Quantitative Consciousness Index Monitoring (qNOX) of Sedation During Endoscopy

Inclusion Criteria 1. Age between 18 and 60 years old; 2. ASA-PS (American Society of Anesthesiologists Physical Status) classification of I to II; 3. Body Mass Index (BMI): 18 to 28 kg/m²; 4. Patients undergoing diagnostic and therapeutic procedures under sedation for lower gastrointestinal endoscopy; 5. Clear understanding and voluntary participation in this study, with informed consent signed. Exclusion Criteria 1. Patients requiring complex endoscopic techniques for diagnosis and treatment; 2. Patients who have participated in other clinical trials in the past three months; 3. Pregnant and lactating patients; 4. Patients with allergies to sedatives/anesthetics and other severe anesthesia risks; 5. Patients with preoperative chronic pain or a history of substance abuse; 6. Patients with severe neurological diseases such as stroke, hemiplegia, convulsions, epilepsy, etc.; 7. Patients with known difficult airways such as limited mouth opening, restricted neck and jaw movement, rheumatoid spondylitis, temporomandibular joint arthritis, etc.; 8. Patients with potentially life-threatening circulatory and respiratory diseases that are not adequately controlled, such as uncontrolled severe hypertension, severe arrhythmias, unstable angina pectoris, acute respiratory infections, asthma exacerbations, etc.; 9. Patients with liver dysfunction (Child-Pugh Class C or higher), acute upper gastrointestinal bleeding with shock, severe anemia, gastrointestinal obstruction with gastric retention.