Prior to market release, the expected longevity is established. Expected longevity is established by statistically characterizing the power consumed by the device and the power available from the device battery. This characterization is applied to a number of parameter configurations. For each parameter configuration, the statistical mean value minus three standard deviations is used as the expected longevity for determining if a battery depleted normally at those parameters.
The estimated longevities provided here are for the specifc device settings and use conditions described in the footnote. The actual longevity achieved for any device while implanted will depend on the actual programmed parameters and patient factors, and may differ significantly from these estimates.