Real-time closed-loop control of cognitive load in neurological patients during robot-assisted gait training

Alexander Koenig*, Domen Novak, Ximena Omlin, Michael Pulfer, Eric Perreault, Lukas Zimmerli, Matjaz Mihelj, Robert Riener

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

79 Scopus citations

Abstract

Cognitively challenging training sessions during robot-assisted gait training after stroke were shown to be key requirements for the success of rehabilitation. Despite a broad variability of cognitive impairments amongst the stroke population, current rehabilitation environments do not adapt to the cognitive capabilities of the patient, as cognitive load cannot be objectively assessed in real-time. We provided healthy subjects and stroke patients with a virtual task during robot-assisted gait training, which allowed modulating cognitive load by adapting the difficulty level of the task. We quantified the cognitive load of stroke patients by using psychophysiological measurements and performance data. In open-loop experiments with healthy subjects and stroke patients, we obtained training data for a linear, adaptive classifier that estimated the current cognitive load of patients in real-time. We verified our classification results via questionnaires and obtained 88% correct classification in healthy subjects and 75% in patients. Using the pre-trained, adaptive classifier, we closed the cognitive control loop around healthy subjects and stroke patients by automatically adapting the difficulty level of the virtual task in real-time such that patients were neither cognitively overloaded nor under-challenged.

Original languageEnglish (US)
Article number5977262
Pages (from-to)453-464
Number of pages12
JournalIEEE Transactions on Neural Systems and Rehabilitation Engineering
Volume19
Issue number4
DOIs
StatePublished - Aug 2011

Funding

Manuscript received November 08, 2010; revised March 24, 2011; accepted June 10, 2011. Date of current version August 10, 2011. This work was supported by the EU Project MIMICS funded by the European Community’s Seventh Framework Program (FP7/2007-2013) under Grant 215756.

Keywords

  • Bio cooperative control
  • Lokomat
  • cognitive control
  • psychophysiology
  • stroke rehabilitation

ASJC Scopus subject areas

  • Rehabilitation
  • General Neuroscience
  • Internal Medicine
  • Biomedical Engineering

Fingerprint

Dive into the research topics of 'Real-time closed-loop control of cognitive load in neurological patients during robot-assisted gait training'. Together they form a unique fingerprint.

Cite this