Abstract: A cardiac pacemaker for implanting in a patient includes a device for applying stimulating pulses to the heart of the patient at a rate determined by a pacing parameter; a device for detecting a first physiological parameter which is correlated with physical exertion of the patient and producing a first output signal representative of the first physiological parameter; a circuitry device receiving the first output signal for varying the pacing parameter as a function of the first output signal received as an input variable; and the circuitry device being a closed-loop control device which receives first output signal from the device for detecting the first physiological parameter, for determining one of (a) the product of the heart rate and the stroke volume and (b) the product of the heart rate and a single variable representative of the stroke volume as the cardiac output, to correspond to changes in the first output signal which represents a standard for the current physical exertion of the patient, for va

Abstract: A cardiac valve prosthesis includes a rotatably mounted, disc-shaped valve flap which is provided with two outwardly oriented, convex attachments disposed opposite one another at the points of intersection of a secant with the edge of the disc. The valve also includes an annular body having on its interior wall first recesses for receiving the convex attachments to thus form a bearing socket for the valve flap. At its interior wall, the annular body is provided with second recesses which communicate with the first recesses to form a passage for the convex attachments during insertion thereof into the first recesses.

Abstract: A cardiac pacemaker for implanting in a patient includes a device for applying stimulating pulses to the heart of the patient at a rate determined by a pacing parameter; a plurality of devices for detecting a corresponding plurality of physiological parameters which are respectively associated with physical exertion of the patient and producing a corresponding plurality of output signals representative of the corresponding physiological parameters; a circuitry device receiving the first output signals for varying the pacing parameter as a function of the first output signal, an external programming device in communication with the circuitry device; a linking element in communication with the external programming devices which selectably links the circuitry device with a selectable one of the plurality of device for detecting; and the external programming device causing the linking element to select a given one of the plurality of detecting device for linking with the circuitry device.

Abstract: A cardiac pacemaker implantable in a patient, including: a unit for apply stimulating pulses to the heart of the patient; a device for detecting at least one physiological parameter which is a function of left-ventricular systolic time intervals of the heart; a circuit connected to the detecting device for deriving a reference value which is a function of the physiological parameter; and a signal circuit connected between the circuit and the pulse applying unit for producing stimulating pulses at a rate based on the reference value in the absence of spontaneous heart action.

Abstract: Pacer control information adapting the pacers to an individual relating a ysiological parameter obtained from a first sensor to a corresponding parameter obtained from a second sensor is stored in a memory for later address in response to a signal from the first sensor to provide the corresponding pacer control information to the pacer generator.

Abstract: A cardiac pacer features plural addressable digital memory elements each containing different pulse parameters for the pacing stimulation, address-selecting digital logic circuitry for choosing the characteristics of the pulses to be generated in response to signals derived from plural physiological sensors detecting different exercise-related body functions to improve control of the heart during various levels of exertion.

Abstract: A cardiac pacer features plural adressable digital memory elements each containing different pulse parameters for the pacing stimulation, address-selecting digital logic circuitry for choosing the characteristics of the pulses to be generated in response to signals derived from plural physiological sensors detecting different exercise - related body function to improve control of the heart during various levels exertion.

Abstract: A cardiac pacer features plural adressable digital memory elements each containing different pulse parameters for the pacing stimulation, address - selecting digital logic circuitry for choosing the characteristics of the pulses to be generated in response to signals derived from plural physiological sensors detecting different exercise - related body function to improve control of the heart during various levels exertion.

Abstract: A cardiac pacer features plural addressable digital memory elements each containing different pulse parameters for the pacing stimulation, address-selecting digital logic circuitry for choosing the characteristics of the pulses to be generated in response to signals derived from plural physiological sensors detecting different exercise-related body functions to improve control of the heart during various levels of exertion.

Abstract: A cardiac pacemaker having circuitry for varying the pacing rate, in accordance with a signal recorded in the patient's body and correlated with the stroke volume, in which for automatic adaptation of the functional dependency of the pacing rate on the value correlated with the stroke volume at the maximum allowable or expected physical exertion on the part of the patient, the pacing rate is varied in a range adapted to this exertion; as a reference point for the functional dependency, the particular rate is associated with the particular stroke volume at which the product of the stroke volume and the pacing rate is a maximum.

Abstract: A cardiac pacemaker constructed for terminating tachyarrhythmias and including: an atrial electrode implantable in a patient's heart for supplying atrial stimulation pulses thereto and at which a pulse appears in response to each atrial contraction; a ventricular electrode implantable in the patient's heart for supplying ventricular stimulation pulses thereto, and at which a pulse appears in response to each ventricular contraction; separately switchable control paths connected to each electrode for causing one electrode to produce a stimulation pulse at a given time after the occurrence of a pulse on the other electrode; a first time delay unit connected to be actuated by signals derived from the heart behavior for supplying a stimulating pulse to the ventricular electrode at a time after the occurrence of a pulse on the atrial electrode, which is shorter than the physiological atrial-ventricular transfer time; and a second time delay unit connected to be actuated by signals derived from the heart behavior f

Abstract: A signal processing device composed of: a signal input for receiving an electrocardiographic signal containing a succession of QRS complexes; a signal output; a digitally operating unit having a transmission factor which is variable in discrete steps and connected between the signal input and output for supplying to the signal output a signal containing representations of the QRS complexes contained in the signal received by the signal input, with the relation between the amplitude of the signal at the signal output and the amplitude of the corresponding portions of the signal received by the signal input being proportional to the existing transmission factor of the digitally operating unit; and a transmission factor control unit connected to monitor the signal at the signal output for increasing the transmission factor of the digitally operating unit by one step in response to each appearance at the signal output of a QRS complex representation having a peak value between selected first and second threshold