The use of smartphone thermography to evaluate wound healing in second-degree burns

Abstract

Background: Burn injuries can significantly affect a person's ability to function and reduce their quality of life. This study used thermal imaging to investigate the relationship between blood flow changes and healing in second-degree burns. The researchers hypothesized that improved blood flow to the burn site, as indicated by infrared thermography assessments, may be associated with better wound healing outcomes in patients with second-degree burns.

Patients and methods: This prospective, non-randomized study included 47 adults with second-degree burns who underwent a structured program of range of motion (ROM) exercises during the healing process. Wound healing progression was assessed by infrared thermography (FLIR imaging) to measure temperature differences (ΔT) between burn wounds (T2) and normal skin (T1) as an indirect marker of perfusion; the modified Abbreviated Burn Severity Index (mABSI) to classify burn severity levels; and the Bates-Jensen Wound Assessment Tool (BWAT). Measurements were taken at baseline, week one, week two, and week three following the initiation of ROM exercises.

Results: The ABSI levels showed that 46.8 % of patients had moderate severity burns, 38.3 % had very low severity, and 14.9 % had moderately severe burns. BWAT scores showed a decreasing trend over a three-week period. They began at 28.9 ± 4.6 SD, rose slightly to 30.1 ± 4.7 SD after one week indicating inflammation and wound changes, and then dropped to 19.2 ± 6.5 SD and 17.1 ± 4.3 SD in the second and third weeks respectively showing substantial healing. FLIR thermal imaging was also used to monitor the healing process by measuring the temperature difference (ΔT) between the burn wound (T2) and normal skin (T1). Larger ΔT values suggest better blood flow (perfusion) and potentially improved healing. The median ΔT values decreased over the three weeks, starting at 0.60 (IQR 1.65) and falling to 0.01 (IQR 0.20) by week three. These changes in ΔT over time were statistically significant (p < 0.001, Kruskal-Wallis test).

Conclusions: This study successfully used FLIR thermal imaging in patients undergoing a rehabilitation program focused on ROM exercises, showing a positive link with healing progress. The findings highlight the potential of FLIR thermal imaging to optimize burn management and improve patient outcomes. Further research is needed to validate these findings and develop standardized protocols for both ROM exercises and thermal imaging to enhance burn care.

Keywords: Burn; FLIR thermal imaging; Range of Motion exercise; Wound healing assessment.