Inexpensive color evaluation of dye-based pressure-sensitive films for plantar studies

Dye-based pressure-sensitive films are advantageous in plantar pressure studies due to their ease of use, cost-effectiveness, and ability to produce measurements within the shoe. To circumvent the use of proprietary equipment and software to relate the dye-stained film to load, an alternative approach of using a conventional flatbed scanner and generic image processing software is attempted here instead. The technique revealed high linear increasing and decreasing trends for the respective red and blue normalized intensities (R(2) > 0.95) and low standard deviation in all readings (<0.06) overall. By subtracting the blue from the red normalized intensity, it was discovered that the measurement sensitivity could be doubled. The results here confirm the viability of using a conventional flatbed scanner and generic image processing software to relate the dye-stained pressure films to load. The adoption of this approach promises substantial cost savings.