Study on the Optimal Waveform Patterns of Electroacupuncture Targeted Intervention for Bell's Palsy Based on Surface Electromyography Characteristics

The goal of this clinical study is to find out whether different electronic acupuncture wave forms can effectively treat recovery-stage Bell's palsy in adults and evaluate their safety. The main questions it aims to answer are: * Can targeted electronic acupuncture wave forms improve facial nerve function in patients with Bell's palsy? * What is the optimal electronic acupuncture waveform for different degrees of facial nerve injury? * What adverse events may occur during electronic acupuncture treatment? Researchers will compare low-frequency continuous wave electronic acupuncture and intermittent wave electronic acupuncture to determine which waveform works better for recovery-stage Bell's palsy. Participants will: * Receive either low-frequency continuous wave electronic acupuncture or intermittent wave electronic acupuncture every other day for 4 weeks * Undergo surface sEMG and ENoG examinations at baseline, Week 2, and Week 4 * Complete facial function assessments and safety evaluations at each clinic visit