Date of Award

Summer 8-20-2021

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science (MS)


Mechanical Engineering


Babak Hejrati

Second Committee Member

Mohsen Shahinpoor

Third Committee Member

Vincent Caccese


Until recently, study and correction of motor or gait functions required costly sensors and measurement setups (e.g., optical motion capture systems) which were only available in laboratories or clinical environments. However, due to (1) the growing availability and affordability of inertial measurement units (IMUs) with high accuracy, and (2) progress in wireless, high bandwidth, and energy-efficient networking technologies such as Bluetooth Low Energy (BLE), it is now possible to measure and provide feedback in real-time for biomechanical parameters outside of those specialized settings. To enable gait training without an expert who can provide verbal feedback, augmented feedback, which is divided into three categories of visual, auditory, and haptic is necessary. Vibrotactile haptic feedback is of particular interest because it is both affordable and does not interfere with the situational awareness of the user. Among the systems proposed in the literature, there has been an absence of a system that is user-friendly, modular (i.e., it has individual, configurable sensing and feedback components), and completely wearable (i.e., all the components can be worn and carried by the user). In this work, we aim to address that gap by developing a novel wearable and modular smartphone-based system that provides vibrotactile feedback for gait training. The system's modularity and its smartphone-based controller and user interface can enhance its usability and promote regular gait training of users, particularly older adults, during their daily living. Given the prevalence of stride length and speed decline in older adults, we developed a biomechanical data-driven approach to enable improving those outcomes via modifying their underlying surrogates. A subject study was performed by recruiting 12 young participants to assess the efficacy of the haptic system and our approach based on the notion of biomechanical surrogates. We found that the participants could significantly increase their thigh and shank extensions (i.e., the biomechanical surrogates) via the feedback provided by our system, and those increases led to higher values of stride length and walking speed. Our results provide a clear proof-of-concept for the developed biomechanics-driven haptic system for gait training of older adults to potentially improve their mobility and living independence.

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