Patent ID: 8868178

Claim:
An electrotherapy apparatus adapted for subcutaneous implantation for applying far-field pacing therapy for treating a patient experiencing an arrhythmia, the apparatus comprising: a power source adapted to supply energy for operation of the apparatus; electrotherapy administration circuitry electrically coupled to the power source and to a set of patient terminals, and constructed to generate electrotherapy pulses using the energy from the power source and apply a series of the electrotherapy pulses via the patient terminals in response to a control signal, the electrotherapy pulses being far-field pacing pulses, each delivering sufficient charge, through a set of electrodes positioned subcutaneously in far-field fashion relative to a heart of the patient, to initiate a cardiac cycle; monitoring circuitry electrically coupled with the power source and the set of patient terminals, and constructed to monitor the patient for indicia of the arrhythmia; controller circuitry electrically coupled with the power source, the electrotherapy administration circuitry, and the monitoring circuitry, the controller circuitry including a processor and a data storage device containing instructions that, when executed by the processor, cause the controller circuitry to read an output of the monitoring circuitry and determine any presence of the arrhythmia based on that output, and to generate the control signal causing the electrotherapy administration circuitry to apply the series of electrotherapy pulses; wherein the electrotherapy administration circuitry includes a pulse shaping circuit constructed such that, in operation, the pulse shaping circuit applies a variable slew rate limit on to rising edge of each pulse to have a relatively faster slew rate for an initial portion of the rising edge and a relatively slower slew rate for a latter portion of each rising edge.