Computing in Cardiology

Computing in Cardiology September, 2011

Heart rate asymmetry and emotional response to robot-assist task challenges in post-stroke patients

Herbert F. Jelinek1,
Katherine G. August2,
Md. Hasan Imam3,
Ahsan H. Khandoker3,4,
Alexander Koenig2,5,
Robert Riener2,5
1Charles Sturt University, Albury, Australia; 2University of Zurich, Zurich, Switzerland; 3University
of Melbourne, Melbourne, Australia; 4 Khalifa University, Abu Dhabi, UAE 5ETH, Zurich,
Switzerland


Abstract
The level of motivation or stress influences learning
the use of a robot-assist device for walking. Heart rate
asymmetry (HRA) indicates the level of parasympathetic
(HRA<0.5) and sympathetic (HRA>0.5) involvement in heart rate regulation. Three patients and seven controls
were presented increasing levels of task difficulty. During
training patients showed an increase in stress as indicated by the HRA index (0.524±0.02) in contrast to control participants (0.485±0.03). As the task complexity increased, the HRA in the patient group was atypical and
falling below 0.5, compared to control (HRA>0.5). The
latter result reflects an increased cognitive involvement
and a higher sympathetic predominance in accordance
with an increased task difficulty. Thus stroke affected the
response to the task challenges in that the patient response to increasing task challenge leads to an inversion of HRA associated with a decreased mental engagement and higher risk of sudden cardiac death.