Implantable cardiac defibrillator with current leakage detecting means
First Claim
1. An implantable cardiac defibrillator which comprises:
- an energy source;
energy storage means;
means coupled to said energy source for charging said energy storage means;
means for coupling said energy storage means to a patient'"'"'s heart, for delivering a high voltage shock to the heart;
means for detecting current leakage to the patient from said energy storage means; and
means responsive to said detecting means for altering the charging of said energy storage means if the current leakage exceeds a predetermined amount.
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Accused Products
Abstract
An implantable cardiac deibrillator is provided having a battery, capacitive means, means coupled to the battery for charging the capacitive means, and means for coupling the capacitive means to a patient'"'"'s heart, for delivering a high voltage shock to the heart. Current leakage from the capacitive means is detected. If the current leakage exceeds a predetermined amount, charging of the capacitive means is terminated. In one embodiment, voltage at the patient is directly sensed. In another embodiment, the voltage across a resistance located in series with the patient is sensed. In another embodiment, a test charge is provided for a short interval. The capacitive means is sensed to determine excessive loss of energy after the test charge. If excessive loss of energy is determined, charging is terminated.
80 Citations
17 Claims
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1. An implantable cardiac defibrillator which comprises:
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an energy source; energy storage means; means coupled to said energy source for charging said energy storage means; means for coupling said energy storage means to a patient'"'"'s heart, for delivering a high voltage shock to the heart; means for detecting current leakage to the patient from said energy storage means; and means responsive to said detecting means for altering the charging of said energy storage means if the current leakage exceeds a predetermined amount. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An implantable cardiac defibrillator which comprises:
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an energy source; energy storage means; means coupled to said energy source for charging said energy storage means; means for coupling said energy storage means to a patient'"'"'s heart for delivering a high voltage shock to the heart; means for detecting current leakage to the patient from said energy storage means; means responsive to said detecting means for altering the charging of said energy storage means if the current leakage exceeds a predetermined amount; means for providing a test charge for a short interval, said detecting means comprising means for sensing said energy storage means to determine excessive loss of energy after said test charge; said test charge providing means comprising means for providing the test charge for a period shorter than the natural refractory period of the heart; means for synchronizing charging of said energy storage means to a sensed cardiac event; and means for reporting status.
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13. An implantable cardiac defibrillator which comprises:
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a battery; capacitive means; means coupled to said battery for charging said capacitive means; means for coupling said capacitive means to a patient'"'"'s heart for delivering a high voltage shock to the heart; means for synchronizing charging of said capacitive means to a sensed R-wave; means for detecting current leakage to the patient from said capacitive means; means responsive to said detecting means for altering the charging of said capacitive means if the current leakage exceeds a predetermined amount; said altering means comprising means for comparing a representation of the output from said detecting means to a reference voltage and for altering the charging of said capacitive means if the comparison indicates a fault.
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14. A method for operating an implantable cardiac defibrillator having an energy source, energy storage means, means coupled to said energy source for charging said energy storage means, and means for coupling said energy storage means to a patient'"'"'s heart, including the steps of:
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detecting current leakage to the patient from said energy storage means; and altering the charging of said energy storage means if the current leakage exceeds a predetermined amount. - View Dependent Claims (15)
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16. A method for operating an implantable cardiac defibrillator having an energy source, energy storage means, means coupled to said energy source for charging said energy storage means, means for coupling said energy storage means to a patient'"'"'s heart, including the steps of:
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providing an external command to provide a test charge to said energy storage means for a short interval; performing a first measurement of the voltage on the energy storage means; at a predetermined time thereafter, performing a second measurement of the voltage on the energy storage means; if the first voltage measurement exceeds the second voltage measurement by a predetermined amount, then altering the operation of said charging means. - View Dependent Claims (17)
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Specification