A Randomized, Double-Blind, Sham-Controlled Trial of Transcutaneous Auricular Vagus Nerve Stimulation as an Adjunct to General Anesthesia

INTERVENTION: Experimental group:Transcutaneous auricular vagus nerve stimulation;Control group:Transcutaneous vagus nerve pseudo stimulation; CONDITION: Laparoscopic surgery PRIMARY OUTCOME: The dosage of propofol during the induction period of anesthesia; SECONDARY OUTCOME: The cumulative dosage of analgesic drugs within 24 hours after the operation;The dosage of propofol and remifentanil during the maintenance period of anesthesia;Anesthesia depth monitoring indicators;Hemodynamic indicators;Quality indicators of awakening;NRS scores at each postoperative time point;Postoperative adverse events; INCLUSION CRITERIA: 1.Elective abdominal surgery under general anesthesia (including laparoscopic cholecystectomy, appendectomy, hernia surgery, etc.), with an estimated operation duration of 1 to 3 hours; 2.Age: 18 to 65 years old; 3.ASA physical status: Class ? to ?; 4.BMI: 18.5 to 28 kg/m^2; 5.Clear consciousness and normal communication capability; 6.Voluntary participation in this study with signed informed consent.