Randomization and blinding
SPSS 25.0 software was used to randomize groups. The study subjects were numbered one by one according to the order in which they were enrolled, with the time of the start of the experiment 202,110 (October 2021) as the random number seed. Random numbers are generated using Rv. Uniform function in the SPSS random number generator and then grouped using the SPSS Visual Binning feature. Since this study was a controlled trial randomized into 2 groups, the number of split points was 1, and then 42 patients were randomly divided into Group 1 and Group 2.Regarding blinding, each subject’s grouping result was written in an opaque and sealed envelope, with the subject’s chronological inclusion number (1–42) on the outside of the envelope, and given to the TEAS operator. This random process was completed by a person who was not involved in the study. After the patient entered the operating room, TEAS was performed by the TEAS operator according to the contents of the envelope. If the envelope contained “1,” the placebo-type Han’s acupoint nerve stimulator was used, and if the envelope contained “2,” the therapeutic Han’s acupoint nerve stimulator was used. TEAS operators knew the contents of the envelopes but did not know the significance of the numbers; the TEAS operators were independent of this study and only administered the TEAS treatment. There was no communication about this study with patients, surgeons, anesthesiologists, or data analysts.