Innovative single-sensor, in-shoe pressure and temperature monitoring device: A static laboratory validation study

To perform laboratory static validation of pressures from an innovative, single-sensor pressure and temperature monitoring device for the early detection of complications in the high-risk foot.

Can an innovative, newly developed, in-shoe pressure and temperature measuring device, detect and measure the in-shoe peak plantar pressures and skin temperature as accurately as the reference standard?

A pressure generating rig, the Tekscan™ Equilibration 'bladder calibrator', was used to produce a known force, against the gold standard, FScan™ in-shoe pressure mapping system by Tekscan™ and a newly developed prototype. The F-scan® system was used to record the pressure readings and establish a baseline for the readings recorded utilising the prototype. A total of 20 pressure values were recorded with 100 samples each.

Exploratory data analysis was conducted to gain insights and analyse the prototype's behaviour at different pressure points. Pre-processing and data cleaning were also performed to remove any anomalies. Support Vector Regressor with a polynomial kernel and Grid-Search algorithm was used to fit the recorded data curve. The best combination of parameters had a Mean Squared Error of 2.59 and a Root Mean Squared Error of 1.61. A simple linear equation was used to convert raw readings to pressure values.

The results of this study conclude that the pressure measurements taken with the prototype are congruent to the gold standard, F-scan® in-shoe system. This confirms that the prototype is a valid device that can be used safely as a low-cost alternative to current costly commercial in-shoe pressure mapping devices.