Method and apparatus for generating biphasic waveforms in an implantable defibrillator
First Claim
1. An implantable defibrillator apparatus electrically connected to at least two electrodes adapted for implantation in a human patient to treat cardiac dysrhythmia by delivering a biphasic countershock, the implantable defibrillator apparatus comprising:
- an implantable housing which contains;
sensing means for sensing a cardiac dysrhythmia in the human patient;
capacitor means for storing an electrical charge;
source means for charging the capacitor means to a charging voltage; and
control means for selectively controlling the power source means and the capacitive charge storage means in response to the sensing of the cardiac dysrhythmia to deliver a biphasic countershock to the at least two electrodes including;
means for controlling a first duration of a first phase of the biphasic countershock that has a first polarity such that the first duration is variable; and
means for controlling a second duration of a second phase of the biphasic countershock that has a second polarity that is opposite from the first polarity such that the second duration is fixed.
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Accused Products
Abstract
An implantable defibrillator system for generating biphasic waveforms comprises a self-contained human implantable housing containing a capacitor system for storing an electrical charge, a power supply for charging the capacitor system, and a controller for selectively discharging the electrical charge as a biphasic countershock to be delivered through at least two electrodes in response to a sensing of a cardiac dysrhythmia in the human patient. The controller includes a system for controlling a first duration of a first phase of the biphasic countershock such that the discharge of the electrical charge is of a first polarity and the first duration is variable and a system for controlling a second duration of a second phase of the biphasic countershock such that the discharge of the electrical charge is of a second polarity that is opposite from the first polarity and the second duration is fixed.
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Citations
30 Claims
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1. An implantable defibrillator apparatus electrically connected to at least two electrodes adapted for implantation in a human patient to treat cardiac dysrhythmia by delivering a biphasic countershock, the implantable defibrillator apparatus comprising:
an implantable housing which contains; sensing means for sensing a cardiac dysrhythmia in the human patient; capacitor means for storing an electrical charge; source means for charging the capacitor means to a charging voltage; and control means for selectively controlling the power source means and the capacitive charge storage means in response to the sensing of the cardiac dysrhythmia to deliver a biphasic countershock to the at least two electrodes including; means for controlling a first duration of a first phase of the biphasic countershock that has a first polarity such that the first duration is variable; and means for controlling a second duration of a second phase of the biphasic countershock that has a second polarity that is opposite from the first polarity such that the second duration is fixed. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An improved implantable defibrillator system for producing a biphasic capacitive-discharge countershock to be delivered through at least two electrodes adapted for implantation in a human patient, the implantable defibrillator system being a self-contained human implantable housing containing a waveform-generating capacitor means for storing an electrical charge, means for charging the waveform-generating capacitor means, and means for selectively discharging the electrical charge in the waveform-generating capacitor means as a biphasic countershock to be delivered through the at least two electrodes in response to a means for sensing of a cardiac dysrhythmia in the human patient, the improvement comprising:
the means for selectively discharging including; means for controlling a first duration of a first phase of the biphasic countershock such that the discharge of the electrical charge is of a first polarity and the first duration is variable and increases with an increase of a system time constant for the implantable defibrillator system; and means for controlling a second duration of a second phase of the biphasic countershock such that the discharge of the electrical charge is of a second polarity that is opposite from the first polarity and the second duration is variable and decreases with an increase of the system time constant for the implantable defibrillator system. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16)
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17. An improved implantable defibrillator system for producing a biphasic capacitive-discharge countershock to be delivered through at least two electrodes adapted for implantation in a human patient, the implantable defibrillator system being a self-contained human implantable housing containing a waveform-generating capacitor means for storing an electrical charge, means for charging the waveform-generating capacitor means, and means for selectively discharging the electrical charge in the waveform-generating capacitor means as a biphasic countershock to be delivered through the at least two electrodes in response to a means for sensing of a cardiac dysrhythmia in the human patient, the improvement comprising:
the means for selectively discharging including; means for controlling a first duration of a first phase of the biphasic countershock such that the discharge of the electrical charge is of a first polarity and the first duration is variable; and means for controlling a second duration of a second phase of the biphasic countershock such that the discharge of the electrical charge is of a second polarity that is opposite from the first polarity and the second duration is fixed. - View Dependent Claims (18, 19, 20, 21, 22, 23)
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24. A method for operating an implantable defibrillator device electrically connected to at least two electrodes adapted for implantation in a human patient to treat cardiac dysrhythmia by delivering a biphasic countershock, the method comprising the device-implemented steps of:
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(a) sensing for a cardiac dysrhythmia in a human patient; (b) in response to sensing the cardiac dysrhythmia, charging a capacitive charge storage system within the implantable defibrillator device to a charge value; (c) selectively discharging at least a first portion of the charge value stored in the capacitive charge storage system through the at least two electrodes to produce a first phase of the biphasic countershock, the first phase having a first polarity and a first duration that is variable; and (d) discharging at least a second portion of the charge value stored in the capacitive charge storage system through the at least two electrodes to produce a second phase of the biphasic countershock, the second phase having a second polarity that is opposite from the first polarity and having a second duration that is fixed. - View Dependent Claims (25, 26, 27, 28, 29, 30)
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Specification