Development of EMFI-sensor based pressure sensitive insole for gait analysis

The pressure distribution of the sole includes important information of gait during walking or running. For example, by monitoring the details of pressure distributions in the sole in normal walking many malpositions of the foot can be easily detected. In this study a simple and versatile EMFI sensor based real-time pressure mapping system was developed for gait analysis purposes. The system consists of a thin and flexible insole, including 16 tiny EMFI sensor elements, connected via a customized analog amplifier and digital data acquisition card to a PC computer. The PC-software of the measurement system shows the pressure in each small sensor element of the sole in real time, and records the data to a file. The accuracy and reliability of the system was preliminarily evaluated by experimental measurements. The results showed out that the system has capability to measure the pressure distributions of the foot sole reliably. The correlation coefficient between the applied pressure and the sensor output was 0,99. The next phase of the research project is to evaluate applicability of the system for evaluation of gait with large number of test subjects.