Is pain a physiological reality or perceptual phenomenon? Insights from SCG and ECG signal analysis

Abstract

Pain is a multifaceted experience that encompasses physiological, emotional, and cognitive components. Its subjective nature presents significant challenges for clinicians, making it difficult to assess and manage effectively. This study investigates the physiological and perceptual dimensions of pain by analyzing seismocardiogram (SCG) and electrocardiogram (ECG) signals obtained using a custom wearable patch. Data were collected from 16 participants under controlled experimental pain induction protocol. Significant changes were observed in SCG features pre- and post-pain stimulation, with mean absolute percentage changes (MAPE) of 93.7% in peak-to-peak amplitude, 72.8% in energy, and 71.1% in standard deviation. Additionally, heart rate (HR) decreased in 75% of participants following pain induction, aligning with their subjective pain scores. Similarly, galvanic skin response characteristics demonstrated moderate-to-strong correlations with SCG features. These findings underscore the potential of SCG and ECG signal analysis as objective tools for quantifying physiological responses to pain, bridging the gap between subjective and physiological assessments.