title: A wearable system to assist walking of Parkinson s disease patients.
abstract: BACKGROUND
  About 50% of the patients with advanced Parkinson's disease (PD) suffer from freezing of gait (FOG), which is a sudden and transient inability to walk. It often causes falls, interferes with daily activities and significantly impairs quality of life. Because gait deficits in PD patients are often resistant to pharmacologic treatment, effective non-pharmacologic treatments are of special interest.
  
  
  OBJECTIVE
  The goal of our study is to evaluate the concept of a wearable device that can obtain real-time gait data, processes them and provides assistance based on pre-determined specifications.
  
  
  METHODS
  We developed a real-time wearable FOG detection system that automatically provides a cueing sound when FOG is detected and which stays until the subject resumes walking. We evaluated our wearable assistive technology in a study with 10 PD patients. Over eight hours of data was recorded and a questionnaire was filled out by each patient.
  
  
  RESULTS
  Two hundred and thirty-seven FOG events have been identified by professional physiotherapists in a post-hoc video analysis. The device detected the FOG events online with a sensitivity of 73.1% and a specificity of 81.6% on a 0.5 sec frame-based evaluation.
  
  
  CONCLUSIONS
  With this study we show that online assistive feedback for PD patients is possible. We present and discuss the patients' and physiotherapists' perspectives on wearability and performance of the wearable assistant as well as their gait performance when using the assistant and point out the next research steps. Our results demonstrate the benefit of such a context-aware system and motivate further studies.
authors.affiliation: Wearable Computing Lab, Swiss Federal Institute of Technology, ETH Zürich, Zurich, Switzerland. baechlin@ife.ee.ethz.ch
authors.forename: M
authors.initials: M
authors.lastname: Bächlin
authors.forename: M
authors.initials: M
authors.lastname: Plotnik
authors.forename: D
authors.initials: D
authors.lastname: Roggen
authors.forename: N
authors.initials: N
authors.lastname: Giladi
authors.forename: J M
authors.initials: JM
authors.lastname: Hausdorff
authors.forename: G
authors.initials: G
authors.lastname: Tröster
mesh_terms: D000368:Aged; D000553:Ambulatory Care; D003199:Computer Systems; D003463:Cues; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D010300:Parkinson Disease / Q000534:rehabilitation*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013813:Therapy, Computer-Assisted / Q000295:instrumentation*; D016138:Walking