Inclusion Criteria:  Signed informed consent Age >18 years ASA Physical Status > 2 Noncardiac surgery with expected surgery duration > 2 hours (example include: orthopedic, spine, urology, and general surgery) Planned blood pressure monitoring with an arterial line catheter; General anesthesia;  Exclusion Criteria:  Participating in another interventional Trial; Contraindication to arterial blood pressure monitoring; Subjects with a physical site area too limited for proper Sensor placement Serum creatine > 175 μmol/L (>2.0 mg/dL) or CKD stage > 3A Scheduled for intracranial surgery with permissive hypotension; Patient who is confirmed to be pregnant and/or nursing mothers; Patients with an intra-aortic balloon pump (IABP) or ventricular assist device(s); Have a condition that precludes routine or tight blood pressure management such as surgeon request for relative hypotension; Emergency surgery; Require beach-chair positioning; Scheduled for cardiac surgeries Have previously participated in the SMART-BP trial.