Physiological framework for non-invasive detection and objective nociception activity in communicative patients: a...

Area of Science:

• Biomedical Engineering
• Neuroscience
• Pain Management

Background:

• Assessing pain objectively remains a clinical challenge, as current subjective tools like the Numeric Rating Scale (NRS) have limitations.
• Non-communicative patients pose particular difficulties for accurate pain assessment.

Purpose of the Study:

• To introduce and validate a novel, physiologically grounded, objective index for pain assessment derived from nociceptive dynamics.
• To evaluate the Anspec-Pro device for non-invasive, real-time measurement of nociceptive activity.

Main Methods:

• Developed a fractional-order impedance model to derive the delta T (ΔT) index from skin bioimpedance, representing nociceptive transduction (TD) and transmission (TS).
• Utilized the Anspec-Pro device for non-invasive, real-time bioimpedance recordings.
• Applied data augmentation techniques, including autoregressive modeling and transfer-function mapping, to a limited dataset of postoperative patients.

Main Results:

• The ΔT index demonstrated a strong correlation (up to 0.86) with subjective NRS pain scores, often preceding them.
• A refined index, ΔT dynamic (ΔT_dyn), improved temporal alignment with reported pain.
• Analyses of augmented data revealed significant lead-lag patterns and Granger causality between ΔT, ΔT_dyn, and NRS.

Conclusions:

• The ΔT index shows potential as an objective, non-invasive biomarker for tracking nociceptive activity.
• ΔT may serve as an anticipatory marker of pain and a real-time indicator aligned with subjective reporting.
• The Anspec-Pro device shows promise for objective nociceptive tracking in clinical settings.