This study aims to develop a wearable electrocardiograph monitoring device and smartphone application in perioperative pain management, also to evaluate relationship between postoperative pain and heart rate variability.

This study is a prospective observational cohort study implementing wearable electrocardiogram (ECG) monitor device and smartphone application in perioperative pain management. Patients undergoing major abdominal surgical procedures will be recruited to wear a ECG monitor device from the day before surgery until 1-3days after surgery. Patients will report their condition of pain twice daily on the corresponding smartphone application based on a structured and visualized pain report module. Patients will receive a telephone follow-up 30/60/90/365 days after surgery for assessment of postoperative chronic pain. A pilot study will be conducted to evaluate acceptability, safety and feasibility of the device and application using system usability scale and comprehensive product quality assessment. Further study will be conducted to evaluate the relationship between postoperative acute and chronic pain and heart rate variability (HRV) acquired from ECG device.

Inclusion Criteria:

• patients undergoing major abdominal surgical procedures;
• 18-65 years old;
• ASA classification: I-IV
• able to read and understand how to use the App after instruction；
• written informed consent obtained.

Exclusion Criteria:

• current participation in other mobile device research or perioperative pain research;
• inability to use the device;
• inability to obtain consent.

Patients undergoing major abdominal surgical procedures in Peking Union Medical College Hospital