Assessment of postoperative PAIN in children WITH computer assisted facial expression analysis

It is important to assess postoperative pain in children. There are difficulties in the assessment of pain symptoms in the postoperative period. The present study was conducted to evaluate the use of computer-aided facial expression analysis to assess postoperative pain in children. The study population consisted of patients in the age group of 7–18 years who underwent surgery at Bursa Uludağ University Faculty of Medicine Health Application and Research Hospital Pediatric Surgery Clinic between November 2019 and June 2021. The sample of the study consisted of total 83 children who agreed to participate in the study and who met the sample selection criteria. Sixty-eight children who participated in the study underwent two follow-ups and 15 children underwent one follow-up. Overall, 151 pain assessments were included in the study. Data were collected by the researcher using the Wong Baker Faces (WBS) pain rating scale and Visual Analog Scale (VAS). Data were collected from the child, mother, nurse, and one external observer. Facial action units associated with pain were used for machine estimation. OpenFace was used to analyze the child's facial action units and Python was used for machine learning algorithms. Intraclass correlation coefficient, Kappa coefficient, and linear regression analysis were used for statistical analysis of the data. The pain score predicted by the machine and the pain score assessments of the child, mother, nurse, and observer were compared. The pain assessment closest to the self-reported pain score by the child was in the order of machine prediction, mother, and nurse (p<0,05). Categorical pain classification for the presence or absence of pain revealed that the assessment closest to the child's self-report was made by the mother and machine prediction (p<0,05). In conclusion, the machine learning method used for facial expression analysis assessed in this study can potentially be used as a scalable, standard, continuous, and valid pain assessment method. It can be used as an alternative pain assessment method for nurses in clinical practice.