Fiber Bragg Gratings based smart insole to measure plantar pressure and temperature

Abstract

Various foot complications can be easily avoided by continuously monitoring plantar (foot sole) pressure and temperature at home. Systems which can simultaneously measure plantar pressure and temperature in real time are still scarce. In this work, the design, characterization, and implementation of a Fiber Bragg Gratings (FBG) based smart insole capable of simultaneously measuring plantar pressure and temperature has been reported. The instrumented insole was tested and verified during static and gait exercises. The paper also provides a comparison of the developed optoelectronic-based solution with a commercially available and widely used plantar pressure measurement and analysis system, and a lab-made electronic sensor-based solution for simultaneously recording plantar pressure and temperature. It was shown that even though the commercial plantar pressure acquisition system is very robust and highly precise due to many sensing units on the insole, the developed insole with a much smaller number of sensors can simultaneously acquire both plantar temperature and pressure with reasonable precision while displaying both foot pressure and temperature maps, and gait cycle plots in real-time with a development cost more than eight times lower than the manufacturing cost of the commercial solution. Our proposed optoelectronic-based solution is lightweight, uncomplicated but robust, and electronically safer than the commercial system. While the proposed system is far from its optimized form, we expect that our developed prototype will instigate other researchers in this domain to further explore optoelectronic-based solutions in real-time plantar pressure and temperature monitoring.