Implantable cardioverter defibrillators using high power amplifiers with impedance tracking lowpass filters

A controller for a cardiac device to treat a cardiac condition in a patient, which comprises:

• a microcontroller;
• a digital-to-analog converter (DAC);
• an analog to digital converter (ADC);
• and
• a waveform energy control system comprising differentially driven Class D and Class B amplifier sections, wherein the Class D amplifier section produces Phase 1 ascending waveforms and has a programmable impedance tracking lowpass filter (LPF) and wherein the Class B amplifier section delivers fast slew rate, hard-switched Phase 2 waveforms,
• wherein each of the Class D and Class B amplifier sections has an input and an output,
• wherein the microcontroller is operatively connected to the DAC, the DAC is operatively connected to each of the inputs of the Class D and Class B amplifier sections, the microcontroller is configured to respond to software commands to generate signals to the DAC, the DAC provides signals to the inputs of the Class D and Class B amplifier sections, and the outputs of the Class D and Class B amplifier sections deliver constant current, constant voltage, or constant energy ascending arbitrary waveforms or biphasic truncated exponential (BTE) waveforms for pacing, anti-tachycardia pacing (ATP), low-, medium-, or high-voltage therapy, cardioversion or defibrillation electrical shocks to the patient's heart or for providing a late systolic electrical impulse to stimulate the intraventricular septum and bundle branches of the patient's heart to increase the heart's ejection fraction.