Inclusion Criteria:  - Adult patients who aged 20-70 years with ASA-PS 1-3, BMI <30 undergoing lumbar fusion surgery under general anesthesia  Exclusion Criteria:  Tolerance or hypersensitivity to benzodiazepine or propofol Dependence or addiction to psychotropic drugs or alcohol Pregnant women subjects who lack the ability to make decisions and susceptible to voluntary participation decisions