Patent ID: 8761875

Claim:
An apparatus, comprising: an implantable impedance sensor configured to deliver an impedance signal; an implantable capacitor stack disposed in a case and including a plurality of substantially flat electrodes in alignment, the stack including a first capacitor comprising a first partition of electrodes including a first anode and a first cathode, the first partition of a first capacitance to deliver a first pulse of a first amount of energy when discharged from a voltage, the stack including a second capacitor comprising a second partition of electrodes including a second anode and a second cathode, with an electrical insulator disposed between the first partition and the second partition, with the first anode electrically isolated from the second anode inside the case, the second partition to deliver a second amount of energy when discharged from the voltage; an electrolyte filling the case and contacting both the first partition and the second partition; implantable switch means for selectively switching the first capacitor and the second capacitor between a first mode for delivering a first preprogrammed level of pulse energy having a duration less than a first pulse duration limit, the first mode one in which the first capacitor is switched to discharge to a load while the second capacitor is switched out of electrical communication with the load, and a second mode for delivering a second preprogrammed level of pulse energy having a duration less than a second pulse duration limit, the second mode one in which the first capacitor and the second capacitor are adapted to discharge in parallel to the load; and a circuit coupled to the implantable impedance sensor and the implantable switch means, the circuit to select between the first mode and the second mode based on the signal of the impedance sensor, the first pulse duration limit and the second pulse duration limit.