Manual acupuncture stimulation was applied to Baihui ( GV 20 ) , Zhongwan ( CV 12 ) , and bilateral Zusanli ( ST 36 ) , Sanyinjiao ( SP 6 ) , Yin-lingquan ( SP 9 ) and Fenglong ( ST 40 ) for 40 min , twice daily for 6 weeks except the weekends .