Output pulse artifact rejection in demand pacemakers
First Claim
1. A heart pacemaker comprising:
- terminal means for connection to a patient'"'"'s means for delivery atrial and ventricular stimulation thereto;
generating means for delivering sequential atrial and ventricular electrical stimulation pulses to said terminal means at a predetermined repetition rate;
a sensing amplifier for sensing electrical signals indicative of the patient'"'"'s heartbeat;
blanking means for normally connecting said terminal means to said sensing amplifier for conveying the patient'"'"'s heartbeat signals thereto, and for selectively decoupling said sensing amplifier from said terminal means during delivery of an atrial stimulation pulse, said blanking means including holding circuit means operative during a blanking interval to hold a prior signal level at the input to the sensing amplifier, and timing means for sequentially returning the blanking means and the holding means to normal operation at the end of the atrial stimulation pulse.
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Accused Products
Abstract
An atrial-ventricular demand pacemaker having improved atrial pulse artifact rejection includes a blanking circuit (30, 100) connected in the signal path from the ventricular output terminal (17) to the sensing amplifier (21) to blank the signal during an atrial pulse. A holding circuit including a low-pass filter (46, 137) and a switching element (43, 112) stores a prior signal value at the sensing amplifier input during the blanking interval, and delays return to normal operation until after the blanking circuit has returned to normal. Artifact rejection is also improved by limiting atrial pulse output circuit recharge time and by limiting polarization current driven into the ventricular output circuitry by an atrial output pulse.
27 Citations
8 Claims
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1. A heart pacemaker comprising:
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terminal means for connection to a patient'"'"'s means for delivery atrial and ventricular stimulation thereto; generating means for delivering sequential atrial and ventricular electrical stimulation pulses to said terminal means at a predetermined repetition rate; a sensing amplifier for sensing electrical signals indicative of the patient'"'"'s heartbeat; blanking means for normally connecting said terminal means to said sensing amplifier for conveying the patient'"'"'s heartbeat signals thereto, and for selectively decoupling said sensing amplifier from said terminal means during delivery of an atrial stimulation pulse, said blanking means including holding circuit means operative during a blanking interval to hold a prior signal level at the input to the sensing amplifier, and timing means for sequentially returning the blanking means and the holding means to normal operation at the end of the atrial stimulation pulse.
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2. A heart pacemaker comprising:
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terminal means for connection to a patient'"'"'s heart for delivering atrial and ventricular stimulation thereto; generating means for delivering sequential atrial and ventricular electrical stimulation pulses to said terminal means at a predetermined repetition rate; a sensing amplifier for sensing electrical signals indicative of the patient'"'"'s heartbeat; demand control means connected to said sensing amplifier and operative for preventing delivering of said stimulating pulses if a heartbeat occurs within a predetermined time interval following a preceding heartbeat; means for providing a signal path from said terminal means to said sensing amplifier, said signal path means including a first switching means for selectively preventing the passage of signals along the signal path; signal holding means including a capacitor connected to said signal path means between said switching means and the sensing amplifier, and a second switching means operatively connected to selectively isolate said capacitor from said signal path and said first switching means and to thereby hold a prior signal at the input of said sensing amplifier; and timing means operatively connected for actuating said first and second switching means during delivery of an atrial pulse to block said signal path and hold a prior signal at said sensing amplifier, whereby atrial pulse artifact is prevented from entering the sense amplifier. - View Dependent Claims (3, 4, 5, 6)
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7. A heart pacemaker comprising:
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terminal means for connection to a patient'"'"'s heart for delivering atrial and ventricular stimulation thereto; generating means for delivering sequential atrial and ventricular electrical stimulation pulses to said terminal means at a predetermined repetition rate; a sensing amplifier for sensing electrical signals indicative of the patient'"'"'s heartbeat; demand control means connected to said sensing amplifier and operative for preventing delivery of said stimulating pulses if a heartbeat occurs within a predetermined time interval following a preceding heartbeat; blanking means for normally connecting said terminal means to said sensing amplifier for conveying the patient'"'"'s heartbeat signals thereto, and for selectively decoupling said sensing amplifier from said terminal means during delivery from said terminal means during delivery of an atrial stimulation pulse, said blanking means including holding circuit means operative during a blanking interval to hold a prior signal level at the input to the sensing amplifier. - View Dependent Claims (8)
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Specification