IMPEDANCE-BASED ALLOCATION OF ELECTRICAL STIMULATION TO ELECTRODE CLUSTERS

Electrical stimulation sources and amplitudes are allocated to implantable electrodes based on impedance values for controlled delivery of electrical stimulation therapy to a patient. Allocation may include assigning implantable electrodes, in a group of active electrodes, to clusters based on impedance values of the electrodes, coupling the electrode clusters to respective stimulation sources, and defining respective stimulation amplitudes delivered by the stimulation sources to the electrode clusters. Each cluster may include electrodes having relatively similar impedance values, such that electrodes in each cluster present less variation in impedance relative to impedance variation across the group of electrodes. With reduced variation in impedance, in some examples, variation in current outflow through electrodes in each cluster may be reduced, promoting more uniform distribution of stimulation current across the group of active electrodes and a more uniform stimulation field.