Apparatus for reducing polarization potentials in a pacemaker
First Claim
1. In a heart stimulator having a source of supply voltage, timing circuit means for providing first and second time intervals, a pair of output electrodes for applying a stimulating pulse to heart tissue, and an output capacitor coupled to one of said output electrodes, the improvement for attenuating polarization currents/voltages at said output electrodes comprising:
- first means for coupling said supply voltage source to said output capacitor during said first time interval for charging said output capacitor to a certain voltage;
second means for coupling said output capacitor to both of said output terminals during said second time interval to discharge said output capacitor voltage into, and thereby stimulate heart tissue; and
resistor means coupled across said output electrodes for providing a current path for the discharging of the effective capacitance of previously stimulated heart tissue and the charging of said output capacitor during said first time interval, said resistor means having a resistance sufficiently low to discharge said effective capacitance.
1 Assignment
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Accused Products
Abstract
A method and apparatus embodied in a pacemaker for attenuating polarization currents or voltages at the output terminals of the pulse generator. A heart pacemaker typically possesses a source of supply voltage, an output capacitor, an output terminal adapted to be coupled to heart tissue. A voltage source is coupled to the output capacitor during a first time interval for charging the output capacitor to a certain voltage. The output capacitor is coupled to the output terminals during a second time interval to discharge its voltage into the heart tissue. A resistor is coupled across the output terminals for providing a current path for the discharging and recharging of the effective capacitance of the stimulated heart tissue. The resistor may be coupled across the output terminals only during the first time interval and not during the discharge of the output capacitor.
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Citations
16 Claims
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1. In a heart stimulator having a source of supply voltage, timing circuit means for providing first and second time intervals, a pair of output electrodes for applying a stimulating pulse to heart tissue, and an output capacitor coupled to one of said output electrodes, the improvement for attenuating polarization currents/voltages at said output electrodes comprising:
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first means for coupling said supply voltage source to said output capacitor during said first time interval for charging said output capacitor to a certain voltage; second means for coupling said output capacitor to both of said output terminals during said second time interval to discharge said output capacitor voltage into, and thereby stimulate heart tissue; and resistor means coupled across said output electrodes for providing a current path for the discharging of the effective capacitance of previously stimulated heart tissue and the charging of said output capacitor during said first time interval, said resistor means having a resistance sufficiently low to discharge said effective capacitance. - View Dependent Claims (2, 3, 4, 5)
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6. An atrial and ventricular cardiac pacemaker pulse generator comprising:
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a source of supply voltage; atrial and ventricular output terminals adapted to be electrically coupled through respective atrial and ventricular pacing leads and electrodes to make electrical contact with atrial and ventricular heart tissue, respectively; atrial and ventricular timing circuit means for providing first and second time intervals; atrial and ventricular output circuits coupled to said output terminals and said timing circuit means, each respective output circuit further comprising; an output capacitor coupled to one of said output terminals; first means for coupling said supply voltage source to said output capacitor during said first time interval for charging said output capacitor to a certain voltage; and second means for coupling said output capacitor to both of said output terminals during said second time interval to discharge said output capacitor voltage into, and thereby stimulate, heart tissue; resistor means coupled across said output terminals of said ventricular output circuit for providing a current path for the discharging of the effective capacitance of previously stimulated heart tissue and the charging of the ventricular output capacitor during said first time interval, said resistor means having a resistance sufficiently low to discharge said effective capacitance; and control circuit means for controlling the synchronized application of said first and second time intervals to said atrial and ventricular output circuits. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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13. An atrial and ventricular cardiac pacemaker pulse generator comprising:
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a source of supply voltage; atrial and ventricular output terminals adapted to be electrically coupled through respective atrial and ventricular pacing leads and electrodes to make electrical contact with atrial and ventricular heart tissue, respectively; ventricular sense amplifier means having input terminals coupled across said ventricular output terminals for sensing electrocardiograms of the heart due to spontaneous and evoked depolarizations of the heart; atrial and ventricular timing circuit means for providing first and second time intervals; atrial and ventricular output circuits coupled to said output terminals, each respective output circuit further comprising; an output capacitor coupled to one of said output terminals; first means for coupling said supply voltage source to said output capacitor during said first time interval for charging said output capacitor to a certain voltage; and second means for coupling said output capacitor to both of said output terminals during said second time interval to discharge said output capacitor voltage into, and thereby stimulate, heart tissue; resistor means coupled across said output terminals of said ventricular output circuit for providing a current path for the discharging of the effective capacitance of previously stimulated heart tissue, said resistor means having a resistance sufficiently low to discharge said effective capacitance and sufficiently high to maintain satisfactory sensing by said ventricular sense amplifier means; and control circuit means for controlling the synchronized application of said first and second time intervals to said atrial and ventricular output circuits. - View Dependent Claims (14, 15, 16)
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Specification