RT Journal Article SR Electronic T1 A Hands-Free, Oral Positive Expiratory Pressure Device for Exertional Dyspnea and Desaturation in COPD JF Respiratory Care FD American Association for Respiratory Care SP 408 OP 412 DO 10.4187/respcare.10278 VO 68 IS 3 A1 Muhammad Ahsan Zafar A1 Ashley Cattran A1 Rachel Baker A1 Roman Jandarov A1 Ralph J Panos YR 2023 UL http://rc.rcjournal.com/content/68/3/408.abstract AB