title: Real-Time Classification of Patients with Balance Disorders vs. Normal Subjects Using a Low-Cost Small Wireless Wearable Gait Sensor.
abstract: Gait analysis using wearable wireless sensors can be an economical, convenient and effective way to provide diagnostic and clinical information for various health-related issues. In this work, our custom designed low-cost wireless gait analysis sensor that contains a basic inertial measurement unit (IMU) was used to collect the gait data for four patients diagnosed with balance disorders and additionally three normal subjects, each performing the Dynamic Gait Index (DGI) tests while wearing the custom wireless gait analysis sensor (WGAS). The small WGAS includes a tri-axial accelerometer integrated circuit (IC), two gyroscopes ICs and a Texas Instruments (TI) MSP430 microcontroller and is worn by each subject at the T4 position during the DGI tests. The raw gait data are wirelessly transmitted from the WGAS to a near-by PC for real-time gait data collection and analysis. In order to perform successful classification of patients vs. normal subjects, we used several different classification algorithms, such as the back propagation artificial neural network (BP-ANN), support vector machine (SVM),k-nearest neighbors (KNN) and binary decision trees (BDT), based on features extracted from the raw gait data of the gyroscopes and accelerometers. When the range was used as the input feature, the overall classification accuracy obtained is 100% with BP-ANN, 98% with SVM, 96% with KNN and 94% using BDT. Similar high classification accuracy results were also achieved when the standard deviation or other values were used as input features to these classifiers. These results show that gait data collected from our very low-cost wearable wireless gait sensor can effectively differentiate patients with balance disorders from normal subjects in real time using various classifiers, the success of which may eventually lead to accurate and objective diagnosis of abnormal human gaits and their underlying etiologies in the future, as more patient data are being collected.
authors.affiliation: The Department of Electrical & Computer Engineering, Texas Tech University (TTU), Lubbock, 79409 TX, USA. bhargava.nukala@ttu.edu.
authors.forename: Bhargava Teja
authors.initials: BT
authors.lastname: Nukala
authors.affiliation: The Department of Electrical & Computer Engineering, Texas Tech University (TTU), Lubbock, 79409 TX, USA. ntaro1031@gmail.com.|(On Leave) The Department Electrical & Electronic Engineering, Tokushima University, 770-8502 Tokushima, Japan. ntaro1031@gmail.com.
authors.forename: Taro
authors.initials: T
authors.lastname: Nakano
authors.affiliation: Boys Town National Research Hospital, Omaha, 68131 NE, USA. Amanda.rodriguez@boystown.org.
authors.forename: Amanda
authors.initials: A
authors.lastname: Rodriguez
authors.affiliation: The Department of Electrical & Computer Engineering, Texas Tech University (TTU), Lubbock, 79409 TX, USA. jerry.tsay@ttu.edu.
authors.forename: Jerry
authors.initials: J
authors.lastname: Tsay
authors.affiliation: The Department of Electrical & Computer Engineering, Texas Tech University (TTU), Lubbock, 79409 TX, USA. jerry@noisefigure.com.
authors.forename: Jerry
authors.initials: J
authors.lastname: Lopez
authors.affiliation: The Department of Electrical & Computer Engineering, Texas Tech University (TTU), Lubbock, 79409 TX, USA. tam.nguyen@ttuhsc.edu.|Texas Tech University Health Sciences Center (TTUHSC), Lubbock, 79439 TX, USA. tam.nguyen@ttuhsc.edu.
authors.forename: Tam Q
authors.initials: TQ
authors.lastname: Nguyen
authors.affiliation: Texas Tech University Health Sciences Center (TTUHSC), Lubbock, 79439 TX, USA. steven.zupancic@ttuhsc.edu.
authors.forename: Steven
authors.initials: S
authors.lastname: Zupancic
authors.affiliation: The Department of Electrical & Computer Engineering, Texas Tech University (TTU), Lubbock, 79409 TX, USA. donald.lie@ttu.edu.|Texas Tech University Health Sciences Center (TTUHSC), Lubbock, 79439 TX, USA. donald.lie@ttu.edu.
authors.forename: Donald Y C
authors.initials: DY
authors.lastname: Lie
mesh_terms: D000465:Algorithms; D005684:Gait; D006801:Humans; D016571:Neural Networks, Computer; D004856:Postural Balance; D012678:Sensation Disorders / Q000175:diagnosis* / Q000503:physiopathology*; D060388:Support Vector Machine; D017216:Telemedicine; D059015:Wireless Technology
keywords: artificial neural network (ANN); back propagation (BP); binary decision trees (BDT); fall detection; fall prevention; k-nearest neighbors (KNN); support vector machine (SVM); wireless gait analysis sensor (WGAS)