I purchased the Equitonic 9 for use on horses. However, when my 51 year old son has difficulties breathing due to advanced Parkinson’s disease, we have found that by laying the unit on his chest he begins to breathe easier. His diaphragm is compromised due to muscle atrophy, and therefore, he is unable to move mucus out of his airways well. The unit helps break up the secretions and allows him to have a productive cough and clear his airways. He now sleeps with the unit every night for comfort and better sleep. We are grateful for the technology that assists him with these issues. By the way, the horses love it too.