Analgesia by Single or Dual Acupoints Stimulation After Radical Mastectomy

Inclusion Criteria: * Scheduled for operation of breast cancer； * ASA（American Society of Anesthesiologists）I-II； * Aged between 18 and 65； * Informed consented。 Exclusion Criteria: * Suffered from the contraindication of TEAS including the local skin breakage, infection or planted with the electrophysiology device； * Unable to communicate and coordinate with the researcher, such as suffering from language comprehension deficits or mental diseases； * Certain/suspicious addiction with alcohol, analgesics or other drugs； * Unstable Angina or myocardial infarction occurred in 3 months; NYHA（New York Heart Association） is 3 or higher; * Blood pressure ≥ 180/110 mm Hg while preoperative visiting; * Suffered from diabetic complications including diabetic ketoacidosis, hyperosmolar coma, infection, macroangiopathy, diabetic nephropathy, retinopathy, cardiomyopathy, neuropathy and diabetic foot; * Severe dysfunction of liver or kidney meaning one of ALT（Alanine Transaminase）, AST（Aspartate Transaminase）, ALP（alkaline phosphatase） or TBIL（total bilirubin） is 2 times higher that normal or creatinine clearance \< 30 ml/min or serum creatinine \> 177umol/L; * Participate in the other clinical trial 3 month before the enrollment.