Development of motion measurement systems for electronic above knee prosthesis

In this study, within the frame of designing microprocessor based semi-active knee joint, a motion analysis system is designed to measure the parameters of the gait of normal and amputee subjects from imaging and direct measurements. This low cost system has been equipped for two dimensional gait analysis in the sagittal plane. Gait of an intact person is analyzed by this assembled system and its reliability has been verified by comparing with the results collected under the same circumstances by known video motion analysis system reported in the literature. The system mentioned is used to develop an ambulatory motion measuring system which can monitor the environmental conditions and user intentions is designed for an electronic above knee prosthesis to be produced. Gyroscope and accelerometer among standard sensors were selected to analyze used in prosthesis systems and ambulatory motion measurement systems due to their low cost and `easy to use' structures. Gait data collection system together with the video motion analysis was tested by considering two approaches, one with single accelerometer and the other with both sensors together. The comparison indicated that the approach using gyroscope and accelerometer showed better performance than the one using only accelerometer however keeping the complexity issue as a trade off.