Effectiveness of a harmonica-integrated, tele-supervised home-based pulmonary rehabilitation program on lung function and comprehensive health outcomes in patients with chronic obstructive pulmonary disease: a randomized controlled trial protocol - Zeng, Qiuxuan; Lin, Xiaohong; Chen, Wenli; Fong, Daniel Yee Tak; Li, Junxin; Li, Jiaying (Frontiers in Public Health, 2025)