Doctors and clinicians rely on accurate underfoot pressure data to perform diagnosis of foot diseases. In sole pressure measurement systems are designed to provide such data but its implementation suffers from certain constraints such as the need for a spacer to be placed on the sensor when taking measurements and the need for multiple calibrations due to the fact that the sensor parameters tend to change without it. In this work, we proposed an optimization technique to address these limitations. The results obtained from testing indicate that the proposed device performed measurement of plantar pressure effectively. Also, the calculation of body weight using the proposed optimization technique is improved from 5.07% to 9.06%. For validation, the results are compared with the measurements from a commercial plantar pressure device (EMED system) as benchmark.
INTRODUCTIONPlantar pressure measurement systems are often used to obtain useful data regarding the structure of the underfoot base and the distribution of pressure it exerts to the surface plane. These systems allow for the diagnosis and treatement of various problems related to posture and gait but there are inherent limitations within these systems that need to be addressed such as the lack of precision in body weight calculation, self-calibration improvements and suitability of the physical characteristics of the materials used. The work in [1, 2] studies the effects of obesity or increasing body weight and the resulting disparities in the plantar pressure distribution patterns. Another study found that increase in the human body weight was a significant factor that contributed to the plantar pressure distribution pattern [3,4]. This leads to recommendation from researchers that the diagnosis and treatment of foot problems in obese patients should consider the effects of increased body mass on their plantar loading [5,6]. The study in [7,8] then found that the relationship between mean/peak plantar pressure and increasing body mass was dependent on the affected plantar area.These prior works show that current insole systems do not consider pressure range in the measurements of plantar pressure. Thus, there is a need for a method to obtain points that can be used to produce a suitable pressure range in the plantar measurement system, specifically the maximum and minimum pressure values during walking and standing, as related to the body mass. The findings of accurate and reliable underfoot pressure ranges based on incremental body weight is needed as a benchmark or