System and method for uniformly displacing a region of neural stimulation

A method of operating a tissue stimulation system, comprising:

• placing an array of electrodes in contact with tissue of a patient;
• conveying an electrical current within the electrode array, thereby creating a stimulation region in the tissue;
• and
• shifting electrical current between cathodes of the electrode array in incremental steps over a range in accordance with a sigmoid function of a position of the stimulation region, wherein the incremental steps at boundaries of the range are greater than the incremental steps at a center of the range.

A method of operating a tissue stimulation system, comprising:

• placing an array of electrodes in contact with tissue of a patient;
• conveying an electrical current within the electrode array, thereby creating a stimulation region in the tissue;
• accessing a navigation table containing a series of states and corresponding gradually and non-uniformly changing electrical current values, wherein differences between the electrical current values of adjacent states in the navigation table at boundaries of a range of states are greater than differences between adjacent electrical current values of adjacent states in the navigation table at a center of the range of states;
• and
• shifting electrical current between cathodes of the electrode array by incrementing through the states of the navigation table.