A Review of Abdominal Muscle Stimulation for Patients with Spinal Cord Injury

[Purpose] Abdominal muscle stimulation can provide respiratory support in Spinal cord-injury patients. Stimulation may be applied by simple surface stimulation, resulting in uniform muscle contraction which can help to improve the expiratory function for coughing and breathing. [Subjects and Methods] In this review, an overview of methods and approaches available for abdominal muscle stimulation is given. Studies are discussed which show that this technique can lead to improvements in expiratory flow and tidal volume, resulting in enhanced cough and breathing functions. Approaches are introduced which aim to integrate abdominal stimulation with the subject's own voluntary breathing functions. These are illustrated with experimental results from the evaluation of automatic stimulation methods in tetraplegic patients.[Results]The results show that the effectiveness of abdominal surface stimulation can vary widely between subjects. [Conclusions] Clinical significance and applications are discussed and future developments and the direction of research in this area are reviewed.