Patent ID: 8121680
Filing Date: 2012-02-21
Classification: A61N

Abstract:
1. An implantable subcutaneous cardiac device comprising: at least two subcutaneous electrodes adapted for placement near a heart but neither in nor on a heart and not in a vein associated with the heart; and a pulse generator that delivers a pacing pulse to the subcutaneous electrodes, the pacing pulse having a waveform consisting of a positive phase devoid of any exponential voltage decay and a negative phase devoid of any exponential voltage decay, wherein the positive phase initiates at a baseline voltage and includes a first portion curving away from the baseline voltage toward a peak voltage and a second portion curving along its entire length away from the peak voltage back to the baseline voltage, wherein the baseline voltage is the voltage level at which the positive phase transitions to the negative phase; wherein the positive phase and the negative phase are each defined by a rounded waveform having a width and a peak voltage, the peak voltage of the rounded waveform defining the positive phase is greater than the peak voltage of the rounded waveform defining the negative phase, and the width of the rounded waveform defining the positive phase is less than the width of the rounded waveform defining the negative phase.