase, and is synchronized by the activity sensor in a 24-hour rhythm with patient activity and rest phases that occur in continuous alternation.

Abstract: A plasma enhanced chemical vapor deposition (PECVD) process for producing an amorphous semiconductive surface coating consisting essentially of hydrogenated silicon carbide (a-SiC:H) having an improved blood compatibility, the process including positioning a substrate to be coated in a reactor chamber; heating the substrate to a substrate temperature ranging from 0.degree. C. to 350.degree. C.; providing a flow of a reactive gas mixture including from about 50 to about 100% of methane (CH.sub.4), from about 0 to about 50%, of silane (SiH.sub.4), and from about 0 to about 2% of phosphine (PH.sub.3), the flow having a flow rate based on a flow rate of silane (SiH.sub.4) which ranges from 10 to 50 sccm, the methane (CH.sub.4) and the phosphine (PH.sub.3) having respective flow rates which are based on the flow rate of the silane (SiH.sub.4); introducing the flow of the reactive gas mixture into the reactor chamber to provide a process pressure ranging from 0.

Abstract: A cardiac pacemaker includes an activity sensor for detecting physical activity of a patient and generating a momentary output signal and an activity clock cycle generator having an adjustable clock cycle rate adjustable to the activity of the patient, for generating stimulation impulses for cardiac muscles of the patient at a rate defined by an end of one of a basic rate interval and an escape interval, the basic rate interval being a normal interval between stimulating impulses, and the escape interval being an on-demand interval between stimulating impulses.

Abstract: Implantable cardiac pacemaker with a plurality of inputs for signal reception and switchable capacitors connected to these inputs, whereby analog signals obtained through signal receivers from external and/or internal sources are consecutively transmitted on a common signal transmission path inside and/or outside the cardiac pacemaker housing.