Pain relief during childbirth is the hot point in the research of modern obstetrics. In the bedThe ideal outcome for parturient delivery is not only to have a quick onset,The function is strong and equal to special point, should have to mother and infant at the same time the shadow is small, to produce woman palaceContractile and move the shadow sound is small, avoid motion block happening, keep puerpera clear awakeIn order to improve the quality of peripartum