Current truncated waveform defibrillator
AssigneeAngeion Corporation
InventorMark W. Knoll
Life of this patent
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Abstract
A system and method is provided for implantable cardioverter defibrillators to truncate peak current output during defibrillation countershock therapy to a safe level irrespective of the resistance of the myocardium between the discharge electrodes implanted within the heart.
Claims16
A method for operating an implantable device electrically connected to two or more implanted discharge electrodes located in a human patient to treat a myocardial fibrillation, the method comprising the device-implemented steps of:
- (a) sensing a myocardial fibrillation in the human patient;
- and
- (b) in response to the myocardial fibrillation,
- (b1) charging a charge storage system to a voltage;
- (b2) discharging a current from the charge storage system through the two or more implanted electrodes to generate a defibrillation countershock;
- and
- (b3) truncating the discharge of the current to truncate a peak current of the defibrillation countershock to less than a predetermined amount regardless of an effective resistance value into which the defibrillation countershock is discharged.
An implantable cardioverter defibrillator apparatus, the implantable cardioverter defibrillator apparatus being a self-contained human implantable device for treating cardiac arrhythmias that is electrically connected to at least two implanted discharge electrodes located in a human patient, the at least two implanted discharge electrodes having an effective resistance that is variable dependent upon the at least two implanted electrodes defining a discharge pathway therebetween and a physiological condition of the human patient across the discharge pathway, the apparatus comprising:
- (a) storage means electrically connected to the two or more implanted electrodes for storing an electrical charge to be delivered to the two or more implanted electrodes;
- (b) sensing means for sensing a cardiac arrhythmia in the human patient;
- (c) power source means for charging the storage means to a voltage;
- and
- (d) discharge means for selectively discharging the storage means in response to the sensing of the cardiac arrhythmias to deliver the electrical charge as a countershock that is current truncated such that the countershock has a peak current less than a predetermined amount regardless of the effective resistance value of a discharge pathway into which the countershock is delivered.
Dependencies are inferred from the claim text.