Facial Action Unit Detection on ICU Data for Pain Assessment
This addresses pain assessment challenges for ICU patients, but it is incremental as it applies existing methods to new, real-world data without major methodological innovations.
The study evaluated OpenFace and AU R-CNN for facial action unit detection on real-world ICU data to automate pain assessment, finding that performance was significantly affected by factors like assisted breathing devices and variable lighting, highlighting the need for models trained on such data.
Current day pain assessment methods rely on patient self-report or by an observer like the Intensive Care Unit (ICU) nurses. Patient self-report is subjective to the individual and suffers due to poor recall. Pain assessment by manual observation is limited by the number of administrations per day and staff workload. Previous studies showed the feasibility of automatic pain assessment by detecting Facial Action Units (AUs). Pain is observed to be associated with certain facial action units (AUs). This method of pain assessment can overcome the pitfalls of present-day pain assessment techniques. All the previous studies are limited to controlled environment data. In this study, we evaluated the performance of OpenFace an open-source facial behavior analysis tool and AU R-CNN on the real-world ICU data. Presence of assisted breathing devices, variable lighting of ICUs, patient orientation with respect to camera significantly affected the performance of the models, although these showed the state-of-the-art results in facial behavior analysis tasks. In this study, we show the need for automated pain assessment system which is trained on real-world ICU data for clinically acceptable pain assessment system.