A spinal cord stimulation (SCS) system includes multiple electrodes, multiple,
independently programmable, stimulation channels within an implantable pulse generator
(IPG) which channels can provide concurrent, but unique stimulation fields, permitting
virtual electrodes to be realized. The SCS system includes a replenishable power
source (e.g., rechargeable battery), that may be recharged using transcutaneous
power transmissions between antenna coil pairs. An external charger unit, having
its own rechargeable battery can be used to charge the IPG replenishable power
source. A real-time clock can provide an auto-run schedule for daily stimulation.
An included bi-directional telemetry link in the system informs the patient or
clinician the status of the system, including the state of charge of the IPG battery.
Other processing circuitry in the IPG allows electrode impedance measurements to
be made. Further circuitry in the external battery charger can provide alignment
detection for the coil pairs.
