Inclusion Criteria:  Patients scheduled to undergo elective surgery including thoracic surgery abdominal surgery, primary hip replacement and radical mastectomy ; Age≥18 ASA Ⅰ～Ⅲ Able to wear smart band  Exclusion Criteria:  With preoperative unconsciousness Day surgery (planned LOS < 1 day) Wheelchair, walking aid or crutch were used before operation Unable to walk due to physical limitations The collection time of preoperative steps was less than 1 week The patient refused to participate