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Tesi etd-09112018-123142

Thesis type
Tesi di laurea magistrale
Development of a smart anklet for a soft exoskeleton
Corso di studi
relatore Prof. Cianchetti, Matteo
relatore Ing. Beccai, Lucia
tutor Ing. Totaro, Massimo
Parole chiave
  • soft exoskeleton
  • wearable system
  • strain sensor
  • human motion monitoring
  • capacitive sensor
Data inizio appello
Secretata d'ufficio
Data di rilascio
Riassunto analitico
Recently, there has been an increasing interest in the development of wearable robots defined soft exoskeletons to assist elderly as well as patients with limb pathologies, for rehabilitation and movement assistance. One of the principal requirement of the exoskeletons is to reveal the human movement in order to provide feedback about abnormal posture or walking. For this purpose, a stretchable, flexible and wearable system has been developed to measure human kinematics; in particular this is a capacitive sensor composed of conductive textiles and elastomeric layers, with a three-electrode configuration, distributed on specific garments for the knee and for the ankle. Starting from an existing prototype of a smart anklet, the aim of this thesis was to conceive and fabricate a new sensorized garment with an optimized number of sensors in order to improve the wearability, to reduce the physical and electronic encumbrance and to guarantee a good accuracy in the individuation of the gait cycle phases. The anklet was designed, developed and tested on 4 healthy subjects, walking at 3 different velocities. A motion capture system was used to measure joint ankle angles during walking. Consequently, the sensors output signals were correlated with the acquired angles with a simple reconstruction algorithm. Data were analysed and results have shown that the smart anklet is able to detect movement on both the sagittal plane and the frontal plane during walking, with a high accuracy (RMSE < 4°). The RMSE has shown to increase with the walking velocity, and in the first subject, the RMSE was higher (with a maximum of 8°). This is probably linked to the different adaptability of the anklet to the anatomy of the foot in each subject. This means that the concept of wearability has an inter-subject variability and each wearable device has to be customized on the user. Future works could focus on multi-subject tests in order to find specific parameters to standardise the smart anklet.