A Clinical Study on the Efficacy of Acupuncture Treatment in Essential Hypertension: Protocol for Randomized Controlled Trial - Xiaomin Hao; Lili Zhang; Yu Gong; Jun Wang; Weilan Qin; Xudong Zhang; Qiulei Guo; Meng Xu; Taotao Lv; Yan Guo; Yu Liu; Jipeng Liu; et al. (JMIR Research Protocols)