# Non-invasive Resonance Raman Spectroscopy provides an early estimation of depth in a pig model of multi-depth burns

## TL;DR

A new non-invasive method using Resonance Raman Spectroscopy can accurately estimate burn depth early after injury in a pig model.

## Contribution

A novel Hemoglobin Index based on Resonance Raman Spectroscopy is introduced for early burn depth assessment.

## Key findings

- The Hemoglobin Index achieved 85% AUC accuracy in classifying partial-thickness burn depths on day 3 post-burn.
- The method showed nearly perfect classification for other burn categories in the multi-depth model.
- Raman-associated fluorescence could track fluorophore deposition for healing management in later phases.

## Abstract

Accurate burn depth diagnosis in the early post-burn phase is critical for treatment; however, current assessment methods are subjective, resulting in reduced diagnostic accuracy. Using a compact and portable benchtop setup, we propose a Resonance Raman Spectroscopy protocol to assess burn depth in this phase. By developing a Hemoglobin Index for wounds, we measure hemoglobin in the wound as a marker for wound perfusion, which is altered in burn injuries due to vascular damage. We tested the Hemoglobin Index for wound categorization in a clinically relevant multi-depth burns model in Yucatan pigs. We found a high accuracy of diagnosis on post-burn day 3, an 85% AUC in a binary classifier model for superficial partial-thickness and deep-partial thickness burns, with nearly perfect classification in other categories. Simultaneously, we discuss the potential use of Raman-associated fluorescence in measuring fluorophore deposition in later phases for healing management. Thus, non-invasive measurements with our device may have a high potential for clinical translation.