Non-acupoints were located about 1-2 cm beside the Baihui ( GV 20 ) , Danzhong ( CV 17 ) , Qihai ( CV 6 ) , Guanyuan ( CV 4 ) , Zusanli ( ST 36 ) , Taichong ( LR 3 ) , Sanyinjiao ( SP 6 ) and Hegu ( LI 4 ) .