Clinical Research Directory

Inclusion Criteria: 1. Patients undergoing general anesthesia surgeries for more than 60 minutes with IBP monitoring 2. Patients aging between 4 to 80 years old (including at least 5 pediatric subjects between 4 to 12 years old, and as for subjects over 12 years old, up to 60% of subjects between 12 to 50 years old, at least 15% of subjects between 50 to 60 years old, at least 15% of subjects between 60 to 70 years old, and at least 10% of subjects over 70 years old) 3. At least 30% of subjects is male and 30% is female 4. Volunteer to participate the study and sign the informed consent form willingly Exclusion Criteria: 1. Patients with severe heart diseases which affect the stability of haemodynamics 2. Patients applied with the heart-lung machine, defibrillator or cardiopulmonary bypass 3. Patients with coagulation disorders, vasculopathy or vascular prostheses 4. Patients with cutaneous diseases, infections or trauma of the measured part of the body leading to failure of data acquisition 5. Patients with mental diseases, epilepsy or other diseases leading to involuntrary movements of the body 6. Patients with BMI no more than 17 or no less than 30 kg/m\^2 7. Patients who are pregnant or at the unstable stage of diseases or with severe shock 8. Patients with infections or trauma at the position of artery cannulation, whose pulse is untouchable or who get positive in the Allen's test 9. Patients with diseases that the investigators think unsuitable for participating the study