System to estimate the location of a spinal cord physiological midline

A system comprising:

• one or more leads implantable in a patient, each of the one or more leads comprising one or more spinal electrodes;
• and
• an external device comprising a non-transitory computer-readable medium, comprising instructions, which when executed by a control circuitry of the external device, configure the control circuitry to:
• send instructions to a stimulation device to provide electrical stimulation at a first one or more peripheral electrodes that are positionable on a first side of an anatomical midline of the patient and to a second one or more peripheral electrodes that are positionable on a second side of an anatomical midline of the patient;
• receive data from the one or more leads that is indicative of a response at the one or more spinal electrodes to the electrical stimulation provided at the first and second one or more peripheral electrodes;
• and
• calculate, based on the received data, a ratio of the responses at the one or more spinal electrodes to the electrical stimulation provided at the first and second one or more peripheral electrodes, and
• calculate, based on the ratio, a measure of each of the one or more spinal electrodes' position with respect to a physiological midline.