초록 ▼

Method of and apparatus for automatic defibrillation of the cardiac ventricles of a heart wherein both the mechanical and electrical activities of the ventricles are sensed and used as operating inputs to the controls. Electrical activity is detected and measured with a pair of electrodes, and the w

Method of and apparatus for automatic defibrillation of the cardiac ventricles of a heart wherein both the mechanical and electrical activities of the ventricles are sensed and used as operating inputs to the controls. Electrical activity is detected and measured with a pair of electrodes, and the waves of an electrocardiogram (ECG) are analyzed. When such electrical analysis indicates that ventricular fibrillation is present and persists, an electrical circuit is actuated for detecting mechanical pumping activity of the heart. Mechanical pumping activity is measured by the change in impedance between the pair of electrodes in one of the ventricles. The change of ventricular impedance is caused by the varying volume of blood contained within the ventricle and depends upon whether the ventricle is in a contracted or a relaxed state. The defibrillator is actuated only when both the mechanical and electrical activity of the ventricle indicates a need for defibrillation. Because some conditions may be encountered which closely resemble ventricular fibrillation, the defibrillator quantitatively preprograms and weighs the relative importance of the electrical and mechanical signals from the heart.

대표청구항 ▼

An automatic cardiac ventricular defibrillator comprising: means for sensing electrical and mechanical activity of a cardiac ventricle in the form of ECG analog signals and the impedance of the ventricle, an ECG analog processor for producing an ECG analog processor signal of a fibrillatory conditio

An automatic cardiac ventricular defibrillator comprising: means for sensing electrical and mechanical activity of a cardiac ventricle in the form of ECG analog signals and the impedance of the ventricle, an ECG analog processor for producing an ECG analog processor signal of a fibrillatory condition, means for communicating the sensed electrical activity to said ECG analog processor, accumulator-control-logic means for counting fibrillatory signals, means for communicating an ECG analog processor signal of a fibrillatory condition from said ECG analog processor to said accumulator-control-logic means, an impedance analog processor operatively connected to said sensing means and responsive to said accumulator-control-logic means and for developing a signal of a non-fibrillatory condition which effects a decrementing count, means for communicating an activation switching action to said impedance analog processor responsively to a predetermined number of counted fibrillatory signals to selectively activate said impedance analog processor, means for communicating impedance measurement of the ventricle to said impedance analog processor, means for communicating an impedance analog processor derived signal of a non-fibrillatory condition to said accumulator-control-logic means while the impedance analog processor is activated, said accumulator-control-logic means being thereafter simultaneously responsive to both ECG analog processor and impedance analog processor signals, and an energy delivery system responsive to said accumulator-control-logic means to effect a defibrillating electrical shock to the heart appropriate to the correction of a fibrillatory heart condition.