BreEStim Pre-trial

The overall goal is to evaluate the effectiveness of different stimulation protocol of a novel intervention - Breathing-controlled electrical stimulation (BreEStim) in managing neuropathic pain after spinal cord injury (SCI).

Inclusion Criteria (SCI subjects): * has a history of SCI \> 1 year; * has a DN4 (Douleur Neuropathique en 4 questions)\* score of 4 or greater; * has an average pain score of 4 or more * has neuropathic pain \>3 months; * is between 22 to 80 years of age; * is stable on oral pain medications at least one month (no change in frequency and dosing of pain medications); * is able to tolerate BreEStim treatment for 1 minute. Exclusion Criteria (SCI subjects): * is on a mechanical ventilator; * is currently having active urinary tract infection (UTI); * does not have any residual sensation in the arms; * has other pain (musculoskeletal, visceral etc.), but not neuropathic, e.g., shoulder pain from wheelchair use; * has a pacemaker (to avoid possible side effect of electrical stimulation); * is not able to follow commands, or to give consent; * has asthma or other pulmonary disease; * has a history of cardiac pathology, implanted pacemakers, or current use of rhythm altering medication like beta-blockers; * has a baclofen pump or deep brain implants; * has a respiratory tract/sinus infection and rhinorrhea; * has low motor neuron injury that no responses will be triggered by electrical stimulation; * has severe mental disorders (e.g., depression, substance abuse) and is receiving active treatment and frequent monitoring; * is not medically stable. * Pregnancy Inclusion criteria (healthy subjects): * healthy; * between 18-75 years old. Exclusion criteria (healthy subjects): * individuals with neuromusculoskeletal impairments/injury or pain; * women who are pregnant