Clinical Research Directory

Inclusion Criteria: * Age 65-80 years old * written informed consent of patient or family member * painless stomach + colonoscopy * ASA grade I-II Exclusion Criteria: * Patients with clotting disorders or a tendency to oropharyngeal bleeding, mucosal damage or space occupation, difficulty in placing oropharyngeal airway, etc., who could not perform oropharyngeal airway ventilation; * Upper respiratory tract infections such as mouth, nose or throat; * Fever (core body temperature ≥37.5℃); * a confirmed diagnosis of pregnancy or breastfeeding; * Allergic to sedatives such as propofol or equipment such as tape; * Emergency surgery; * Multiple trauma; * SpO2 \< 95% before operation; * A history of drug and/or alcohol abuse within 2 years prior to the start of the screening period;(Drinking more than three times standard alcoholic beverages per day, equivalent to about 10g of alcohol or equivalent to 50g of Chinese liquor); * Patients with previous psychiatric and neurological diseases, such as depression, severe central nervous depression, Parkinson's disease, basal ganglia disease, schizophrenia, epilepsy, Alzheimer's disease, myasthenia gravis; * Currently participating in other clinical trials; * Patients who are deemed unfit by the investigator to participate in the trial; * Patients with a history of smoking should not participate in this study.