Effect of TEAS on PONV After Spinal Surgery

Inclusion Criteria: * Male and female patients , 18 or older * American Society of Anesthesiologists (ASA) classification I or II or III * Undergoing elective spinal surgery expected to last no more than four hours (from induction of anesthesia to extubation). * Capable and willing to consent Exclusion Criteria: * Neuraxial (intrathecal or epidural) block * Significant ongoing history of vestibular disease or dizziness * Nausea or vomiting within 24 hours prior to surgery, use of antiemetic or emetogenic drugs within 3 days of surgery * Documented alcohol or substance abuse within 3 months before the surgery * Limb abnormalities such as burn and amputation. * Poorly controlled diabetes mellitus (fasting plasma glucose \>126 mg/dL or \<70 mg/dL) * Implantation of metal/electrical devices, such as nerve stimulator, cardiac pacemaker, cardioverter, defibrillator and internal hearing aids * Rash, local infection, keloid, any dermatologic condition that could interfere with the acupoint stimulation area * Documented alcohol or substance abuse within 3 months before surgery * Presence of clinically diagnosed major psychiatric condition such as bipolar disorder, uncontrolled major depression, or schizophrenia * Chemotherapy or radiation therapy within 7 days before surgery * Investigational product use within 3 months prior surgery * Any condition, which in the opinion of the investigator would make subject ineligible for participation in the study (history of unstable cardiovascular, pulmonary, renal, hepatic, seizures) * Special population (prisoners, pregnant and lactating women)