Abstract: The apparatus for pacing a heart in accordance with the heart rate needed to produce a required cardiac output while the person is exercising, comprises a pacer adapted to be implanted in a human body and having a pulse generator and control circuitry (e.g. including a microprocessor) therein, a pacing lead adapted to be implanted in a right ventricle in a heart and having a distal electrode adapted to engage and supply pacing pulses to the apex of the right ventricle and a pressure sensor or impedance sensing electrode mounted in or on the lead.

Abstract: A cardiac pacer which generates pacing pulses at a predetermined pacing rate includes a device for making a body activity measurement. The measured body activity signal is non-linearly amplified such that signal portions having higher amplitudes are more amplified than signal portions having lower amplitudes. The non-linearly amplified body activity signal is integrated over a period of time. The predetermined pacing rate is varied dependent on the integrated signal.

Abstract: A multi-functional radio/wire stethoscopic apparatus includes: a housing unit having a plurality of control switches and sockets provided therein for hand operation; a radio wave transmitting device and a wire transmission line disposed in the housing unit for signal transmitting operations; an audio-wave guiding device positioned on top of the housing unit for receiving sound waves; a plurality of microphones disposed in the audio-wave guiding device and electrically connected to the radio wave transmitting device and the wire transmission line; an upper casing detachably connected to the housing unit; and a chest piece with sound detecting arrangement functionally connected to an upper end of the upper casing; thereby, during auscultation and bed-side teaching, sound waves from a patient's body will be converted into electrical signals and transmitted for facilitating correct diagnosis through a radio/recorder set and an interface of audio wave control device electrically connected to the housing unit.

Abstract: A cardiac pacer, which generates pacing pulses at a predetermined basic pacing rate, includes a multiplicity of body activity sensors for sensing body activity dependent on different physiological variables and monitors for generating a corresponding body activity output signal dependent thereon. The predetermined basic pacing rate is then varied dependent on the body activity output signals.

Abstract: A passive stabilizer for an electrode lead of a cardiac pacemaker for maintaining the electrode tip in interstitial contact with the endocardium until a sufficient amount of tissue ingrowth has occurred to secure the electrode tip in place. The passive stabilizer is secured to the lead of the cardiac stimulating device adjacent the electrode tip and comprises a sleeve having at least two groups of resilient tines, each group of tines being longitudinally displaced along the axis of the conductive lead with a first group being disposed between the second group and the electrode tip. The tines extend radially outwardly from the lead at a substantially right angle, with the tines of the first group extending outwardly a distance less than that of tines of the second group. Additionally, the tines of the first group are circumferentially staggered with respect to the tines of the second group.

Abstract: An atrium controlled heart pacemaker has a switching stage which is controlled in dependence upon the appearance of atrial signals. The switching stage switches the heart pacemaker to a VVI mode for a predetermined number of stimulation pulses or natural ventricular events, or a predetermined time, upon the appearance of at least one atrial signal before a selected time limit. The time limit is derived from the difference between a smallest synchronous interval and the AV delay.

Abstract: A child calming device comprising, in accordance with the preferred embodiment, a stuffed animal (10) having a pocket (88) within which is contained a heart beat simulating transducer (12) is disclosed. The transducer is actuated by application of pressure to an actuator (22) which is coupled to a switch (30) which drives an electronic circuit (40) contained within the housing (14) of the simulator (12). The power of the "simulated" heart beats may be regulated by adjustment of a potentiometer via a knurled knob (98).

Abstract: An implantable pacemaker which stores in memory the representation of an ECG signal by compressing the data. Whenever the input signal changes by a threshold amount from the last time data was recorded, a representation of the time interval which has elapsed is recorded. In a maximimally efficient system, the only information which must be stored are the successive elapsed times, along with indications of when the input signal changes slope.

Abstract: A battery test circuit for a heart pacemaker has a stimulation pulse counter and input logic which identify the consumed charge from the operating values of the pacemaker, from the number of stimulation pulses emitted, and from a time-dependent base value. The consumed charge identified in each test is summed in a charge counter. The content of the charge counter is accordingly a measure for the total charge consumed.

Abstract: An atrium-controlled heart pacemaker operates using set parameters including a smallest synchronous interval (SSI) between two stimulation pulses, a minimum atrial-ventricular delay time (AVmin) and a maximum atrial-ventricular delay time (AVmax). A control unit, dependent upon the appearance of an atrial signal, controls operation of the pacemaker such that the pacemaker operates with a variable pulse rate (DDD mode) when the atrial signal appears after a point in time SSI-AVmin, operates the pacemaker with a highest synchronous pulse rate when the atrial signal is between the points in time SSI-AVmin and SSI-AVmax, and causes no stimulation pulses to be emitted when the atrial signal appears before the point in time SSI-AVmax.

Abstract: An implantable pacemaker in which the sensitivity is automatically controlled. The peak value of each R wave is measured, and a long-term average is derived. The gain of the sense channel is adjusted automatically in accordance with the average of the measured peak values.

Abstract: The spatial closed signal pattern is represented by measured signals picked up from a living being by means of electrodes. Sequences of consecutive spatial slope values are formed for each spatial closed signal pattern and different such sequences associated with different spatial closed signal patterns are mutually correlated. As a result of such correlation, the sequences are classified according to different classes and there is determined a temporal offset between such sequences. Minimum spatial slope values respectively associated with the starting region and the end region of each sequence are determined for each class. Predetermined time intervals about the moments of time which are associated with such minimum spatial slope values, are investigated for those sampling moments of time associated with the measured data having the smallest mutual spatial distance.

Abstract: A system and method for minimizing time-base fluctuations in playing back an electrocardiogram recorded on one track of a multi-track magnetic tape with reference clock signals recorded on another track. A sampling circuit samples the recorded electrocardiogram in response to sampling pulses produced in response to the recorded reference clock signals, and the sampled electrocardiogram is stored in a memory. The stored signal is then read in response to timing pulses produced by a generator. The phase difference between the sampling and timing pulses is detected and maintained constant.

Abstract: A battery test circuit for a heart pacemaker generates a signal which corresponds to the charge status of the pacemaker battery which is displayable in a manner which does not interfere with the normal pacing frequency of the pacemaker. A marking pulse is generated by the circuit at a chronological position between successive stimulation pulses which is dependent upon the charge status of the battery at the time the marking pulse is generated.