Ventilation Function

The aim of this study is to observe the effect of adjustable headrests on ventilation function in overweight and obese patients through clinical experiments, and to explore the impact on the incidence of hypoxemia during painless curettage in overweight and obese patients. Participants will be randomly allocated to three groups: the supine head-straight position group(Group A), the supine head-lateral position group(Group B), and the adjustable headrest group(Group C). These three groups of patients underwent painless curettage surgery in the daytime operating room and the occurrence of hypoxemia will be observed.