title: Automatic detection of freezing of gait events in patients with Parkinson's disease.
abstract: The aim of this study is to detect freezing of gait (FoG) events in patients suffering from Parkinson's disease (PD) using signals received from wearable sensors (six accelerometers and two gyroscopes) placed on the patients' body. For this purpose, an automated methodology has been developed which consists of four stages. In the first stage, missing values due to signal loss or degradation are replaced and then (second stage) low frequency components of the raw signal are removed. In the third stage, the entropy of the raw signal is calculated. Finally (fourth stage), four classification algorithms have been tested (Naïve Bayes, Random Forests, Decision Trees and Random Tree) in order to detect the FoG events. The methodology has been evaluated using several different configurations of sensors in order to conclude to the set of sensors which can produce optimal FoG episode detection. Signals recorded from five healthy subjects, five patients with PD who presented the symptom of FoG and six patients who suffered from PD but they do not present FoG events. The signals included 93 FoG events with 405.6s total duration. The results indicate that the proposed methodology is able to detect FoG events with 81.94% sensitivity, 98.74% specificity, 96.11% accuracy and 98.6% area under curve (AUC) using the signals from all sensors and the Random Forests classification algorithm.
authors.affiliation: Unit of Medical Technology and Intelligent Information Systems, Department of Materials Science and Engineering, University of Ioannina, GR 45110 Ioannina, Greece.
authors.forename: Evanthia E
authors.initials: EE
authors.lastname: Tripoliti
authors.forename: Alexandros T
authors.initials: AT
authors.lastname: Tzallas
authors.forename: Markos G
authors.initials: MG
authors.lastname: Tsipouras
authors.forename: George
authors.initials: G
authors.lastname: Rigas
authors.forename: Panagiota
authors.initials: P
authors.lastname: Bougia
authors.forename: Michael
authors.initials: M
authors.lastname: Leontiou
authors.forename: Spiros
authors.initials: S
authors.lastname: Konitsiotis
authors.forename: Maria
authors.initials: M
authors.lastname: Chondrogiorgi
authors.forename: Sofia
authors.initials: S
authors.lastname: Tsouli
authors.forename: Dimitrios I
authors.initials: DI
authors.lastname: Fotiadis
mesh_terms: D061725:Accelerometry / Q000706:statistics & numerical data; D000203:Activities of Daily Living; D000328:Adult; D000465:Algorithms; D001499:Bayes Theorem; D016022:Case-Control Studies; D003663:Decision Trees; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005260:Female; D005684:Gait / Q000502:physiology; D020233:Gait Disorders, Neurologic / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*; D012815:Signal Processing, Computer-Assisted; D012985:Software Design; D016138:Walking / Q000502:physiology