Optimization techniques for underfoot pressure measurement

• Main Author: Alwan, Omar Hussein
• Format: Thesis
• Language: English
• Published: 2017
• Online Access: http://psasir.upm.edu.my/id/eprint/71141/1/FK%202017%2036%20-%20IR.pdf; http://psasir.upm.edu.my/id/eprint/71141/
• Institution: Universiti Putra Malaysia

A plantar foot pressure measurement provides important information which can be used as a helpful tool for evaluating patients with foot complaints. Foot plantar pressure systems are devices that are used to measure underfoot pressure. They can be classified into two types: platform systems and insole systems. An insole system is flexible and portable, thereby allowing a wider variety of studies to be carried out with different gait tasks, footwear designs and terrains, while a platform system is fixed and limited to the measurement of underfoot pressure in a static condition, and is usually used for the detection of ulceration. Currently, underfoot pressure ranges have not been effectively established, and there is insufficient information about the minimum and maximum values of underfoot pressure. Likewise, constraints with regard to the implementation of insole systems still persist and are represented by the need to put a spacer on the sensor during measurements, with the problem of sensor parameters changing after the calibration. Therefore, optimization of measurement techniques have been proposed for the implementation of an insole system to measure the underfoot pressure to overcome these drawbacks. This research was approved by the Human Research Ethics Committee of Universiti Putra Malaysia. The research was aimed at measuring the pressure of 15 points under the foot for 12 samples, divided into two groups (male and female). Two techniques were used to implement the insole system for the effective measurement of underfoot pressure, namely a sensor optimization of the output voltage swing, and the setting of the physical characteristics of a spacer to be placed on the sensors. In addition, a self- calibration technique was employed with the insole system to maintain the sensor measurements and to solve the problem of the changing of the sensor parameters after a period of time following the calibration. The performance of the proposed device after the application of these techniques was tested with an insole system based on the calculation of the body weight. The results showed that the proposed insole plantar pressure device was able to measure the plantar pressure ranges effectively and was able to calculate the body weight with a measurement error of up to 5.07 % of the real value of the body weight using a weight scale. This was compared to the use of a commercial device (novel EMED system) which calculated the body weight with a measurement error of up to 9.2 %, or the use of the current insole system without any optimization technique, which calculated the body weight with a measurement error of up to 9.06 % from the real value. This work will contribute towards the benefit of the social and industrial sectors in terms of measurement precision.