Data-driven phase extraction for anomaly detection of repetitive human movements

Human movements during a specific task usually consist of inconsistency and variations. They are caused by different strategies, the pace of movement, or even anthropometric structure of each subject. This dissertation aims to develop a norm modelling methodology that can model a generic repetitive...

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Main Author: Jatesiktat, Prayook
Other Authors: Ang Wei Tech
Format: Thesis-Doctor of Philosophy
Language:English
Published: Nanyang Technological University 2019
Subjects:
Online Access:https://hdl.handle.net/10356/83253
http://hdl.handle.net/10220/47998
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-832532023-03-11T17:37:38Z Data-driven phase extraction for anomaly detection of repetitive human movements Jatesiktat, Prayook Ang Wei Tech School of Mechanical and Aerospace Engineering Robotics Research Centre DRNTU::Engineering::Mechanical engineering Human movements during a specific task usually consist of inconsistency and variations. They are caused by different strategies, the pace of movement, or even anthropometric structure of each subject. This dissertation aims to develop a norm modelling methodology that can model a generic repetitive movement in a data-driven way from a collection of the movement from healthy subjects without any manual data labelling or segmentation. Then, this model can be used to assess the abnormality of the movement during rehabilitation exercises of stroke patients. To make the method invariant to the variation in phase progression, a neural network is trained to extract phases from unlabeled time-series of kinematic features. This unsupervised learning method enhanced the generalization of the modelling process to be applied to a wide range of repetitive exercises without the need for handcrafting new features. The trained model is used to segment and time-warp the exercise data into standardized periods. This standardization allows the principal component analysis reconstruction to be applied for anomaly detection. The whole modelling workflow not only works on a gold-standard marker-based motion capture system, but it is also compatible with our motion capture system which integrates a Kinect sensor with wrist-worn inertial measurement units (IMU). The compactness and affordability of the system allow this method to be used in a home-based rehabilitation scenario where space and cost are the constraints. An evaluation on four different exercises shows good potential in separating anomalous movements from normal ones with an average area under the curve (AUC) of 0.9872 and the test on actual stroke survivors is also performed. In addition, a new real-time depth-based object tracking method is invented by training a neural network to learn a continuous signed distance field of a target object. Its flexibility allows the method to be applied to various rigid and articulated objects such as a human body. Doctor of Philosophy 2019-04-08T06:26:43Z 2019-12-06T15:18:28Z 2019-04-08T06:26:43Z 2019-12-06T15:18:28Z 2019 Thesis-Doctor of Philosophy Jatesiktat, P. (2019). Data-driven phase extraction for anomaly detection of repetitive human movements. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/83253 http://hdl.handle.net/10220/47998 10.32657/10220/47998 en 218 p. application/pdf Nanyang Technological University
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic DRNTU::Engineering::Mechanical engineering
spellingShingle DRNTU::Engineering::Mechanical engineering
Jatesiktat, Prayook
Data-driven phase extraction for anomaly detection of repetitive human movements
description Human movements during a specific task usually consist of inconsistency and variations. They are caused by different strategies, the pace of movement, or even anthropometric structure of each subject. This dissertation aims to develop a norm modelling methodology that can model a generic repetitive movement in a data-driven way from a collection of the movement from healthy subjects without any manual data labelling or segmentation. Then, this model can be used to assess the abnormality of the movement during rehabilitation exercises of stroke patients. To make the method invariant to the variation in phase progression, a neural network is trained to extract phases from unlabeled time-series of kinematic features. This unsupervised learning method enhanced the generalization of the modelling process to be applied to a wide range of repetitive exercises without the need for handcrafting new features. The trained model is used to segment and time-warp the exercise data into standardized periods. This standardization allows the principal component analysis reconstruction to be applied for anomaly detection. The whole modelling workflow not only works on a gold-standard marker-based motion capture system, but it is also compatible with our motion capture system which integrates a Kinect sensor with wrist-worn inertial measurement units (IMU). The compactness and affordability of the system allow this method to be used in a home-based rehabilitation scenario where space and cost are the constraints. An evaluation on four different exercises shows good potential in separating anomalous movements from normal ones with an average area under the curve (AUC) of 0.9872 and the test on actual stroke survivors is also performed. In addition, a new real-time depth-based object tracking method is invented by training a neural network to learn a continuous signed distance field of a target object. Its flexibility allows the method to be applied to various rigid and articulated objects such as a human body.
author2 Ang Wei Tech
author_facet Ang Wei Tech
Jatesiktat, Prayook
format Thesis-Doctor of Philosophy
author Jatesiktat, Prayook
author_sort Jatesiktat, Prayook
title Data-driven phase extraction for anomaly detection of repetitive human movements
title_short Data-driven phase extraction for anomaly detection of repetitive human movements
title_full Data-driven phase extraction for anomaly detection of repetitive human movements
title_fullStr Data-driven phase extraction for anomaly detection of repetitive human movements
title_full_unstemmed Data-driven phase extraction for anomaly detection of repetitive human movements
title_sort data-driven phase extraction for anomaly detection of repetitive human movements
publisher Nanyang Technological University
publishDate 2019
url https://hdl.handle.net/10356/83253
http://hdl.handle.net/10220/47998
_version_ 1761781881332826112