The Accuracy of Foot Temperature Measurement by Thermal Imaging and Infrared Thermometers at Varying Distances: A Quantitative Study

Abstract

Background: Thermal imaging is a new technique used in podiatry to detect foot conditions such as inflammation, vascular disorders, and infections. Accurate foot temperature measurements are essential for early detection and management of diabetic foot ulcerations. However, there is a lack of existing research on the effect of distance variation on the accuracy of the measurements. To address this gap, this study reports whether thermal imaging techniques offer similar accuracy to traditional methods when measuring foot temperature at varying distances. Methods: A quantitative study uses a repeated measures design to investigate the accuracy of foot temperature measurement using a Hik Thermal Camera (HTC) and a Non-Contact infrared thermometer (NCIT) at varying distances. The experiment involved measuring known water bath temperature and foot temperature. After 15 minutes of barefoot rest, data were collected from Twelve participants using both devices. One-way ANOVA and paired T-test were conducted to examine if distance variation impacted the accuracy of the measurements. Bland-Altman plots were performed to compare the two devices. Results: The analysis showed no significant differences in foot temperature across three locations using the NCIT where the p-value =0.449 and the HTC p-value= 0.343. A paired t-test within the control group indicated that the most accurate water temperature measurements were obtained at 2.5 cm for NCIT (p-value=0.069). In addition, there were no significant differences among data obtained using HTC (p-value higher than 0.05). The Bland-Altman findings revealed strong agreement between the devices. Conclusions: The study's result indicates no significant differences in foot temperature measurements obtained using both devices across different distances. Hik Thermal Camera (HTC) measurements showed a good agreement with data obtained from a non-contact infrared thermometer (NCIT). These findings suggest that podiatrists can use either device for accurate foot temperature measurements. Keywords: Thermal imaging, infrared thermometer, podiatry, diabetic foot ulcer, foot temperature, prevention