Apparatus for generating multiphasic defibrillation pulse waveform
First Claim
1. An apparatus for generating multiphasic defibrillation pulse waveforms by selectively switching the continuous output of a single multilevel source, comprising:
- first and second output terminal means for electrical connection to the heart;
a plurality of charge storage means forming a single multilevel source, each said storage means storing an electrical charge to provide an output potential;
low voltage power source means;
charging means connected to said plurality of charge storage means and said low voltage power source means for charging each of said charge storage means to a level suitable to cause defibrillation of the heart;
a plurality of switch means, each having control means operative to render the switch means conductive in response to a control signal, one switch means of said plurality being connected in circuit between a respective one of each said charge storage means and each of said first and second output terminal means for connecting the potential provided by the said charge storage means to the respective terminal means when said switch means is conductive sand disconnecting the potential provided by said charge storage means form the respective terminal means when said switch means is nonconductive; and
pulse generator means connected to said control means of said plurality of switch means for applying control signals to said control means upon said charge storage means reaching a predetermined level to thereby control the conductive state of each of said plurality of switch means to sequentially connect and disconnect said output potentials of said plurality of charge storage means to and from said first and second output terminal means in selected additive and subtractive combinations to generate a multiphasic defibrillation pulse waveform for application to the heart.
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Accused Products
Abstract
An apparatus suitable for use in an implantable automatic defibrillation system for automatically generating a multiphasic defibrillation pulse waveform in response to sensed fibrillation has first and second series charge-storing capacitors having a common terminal and two other terminals each at different potentials. A controller senses cardiac fibrillation and generates a control signal which causes a charging circuit to charge the capacitors to selected voltage levels in sequentially alternating charge generation and charge coupling cycles. A voltage level detector senses the stored voltage level, disables the charging circuit when the sensed voltage reaches a predetermined level, and informs the controller that the capacitors are fully charged. The controller then communicates control signals indicative of pulse magnitude, duration, and polarity to a multiphasic pulse generator having a number of high-power switches and corresponding switch drivers interposed in circuit between the heart and the terminals of the charge-storing capacitors. The drivers control the conduction states of the switches according to the control signals to establish selected circuit paths between the three terminals and the heart, and to thereby deliver to the heart a multiphasic waveform having pulses with the selected parameters of magnitude, duration, and polarity.
598 Citations
30 Claims
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1. An apparatus for generating multiphasic defibrillation pulse waveforms by selectively switching the continuous output of a single multilevel source, comprising:
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first and second output terminal means for electrical connection to the heart; a plurality of charge storage means forming a single multilevel source, each said storage means storing an electrical charge to provide an output potential; low voltage power source means; charging means connected to said plurality of charge storage means and said low voltage power source means for charging each of said charge storage means to a level suitable to cause defibrillation of the heart; a plurality of switch means, each having control means operative to render the switch means conductive in response to a control signal, one switch means of said plurality being connected in circuit between a respective one of each said charge storage means and each of said first and second output terminal means for connecting the potential provided by the said charge storage means to the respective terminal means when said switch means is conductive sand disconnecting the potential provided by said charge storage means form the respective terminal means when said switch means is nonconductive; and pulse generator means connected to said control means of said plurality of switch means for applying control signals to said control means upon said charge storage means reaching a predetermined level to thereby control the conductive state of each of said plurality of switch means to sequentially connect and disconnect said output potentials of said plurality of charge storage means to and from said first and second output terminal means in selected additive and subtractive combinations to generate a multiphasic defibrillation pulse waveform for application to the heart. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A cardiac defibrillator, comprising:
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first and second output terminal means for electrical connection to a heart; a plurality of charge storage means forming a single multilevel source of waveforms, each storage means storing an electrical charge to provide an output potential; low voltage power source means; charging means connected to said plurality of charge storage means and said low voltage power source means for charging said charge storage means; a plurality of switch means, each having control means operative to render the switch means conductive in response to a control signal, one said switch means of said plurality being connected in circuit between a respective one of each said charge storage means and each of said first and second output terminal means for connecting the potential provided by the said charge storage means to the respective terminal means when said switch means is conductive and disconnecting the potential provided by the said charge storage means from the respective terminal means when said switch means is non-conductive; pulse generator means connected to said control means of said plurality of switch means for applying control signals to said control means to thereby connect and disconnect said output potentials of said plurality of charge storage means to and from said first and second output terminal means to and from said first and second output terminal means in selected additive and subtractive combinations to generate a multiphasic defibrillation pulse waveform for application to the heart; means responsive to the onset of cardiac fibrillation for activating said charging means and; means responsive to the attainment by at least one of said charge storage means of a predetermined level of charge sufficient to defibrillate the heart for activating said pulse generator means. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. An electrical stimulator apparatus, comprising:
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first and second output terminal means for electrical connection to tissue to be stimulated; a plurality of charge storage means forming a single multilevel source, each said storage means storing an electrical charge to provide an output potential; low voltage power source means; charging means connected to said plurality of charge storage means and said low voltage power source means for charging said charge storage means; a plurality of switch means, each having control means operative to render the switch means conductive in response to a control signal, one switch means of said plurality being connected in circuit between a respective one of said charge storage means and each of said first and second output terminal means for connecting the potential provided by the said charge storage means to the respective terminal means when said switch means is conductive and disconnecting the potential provided by the said charge storage means from the respective terminal means when said switch means is non-conductive; pulse generator means connected to said control means of said plurality of switch means for applying control signals to said control means to thereby connect and disconnect said output potentials of said plurality of charge storage means to and from said first and second output terminal means in selected additive and subtractive combinations to generate a multiphasic pulse waveform for application to said tissue to be stimulated and lead means connected between said first and second output terminal means and the tissue to be stimulated. - View Dependent Claims (20)
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21. A cardiac defibrillator, comprising:
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a single source having a plurality of storage means for storing multilevel electrical charges;
means responsive to onset of fibrillation for initiating charging of said storing means;means for detecting the level of charge stored by said storing means to interrupt said charge upon attainment of a preselected level of stored charge; and means responsive to attainment of said preselected level for sequentially discharging said storing means with successive alternations of polarity over selected time intervals to generate a multiphasic pulse waveform having at least two successive electrical pulses of predetermined magnitude, duration, and opposite polarity sequence, with energy content sufficient for defibrillation, for delivery to the patient'"'"'s heart. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification