I want to bring to your attention two papers that have recently been published which give us an insight to possible exciting new technologies. As you are all aware, diabetic foot ulcers (DFUs) are a tremendous burden to patients.
The first is an American, multicentre study by Frykberg et al (summarised alongside) examining the feasibility and efficacy of a wireless “smart mat” to predict the development of DFUs. This device is a low-profile mat with an array of 2000 temperature sensors that scans both feet for 20 seconds when stood upon. It uses a telemedicine system designed to enable remote temperature asymmetry monitoring and analysis.
This study enrolled a cohort of 132 people with diabetes and a previous DFU who were followed for 34 weeks. They were instructed in the use of the telemedicine system and a baseline scan was obtained. Throughout the study, participants stood barefoot on the mat at home once a day for 20 seconds while skin temperatures were recorded and relayed to a central server. Subjects were telephoned if they missed four consecutive days of data collection and were withdrawn if 28 days were missed. Subjects were instructed not to use the mat if they developed an ulcer, but to resume after healing had occurred.
The primary outcomes were development of a DFU and predictive accuracy of the device in identifying DFUs within temperature asymmetry thresholds. A total of 53 DFUs in 37 subjects were recorded. The smart mat identified 97% of DFUs at a thermal asymmetry of 2.22°C, but had a false positive rate of 57%. When the threshold was raised to 3.20°C, sensitivity dropped to 70%, but the false positive rate fell to 32%. The compliance rate was good, with 86% of subjects using the system 3 days a week.
The second study by Najafi et al (summarised on the facing page) is similar, but takes this a few steps further! This American study investigated the use of an optical-fibre-based smart textile made into socks — “SmartSox” — that enable the simultaneous measurement of plantar temperature, pressure and joint angles. Thirty-three subjects with diabetic peripheral neuropathy were recruited with a mean age of 58 ± 8 years and a BMI of 31.5 ± 8 kg/m2. Subjects were asked to walk at a normal speed while wearing a pair of the sensor socks. An algorithm was designed to estimate temperature, plantar pressure and toe range of motion from the optical wavelengths generated by the SmartSox. Results were validated using thermography and peak pressure as measured by computerised pressure insoles (F-Scan) as gold standards.
Laboratory testing showed excellent agreement between the SmartSox and the gold standards (r>0.98; P<0.001). During clinical testing, a good correlation was also observed for pressure profile under different anatomical regions of interest between the SmartSox and F-Scan (r=0.67; P<0.05), as well as between thermography and SmartSox (r=0.55; P<0.050). The authors concluded this technology may be of significant clinical use.
If the concepts of these two studies are combined, we may in the future see smart technology aiding our ulcer prevention programmes, with the potential to improve outcomes significantly.
To read the article summaries, please download the PDF.
