Area of the Diabetic Ulcers Estimated Applying a Foot Scanner-Based Home Telecare System and Three Reference Methods

Background: Diabetic foot ulcer area is a basic parameter used for monitoring the wound healing and effectiveness of the treatment applied. TeleDiaFoS (developed earlier in collaboration with the Department and Clinic of Gastroenterology and Metabolic Diseases, Medical University of Warsaw, Warsaw, Poland) is one of just a few systems available that make possible monitoring of the wound size remotely based on the foot scans transmitted to the physician from a patient's home. The aim of this study was to compare the diabetic foot ulcer areas measured using TeleDiaFoS with the results obtained using three reference methods. Methods: The reference measurements were conducted using the elliptical method with a ruler, the wound tracing method and planimetrics with the Visitrak (Smith & Nephew, London, UK) system, and the pattern-coded structured light method with the Silhouette (ARANZ Medical, Christchurch, New Zealand) system. Regression and Bland-Altman analyses were performed. The study group consisted of 23 diabetes patients with plantar foot ulcers. Results: Thirty-three wounds were successfully examined. The measurement method influenced the measured area significantly (P = 0.00005). The correlation coefficients between TeleDiaFoS and the ruler, Visitrak, and Silhouette methods were 0.949, 0.985, and 0.987, and the limits of agreement equaled -1.3 +/- 5.5 cm(2), -0.4 +/- 2.2 cm(2), and -0.6 +/- 2.1 cm(2), respectively. The strong linear relationships obtained can be used to convert the wound area measured with TeleDiaFoS to the corresponding value of each of the reference methods. Conclusions: The results indicate that the wound area of plantar ulcers in diabetes might be monitored effectively using the TeleDiaFoS system based on the foot scans that the patient can produce at home with no assistance of other persons.