摘要:
A cardiac assist system which provides simultaneous cardiac assistance during a confirmed cardiac arrythmia, but which provides for the inhibition of the cardiac assistance in the event battery voltage drops below a predefined point. In particular the present invention features a battery voltage safety limit during the deliver VF therapy state. During VF therapy state the system provides skeletal muscle stimulation while charging a defibrillation output capacitor. The battery voltage safety limit is set above a threshold which will insure proper device functionality, i.e. above the power-on-reset threshold (hereafter "POR"). If the battery voltage safety limit is reached the system inhibits the skeletal muscle stimulation to thereby avoid reaching the POR threshold, but yet still maintain the charging of the defibrillation output capacitor. Once charging of the defibrillation output capacitor is completed a synchronization routine is begun and defibrillation therapy is delivered. In such a manner the present invention prevents the dual demands of skeletal muscle stimulation along with charging of the defibrillation output capacitor to cause the battery voltage to collapse and drop below the power-on-reset threshold.
摘要:
A cardiac assist device having muscle augmentation after a confirmed arrhythmia. In particular the present invention operates, in a first embodiment, to sense a cardiac event, next it determines whether the cardiac event is a cardiac arrhythmia, if the event is not a cardiac arrhythmia the devices delivers stimulation to a skeletal muscle grafted about a heart, but if the event is a cardiac arrhythmia the device inhibits delivery of skeletal muscle stimulation and once the arrhythmia is confirmed, then delivers therapeutic stimulation to the heart. In a second embodiment the present invention operates to re-initiate skeletal muscle stimulation once the arrhythmia is confirmed but prior to the delivery of the therapeutic stimulation to the heart.
摘要:
A device and algorithm for a combined cardiomyostimulator and a cardiac pacer-cardioverter-defibrillator. In particular the present invention operates, in a first embodiment, to deliver stimulation to a skeletal muscle 3 grafted about a heart 2; sense depolarizations of a patient's heart; measure the intervals separating successive depolarizations of the patient's heart; define first and second interval ranges; determine the number of the measured intervals falling within the first and second interval ranges; inhibit the delivery of stimulation to a skeletal muscle grafted about a heart upon the sensing of a depolarization within the first or second interval range; detect the occurrence of a first type of arrhythmia when the number of the measured intervals falling within the first interval range equals a first predetermined value; detect the occurrence of a second type of an arrhythmia when the number of the intervals falling within the second interval range equals a second predetermined value; deliver a first type of arrhythmia therapy in response to the detection of the first arrhythmia; and deliver a second type of arrhythmia therapy in response to the detection of the second arrhythmia, the second type of arrhythmia therapy having a cardiac stimulation component and a skeletal muscle component.