skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: On the Effects of Pain on fNIRS Classification
We present the first study of the effects of pain on the classification of fNIRS recordings, and evaluate the performance of a model trained on the pain-free data for classifying the data with the presence of pain.  more » « less
Award ID(s):
1841087
PAR ID:
10169032
Author(s) / Creator(s):
;
Date Published:
Journal Name:
The OSA Biophotonics Congress
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. In an attempt to understand human physiological signals when an individual is subjected to pain, we set up a tonic pain experiment in a laboratory setting. The subjects’ physiological signals were recorded, timestamped, and compared to an initial 30 second baseline measurement. Subjects were also asked to verbally state their level of pain based on a visual analog scale in order to compare reported pain levels with physiological signals. The physiological signals measured were: Electroencephalography (EEG), Pupillary Unrest Under Ambient Light (PUAL), Skin Conductance (SC), Electromyography (EMG), Respiration Rate (RR), Blood Volume Pulse (BVP), Skin Temperature (ST), Blood Pressure (BP), and Facial Expression (FE). ANOVA and frequency domain analyses were conducted on the data in order to determine whether there was a significant difference between the ‘pain’ and ‘no pain’ (baseline) states of an individual. Based on our results, skin conductance, PUAL, facial expression, and EEG signals were theorized to be good signals for the classification of tonic pain, or any pain applied directly to an individual. 
    more » « less
  2. Pain is known to disrupt sleep patterns, and disturbances in sleep can further worsen pain symptoms. Sleep spindles occur during slow wave sleep and have established effects on sensory and affective processing in mammals. A number of chronic neuropsychiatric conditions, meanwhile, are known to alter sleep spindle density. The effect of persistent pain on sleep spindle waves, however, remains unknown, and studies of sleep spindles are challenging due to long period of monitoring and data analysis. Utilizing automated sleep spindle detection algorithms built on deep learning, we can monitor the effect of pain states on sleep spindle activity. In this study, we show that in a chronic pain model in rodents, there is a significant decrease in sleep spindle activity compared to controls. Meanwhile, methods to restore sleep spindles are associated with decreased pain symptoms. These results suggest that sleep spindle density correlates with chronic pain and may be both a potential biomarker for chronic pain and a target for neuromodulation therapy. 
    more » « less
  3. Background: Early-life pain is associated with adverse neurodevelopmental consequences; and current pain assessment practices are discontinuous, inconsistent, and highly dependent on nurses’ availability. Furthermore, facial expressions in commonly used pain assessment tools are not associated with brain-based evidence of pain. Purpose: To develop and validate a machine learning (ML) model to classify pain. Methods: In this retrospective validation study, using a human-centered design for Embedded Machine Learning Solutions approach and the Neonatal Facial Coding System (NFCS), 6 experienced neonatal intensive care unit (NICU) nurses labeled data from randomly assigned iCOPEvid (infant Classification Of Pain Expression video) sequences of 49 neonates undergoing heel lance. NFCS is the only observational pain assessment tool associated with brain-based evidence of pain. A standard 70% training and 30% testing split of the data was used to train and test several ML models. NICU nurses’ interrater reliability was evaluated, and NICU nurses’ area under the receiver operating characteristic curve (AUC) was compared with the ML models’ AUC. Results: Nurses weighted mean interrater reliability was 68% (63%-79%) for NFCS tasks, 77.7% (74%-83%) for pain intensity, and 48.6% (15%-59%) for frame and 78.4% (64%-100%) for video pain classification, with AUC of 0.68. The best performing ML model had 97.7% precision, 98% accuracy, 98.5% recall, and AUC of 0.98. Implications for Practice and Research: The pain classification ML model AUC far exceeded that of NICU nurses for identifying neonatal pain. These findings will inform the development of a continuous, unbiased, brain-based, nurse-in-the-loop Pain Recognition Automated Monitoring System (PRAMS) for neonates and infants. 
    more » « less
  4. Abstract Wealth‐based disparities in health care wherein the poor receive undertreatment in painful conditions are a prominent issue that requires immediate attention. Research with adults suggests that these disparities are partly rooted in stereotypes associating poor individuals with pain insensitivity. However, whether and how children consider a sufferer's wealth status in their pain perceptions remains unknown. The present work addressed this question by testing 4‐ to 9‐year‐olds from the US and China. In Study 1 (N = 108, 56 girls, 79% White), US participants saw rich and poor White children experiencing identical injuries and indicated who they thought felt more pain. Although 4‐ to 6‐year‐olds responded at chance, children aged seven and above attributed more pain to the poor than to the rich. Study 2 with a new sample of US children (N = 111, 56 girls, 69% White) extended this effect to judgments of White adults’ pain. Pain judgments also informed children's prosocial behaviors, leading them to provide medical resources to the poor. Studies 3 (N = 118, 59 girls, 100% Asian) and 4 (N = 80, 40 girls, 100% Asian) found that, when evaluating White and Asian people's suffering, Chinese children began to attribute more pain to the poor than to the rich earlier than US children. Thus, unlike US adults, US children and Chinese children recognize the poor's pain from early on. These findings add to our knowledge of group‐based beliefs about pain sensitivity and have broad implications on ways to promote equitable health care. Research HighlightsFour studies examined whether 4‐ to 9‐year‐old children's pain perceptions were influenced by sufferers’ wealth status.US children attributed more pain to White individuals of low wealth status than those of high wealth status by age seven.Chinese children demonstrated an earlier tendency to attribute more pain to the poor (versus the rich) compared to US children.Children's wealth‐based pain judgments underlied their tendency to provide healthcare resources to people of low wealth status. 
    more » « less
  5. Timely detection of horse pain is important for equine welfare. Horses express pain through their facial and body behavior, but may hide signs of pain from unfamiliar human observers. In addition, collecting visual data with detailed annotation of horse behavior and pain state is both cumbersome and not scalable. Consequently, a pragmatic equine pain classification system would use video of the unobserved horse and weak labels. This paper proposes such a method for equine pain classification by using multi-view surveillance video footage of unobserved horses with induced orthopaedic pain, with temporally sparse video level pain labels. To ensure that pain is learned from horse body language alone, we first train a self-supervised generative model to disentangle horse pose from its appearance and background before using the disentangled horse pose latent representation for pain classification. To make best use of the pain labels, we develop a novel loss that formulates pain classification as a multi-instance learning problem. Our method achieves pain classification accuracy better than human expert performance with 60% accuracy. The learned latent horse pose representation is shown to be viewpoint covariant, and disentangled from horse appearance. Qualitative analysis of pain classified segments shows correspondence between the pain symptoms identified by our model, and equine pain scales used in veterinary practice. 
    more » « less