Assessment of Gait Spatio-temporal Parameters in Neurological Disorders Using Wearable Inertial Sensors

A mia madre e mio padre, A mia sorella " Tell me and I forget, teach me and I may remember, involve me and I learn ". Summary Movement analysis carried out in laboratory settings is a powerful, but costly solution since it requires dedicated instrumentation, space and personnel. Moreover, it cannot be used to observe the variability in performing everyday life movements. Recently, new technologies such as the 'inertial sensors' are becoming widely accepted as tools for the assessment of human motion in clinical and research settings. Inertial sensors are relatively small and inexpensive, they require low power to operate and can therefore be wearable and used outside the laboratory. The magnetic and inertial measurement units (MIMU) which integrate multiple sensors (triaxial accelerometer, triaxial gyroscope and triaxial magnetometer) are the most promising sensing units for human movement analysis carried out both inside and outside a laboratory setting. They are relatively easy-to-use and potentially suitable for estimating gait kinematic features, including spatio-temporal parameters. The objective of the research conducted and reported in this PhD thesis regards the development and testing in clinical contexts of robust MIMU based methods for assessing gait spatio-temporal parameters applicable across a number of different pathological gait patterns. First, considering the need of a solution the least obtrusive as possible, the validity of the single unit based approach was explored. A comparative evaluation of the performance of various methods reported in the literature for estimating gait temporal parameters using a single MIMU unit attached to the trunk first in normal gait and then in different pathological gait conditions was performed. The analysis was conducted in terms of accuracy, sensitivity and robustness of the tested methods with respect to a gold standard. A comparison between the results obtained for different methods and the different subjects groups was also carried out. It was shown that the use of a single MIMU is prone to different amounts of errors when applied to pathologic gait patterns. ii The second part of the research headed then towards the development of new methods for estimating gait spatio-temporal parameters using shank worn MIMUs on different pathological subjects groups. In addition to the conventional gait parameters, new methods for estimating the changes of the direction of progression were explored. Finally, a new hardware solution and relevant methodology for estimating inter-feet distance during walking was proposed. Results of the technical validation of the proposed methods …