Abstract
Purpose
This study aimed to assess whether an artificial intelligence model based on facial expressions can accurately predict significant postoperative pain.
Methods
A total of 155 facial expressions from patients who underwent gastric cancer surgery were analyzed to extract facial action units (AUs), gaze, landmarks, and positions. These features were used to construct various machine learning (ML) models, designed to predict significant postoperative pain intensity (NRS ≥ 7) from less significant pain (NRS < 7). Significant AUs predictive of NRS ≥ 7 were determined and compared to AUs known to be associated with pain in awake patients. The area under the receiver operating characteristic curves (AUROCs) of the ML models was calculated and compared using DeLong’s test.
Results
AU17 (chin raising) and AU20 (lip stretching) were found to be associated with NRS ≥ 7 (both P ≤ 0.004). AUs known to be associated with pain in awake patients did not show an association with pain in postoperative patients. An ML model based on AU17 and AU20 demonstrated an AUROC of 0.62 for NRS ≥ 7, which was inferior to a model based on all AUs (AUROC = 0.81, P = 0.006). Among facial features, head position and facial landmarks proved to be better predictors of NRS ≥ 7 (AUROC, 0.85–0.96) than AUs. A merged ML model that utilized gaze and eye landmarks, as well as head position and facial landmarks, exhibited the best performance (AUROC, 0.90) in predicting significant postoperative pain.
Conclusion
ML models using facial expressions can accurately predict the presence of significant postoperative pain and have the potential to screen patients in need of rescue analgesia.
Trial registration number
This study was registered at ClinicalTrials.gov (NCT05477303; date: June 17, 2022).
Similar content being viewed by others
References
Apfelbaum JL, Chen C, Mehta SS, Gan TJ. Postoperative pain experience: results from a national survey suggest postoperative pain continues to be undermanaged. Anesth Analg. 2003;97:534–40. https://doi.org/10.1213/01.Ane.0000068822.10113.9e.
Gan TJ, Habib AS, Miller TE, White W, Apfelbaum JL. Incidence, patient satisfaction, and perceptions of post-surgical pain: results from a US national survey. Curr Med Res Opin. 2014;30:149–60. https://doi.org/10.1185/03007995.2013.860019.
Kehlet H, Jensen TS, Woolf CJ. Persistent postsurgical pain: risk factors and prevention. Lancet. 2006;367:1618–25. https://doi.org/10.1016/s0140-6736(06)68700-x.
Bijur PE, Latimer CT, Gallagher EJ. Validation of a verbally administered numerical rating scale of acute pain for use in the emergency department. Acad Emerg Med. 2003;10:390–2. https://doi.org/10.1111/j.1553-2712.2003.tb01355.x.
Bahreini M, Jalili M, Moradi-Lakeh M. A comparison of three self-report pain scales in adults with acute pain. J Emerg Med. 2015;48:10–8. https://doi.org/10.1016/j.jemermed.2014.07.039.
Chien CW, Bagraith KS, Khan A, Deen M, Strong J. Comparative responsiveness of verbal and numerical rating scales to measure pain intensity in patients with chronic pain. J Pain. 2013;14:1653–62. https://doi.org/10.1016/j.jpain.2013.08.006.
Gagliese L, Weizblit N, Ellis W, Chan VWS. The measurement of postoperative pain: a comparison of intensity scales in younger and older surgical patients. Pain. 2005;117:412–20. https://doi.org/10.1016/j.pain.2005.07.004.
Practice guidelines for. Acute pain management in the perioperative setting: an updated report by the American Society of Anesthesiologists Task Force on Acute Pain Management. Anesthesiology. 2004;100:1573–81. https://doi.org/10.1097/00000542-200406000-00033.
Dawes TR, Eden-Green B, Rosten C, Giles J, Governo R, Marcelline F, et al. Objectively measuring pain using facial expression: is the technology finally ready? Pain Manag. 2018;8:105–13. https://doi.org/10.2217/pmt-2017-0049.
Kunz M, Mylius V, Schepelmann K, Lautenbacher S. On the relationship between self-report and facial expression of pain. J Pain. 2004;5:368–76. https://doi.org/10.1016/j.jpain.2004.06.002.
Ekman P, Friesen WV. Measuring facial movement. Environ Psychol Nonverbal Behav. 1976;1:56–75. https://doi.org/10.1007/BF01115465.
Cohn JF, Ambadar Z, Ekman P. Observer-based measurement of facial expression with the Facial Action Coding System. 2007.
Prkachin KM. Assessing pain by facial expression: facial expression as nexus. Pain Res Manag. 2009;14:53–8. https://doi.org/10.1155/2009/542964.
Prkachin KM. Facial pain expression. Pain Manag. 2011;1:367–76. https://doi.org/10.2217/pmt.11.22.
Prkachin KM. The consistency of facial expressions of pain: a comparison across modalities. Pain. 1992;51:297–306. https://doi.org/10.1016/0304-3959(92)90213-u.
Ashraf AB, Lucey S, Cohn JF, Chen T, Ambadar Z, Prkachin KM, et al. The painful Face - Pain expression Recognition using active appearance models. Image Vis Comput. 2009;27:1788–96. https://doi.org/10.1016/j.imavis.2009.05.007.
Lucey P, Cohn J, Lucey S, Matthews I, Sridharan S, Prkachin KM. (2009) Automatically Detecting Pain Using Facial Actions. Int Conf Affect Comput Intell Interact Workshops. 2009:1–8. https://doi.org/10.1109/acii.2009.5349321.
Lucey P, Cohn J, Lucey S, Sridharan S, Prkachin KM. Automatically detecting action units from faces of pain: Comparing shape and appearance features. 2009 IEEE Computer Society Conference on Computer Vision and Pattern Recognition Workshops. 2009. p. 12 – 8.
Fontaine D, Vielzeuf V, Genestier P, Limeux P, Santucci-Sivilotto S, Mory E, et al. Artificial intelligence to evaluate postoperative pain based on facial expression recognition. Eur J Pain. 2022;26:1282–91. https://doi.org/10.1002/ejp.1948.
Chernik DA, Gillings D, Laine H, Hendler J, Silver JM, Davidson AB, et al. Validity and reliability of the Observer’s Assessment of Alertness/Sedation scale: study with intravenous midazolam. J Clin Psychopharmacol. 1990;10:244–51.
Baltrusaitis T, Zadeh A, Lim YC, Morency LP. OpenFace 2.0: Facial Behavior Analysis Toolkit. 2018 13th IEEE International Conference on Automatic Face & Gesture Recognition (FG 2018). 2018. p. 59–66.
Quality improvement guidelines for the treatment of acute pain and cancer pain. American Pain Society Quality of Care Committee. JAMA. 1995;274:1874–80. https://doi.org/10.1001/jama.1995.03530230060032.
Gordon DB, Dahl JL, Miaskowski C, McCarberg B, Todd KH, Paice JA, et al. American pain society recommendations for improving the quality of acute and cancer pain management: American Pain Society Quality of Care Task Force. Arch Intern Med. 2005;165:1574–80. https://doi.org/10.1001/archinte.165.14.1574.
Chawla NV, Bowyer KW, Hall LO, Kegelmeyer WP. SMOTE: synthetic minority over-sampling technique. J Artif Intell Res. 2002;16:321–57.
Prkachin KM, Solomon PE. The structure, reliability and validity of pain expression: evidence from patients with shoulder pain. Pain. 2008;139:267–74. https://doi.org/10.1016/j.pain.2008.04.010.
Prajapati GL, Patle A. On Performing Classification Using SVM with Radial Basis and Polynomial Kernel Functions. 2010 3rd International Conference on Emerging Trends in Engineering and Technology. 2010. p. 512-5.
Prkachin KM, Mercer SR. Pain expression in patients with shoulder pathology: validity, properties and relationship to sickness impact. Pain. 1989;39:257–65. https://doi.org/10.1016/0304-3959(89)90038-9.
LeResche L. Facial expression in pain: a study of candid photographs. J Nonverbal Behav. 1982;7:46–56. https://doi.org/10.1007/BF01001777.
Chou R, Gordon DB, de Leon-Casasola OA, Rosenberg JM, Bickler S, Brennan T, et al. Management of Postoperative Pain: a clinical practice Guideline from the American Pain Society, the American Society of Regional Anesthesia and Pain Medicine, and the American Society of Anesthesiologists’ Committee on Regional Anesthesia, Executive Committee, and Administrative Council. J Pain. 2016;17:131–57. https://doi.org/10.1016/j.jpain.2015.12.008.
Acknowledgements
None.
Funding
The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.
Author information
Authors and Affiliations
Contributions
All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Insun Park, Jae Hyon Park, and Jongjin Yoon. The first draft of the manuscript was written by Insun Park, and Jae Hyon Park, and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.
Corresponding author
Ethics declarations
Ethics approval and consent to participate
This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the institutional review board (IRB) of the Seoul National University Bundang Hospital (Chairperson Hak Chul Jang, B-2205-757-304) on 9 May 2022.
Consent to participate
Informed consent was obtained from all individual participants included in the study.
Consent to publish
The authors affirm that the participant (co-1st author: Jae Hyon Park) provided informed consent for publication of the image in Fig. 1.
Competing interests
The authors have no relevant financial or non-financial interests to disclose.
Additional information
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Park, I., Park, J.H., Yoon, J. et al. Artificial intelligence model predicting postoperative pain using facial expressions: a pilot study. J Clin Monit Comput 38, 261–270 (2024). https://doi.org/10.1007/s10877-023-01100-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10877-023-01100-7