Patent ID: 8249717

Claim:
A method, comprising: generating a neural stimulation signal only during a duty cycle of a stimulation period to provide intermittent neural stimulation for a neural stimulation therapy, including: generating the neural stimulation signal during the duty cycle of the stimulation period to provide the neural stimulation therapy with an intensity at a therapy level for a portion of the duty cycle; and implementing a ramp up protocol to begin the duty cycle, a ramp down protocol to end the duty cycle, or both the ramp up protocol to begin the duty cycle and the ramp down protocol to end the duty cycle; wherein implementing the ramp up protocol includes stepping up the intensity from a zero value before the duty cycle when the neural stimulation signal is not generated to a non-zero first subthreshold level for the neural stimulation therapy at the beginning of the duty cycle and ramping up the intensity from the non-zero first subthreshold level at the beginning of the duty cycle to the therapy level; and wherein implementing the ramp down protocol includes ramping down the intensity from the therapy level to a non-zero second subthreshold level for the neural stimulation therapy at the end of the duty cycle, and stepping down the neural stimulation intensity from the non-zero second subthreshold level for the neural stimulation therapy at the end of the duty cycle to the zero value after the duty cycle when the neural stimulation signal is not generated.