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AssigneeTelectronics Pacing Systems, Inc.
InventorsTibor A. Nappholz, Saul E. Greenhut, Albert K. Dawson
Estimating the term…
A P-wave detector in a single chamber ventricular cardiac pacemaker, which is adapted to perform VDD pacing, senses natural atrial activity in the form of P-waves from a standard lead implanted in the ventricle of the heart. The P-wave detector is electrically coupled to a ventricular sensing lead and, although the electrode of the lead is implanted in the ventricle, circuitry within the pacemaker perceives intrinsic cardiac electrical activity arising from all parts of the heart. The P-wave detector is adapted to differentiate P-wave signals arising within the atrium from other cardiac and non-cardiac signals using template matching techniques in which an acquired signal is compared with a previously stored P-wave template.
A cardiac stimulating apparatus for implantation in a patient, comprising:
A cardiac stimulating apparatus for implantation in a patient, comprising:
A method of providing heart stimulating therapy to a patient's heart, comprising:
A cardiac stimulating apparatus for implantation in a patient, comprising:
A cardiac stimulating apparatus for implantation in a patient, comprising:
A cardiac stimulating apparatus for implantation in a patient, comprising:
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Heart stimulators: controlled by a physiological parameter, e.g. heart potential
Electrotherapy
Term ended 3 Feb 2012 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
This invention relates generally to cardiac pacemakers having a single lead implanted within the ventricle of the heart for stimulating heartbeats and sensing cardiac electrical signals, and more particularly to such pacemakers which analyze such cardiac electrical signals to distinguish atrial depolarizations (P-waves) arising remote from the ventricle, for the purpose of controlling ventricular stimulation timing.
In the heart, natural atrial electrical depolarization waves propagate from the sinus node through the atrium to the atrioventricular node to stimulate the ventricle. In some diseased hearts, the electrical conduction pathway breaks down, so that the sinus node triggers the electrical heartbeat process but the electrical impulse does not conduct to the ventricle.
Dual-chamber pacemakers adapt pacing rate and timing to a patient's needs by sensing natural atrial heartbeat signals (P-waves) and by generating electrical stimulating pulses in the ventricle in response to the timing of sensed P-waves. The ideal sensor for determining a proper pacing rate is a normally functioning sinus node. Physiologic pacemakers which employ atrial sensing in VDD and DDD pacing modes, as are standard in the art of pacemakers, are truly rate responsive. Dual-chamber pacing is an effective therapy for high degree atrioventricular block, particularly for patients in which the natural sinus (rate-determining) mechanism is intact and functioning normally. In such cases, the rate-determining response of the pacemaker to emotion or exertion is the same as that of the normal heart's rate-setting mechanisms. Thus, the pacemaker acts as an artificial atrioventricular conducting system to reestablish A-V synchrony.
FIG. 1 is a high-level block schematic which illustrates important functional blocks of a preferred embodiment of the invention as utilized in a VDD pacemaker which employs atrial sensing via a ventricular lead P-wave detector;
FIG. 2 is a highly schematic block diagram which illustrates the functional elements of a ventricular P-wave detector;
FIG. 3 is a flow diagram describing the operations of a pacing and sensing controller shown in FIG. 2;
The present invention is a pacemaker which is capable of performing VDD pacing (atrial-synchronized, ventricularinhibited pacing mode), a synchronous pacing mode in which the pacemaker delivers stimulation pulses only in the ventricle of the heart, but the pacemaker senses natural electrical activity in both the atrium and ventricle. Such a pacemaking operation creates a dual mode of response; sensed atrial events trigger ventricular stimulation while sensed ventricular events inhibit the delivery of ventricular stimulation pulses.
Referring to FIG. 1, a pacemaker, shown generally at 1, is coupled to a patient's heart 10 via a conventional bipolar lead 16 that is provided with conventional tip and ring electrodes (not shown). The fundamental requirements for pacemaker 1 include the ability to generate and deliver to the heart 10, at selected intervals, electrical stimulation pulses of varying amplitudes and forms.
All pacemaker 1 logic is under the control of controller 11 (which may include a microprocessor), which controls all of the other blocks of FIG. 1. In particular, the controller determines the amplitude and shape of the stimulating pulses and also sets the timing of pulse delivery. The controller also governs the timing and number of acquisitions of intracardiac electrogram samples in addition to determining and executing any signal filtering required for signal analysis. As the controller performs signal sampling, it carries out the analysis necessary for the diagnostic purposes of the device, as described below.