Measuring Coupling of Breathing and Gait Rhythms Using Cross Sample Entropy
Advisor Information
Jennifer Yentes
Location
Dr. C.C. and Mabel L. Criss Library
Presentation Type
Poster
Start Date
4-3-2016 2:30 PM
End Date
4-3-2016 4:00 PM
Abstract
It has long been suggested that various biological rhythms exhibit some degree of synchrony, and that stepping frequency is often linked to breathing frequency. Coupling of breathing and stepping rhythms is considered present when the interval between walking and breath events is constant for a series of breaths. Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation, altering breathing patterns and timing, which may in turn affect walking patterns due to coupling between breathing and walking. Many tools are available to assess coupling of different signals, however the nonlinear characteristics of walking and breathing patterns suggest that a nonlinear measure would be preferable. Cross sample entropy (xSE) was developed to quantify the probability that the patterns present in one signal will also be found in the other signal. The purpose of this study was to assess the coupling of breathing and walking patterns of persons, with and without COPD, using xSE. It was hypothesized that persons with COPD would exhibit lower xSE, indicating more closely coupled breathing and walking rhythms. Six patients with COPD and 12 healthy older controls walked on a treadmill for 3 minutes, at 5 speeds, while breathing and walking data were recorded. No significant differences in xSE were found between the groups except at the lowest speed, 20% lower than their self-selected pace (p = 0.029). When walking slowly, xSE for patients with COPD was less than controls, indicating that at these speeds breathing and walking patterns are most similar.
Measuring Coupling of Breathing and Gait Rhythms Using Cross Sample Entropy
Dr. C.C. and Mabel L. Criss Library
It has long been suggested that various biological rhythms exhibit some degree of synchrony, and that stepping frequency is often linked to breathing frequency. Coupling of breathing and stepping rhythms is considered present when the interval between walking and breath events is constant for a series of breaths. Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation, altering breathing patterns and timing, which may in turn affect walking patterns due to coupling between breathing and walking. Many tools are available to assess coupling of different signals, however the nonlinear characteristics of walking and breathing patterns suggest that a nonlinear measure would be preferable. Cross sample entropy (xSE) was developed to quantify the probability that the patterns present in one signal will also be found in the other signal. The purpose of this study was to assess the coupling of breathing and walking patterns of persons, with and without COPD, using xSE. It was hypothesized that persons with COPD would exhibit lower xSE, indicating more closely coupled breathing and walking rhythms. Six patients with COPD and 12 healthy older controls walked on a treadmill for 3 minutes, at 5 speeds, while breathing and walking data were recorded. No significant differences in xSE were found between the groups except at the lowest speed, 20% lower than their self-selected pace (p = 0.029). When walking slowly, xSE for patients with COPD was less than controls, indicating that at these speeds breathing and walking patterns are most similar.