medium frequency electrotherapy

例句：

1. 1. This medium-frequency electrotherapy device can effectively treat chronic back pain.
   这种中频电疗设备可以有效治疗慢性背痛。
2. 2. The patient was treated with medium-frequency electrotherapy for several weeks before recovery.
   患者在接受中频电疗治疗后几周后康复。
3. 3. The doctor used medium-frequency electrotherapy to relieve the patient's muscle tension.
   医生使用中频电疗来缓解患者的肌肉紧张。