The disclosure provides techniques for parameter-directed shifting of
electrical stimulation electrode combinations. An external programmer
permits a user to shift electrode combinations, e.g., along the length of
a lead or leads. The external programmer accepts shift input and causes
an electrical stimulator to shift electrode combinations as indicated by
the input. Different sets of electrodes may have different electrode
counts. For example, an array of electrodes carried by one lead may have
a greater number of electrodes than an array of electrodes carried on
another lead. The disclosure provides techniques for shifting electrode
combinations among leads with different electrode counts. For example, an
external programmer may execute shifts in a series of shift operations,
where the number of shift operations along the length of a lead having a
greater electrode count is greater than the number of shift steps along
the length of a lead having a lesser electrode count.