University of Twente Student Theses


Minimal sensing of quality of upper-limb movements

Jafarzadeh Esfahani, Mahdad (2019) Minimal sensing of quality of upper-limb movements.

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Abstract:Physiotherapists supervise task-oriented recovery process of stroke patients during clinical assessment sessions; however, these patients should be also followed up after discharge from the clinic and during activities of daily living (ADL). Stroke survivors are faced with hardships while performing ADL due to their restricted arm functionality. Therefore, monitoring and subsequent assessment of the task performance during ADL would lead to efficient rehabilitation procedures. The aim of this study is to develop a stand-alone, minimal-sensing wearable system based on inertial measurement units (IMUs) capable of recognizing various ADL and subsequently assessing the quality of upper-limb movements. The proposed sensing system comprised three IMUs, one located at the sternum and two other sensors on the distal parts of the left and right forearms close to wrists. Human activity recognizer (HAR) of the study was developed using artificial neural network (ANN) and 10-fold cross-validation approach of HAR development showed an accuracy of 94.02 % and 98.08% for detecting 2D-planar and 3D reaching events, respectively. The quality of the detected reaching events was assessed using various validated metrics such as smoothness, workspace area, and relative displacement of hand with respect to sternum. Feasibility of smoothness analysis using the proposed system was validated by the Xsens full-body capture system, although displacement estimations were problematic. Displacement estimates using minimal sensor setup were seen to be inconsistent between different reaching-included tasks by having errors ranging from 0.1 to 7.98 cm when compared to the full-body suit outcomes. Furthermore, in this study, it is proposed that smoothness analysis solely may not be a comprehensive metric for quality of movement assessment. It was seen that there exist some quite smooth movements in which relative displacement of hand and sternum are comparatively short, which is a sign for the existence of compensatory strategies. Thus, the relative displacement of hand and sternum together with smoothness of movement complement the quality upper-limb movement assessment.
Item Type:Essay (Master)
Faculty:TNW: Science and Technology
Subject:50 technical science in general, 58 process technology
Programme:Biomedical Engineering MSc (66226)
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