-
[show abstract]
[hide abstract]
ABSTRACT: Functional Electrical Stimulation (FES) is a technology to generate neural activity in an artificial way to activate muscles. However, as reported by some researchers, the human responses to FES are likely to be affected by several factors, such as spasticity, muscle fatigue, nerve habituation and so forth. Consequently, the function restoration by FES is neither durable, nor stable. In order to realize long-term and stable FES assistance, this study investigated whether and why an Auxiliary Stimulation (AS) to the Gastrocnemius, with current frequency ranged from 2000 to 6000 Hz, could alleviate the symptom of spasticity and muscle fatigue caused by the stimulation to the Tibialis Anterior. We have developed a portable auxiliary stimulator, and performed experiments to verify its effectiveness. The results showed that our approach enabled comparatively stable and durable function restoration assistance. Moreover, for understanding underlying neuromuscular processes elicited by the AS and its qualitative nature, this study also measured the Hoffmann-reflex (H-reflex) in soleus muscle before and after the AS, to interpret the effect of the Auxiliary Stimulation.
Journal of Medical Systems 10/2011; 35(5):855-61. · 1.13 Impact Factor
-
J. Medical Systems. 01/2011; 35:855-861.
-
4th International Conference on Biomedical Engineering and Informatics, BMEI 2011, Shanghai, China, October 15-17, 2011; 01/2011
-
[show abstract]
[hide abstract]
ABSTRACT: As reported by some researchers, human responses to Functional Electrical Stimulation (FES) are likely to be affected by several factors, such as spasticity, muscle fatigue, nerve habituation and so forth. In our previous study, it has been shown that, an sub-threshold Auxiliary Stimulation (AS) to the Gastrocnemius, with current frequency ranged from 2000 to 6000Hz, could alleviate the symptom of spasticity and muscle fatigue caused by the stimulation to the Tibialis Anterior, enable comparatively stable and durable function restoration assistance. To understand the underlying neuromuscular processes elicited by the auxiliary electrical stimulation and its qualitative natures, we have measured the Hoffmann-reflex (H-reflex) in human soleus muscle before and after the AS in this study,, and proposed a mathematical model which takes into consideration not only the efferent but also afferent neural pathways, to interpret the effectiveness of the AS. Based on the results from the experiment it can be noted that: H(max)/M(max) became lower after AS, AS could reduce the excessive excitability of Alpha MNs. The mathematical model of pre-synaptic inhibition could help us to understand the underlying neuromuscular processes elicited by electrical stimulation and its qualitative nature, and used it to predict the states of spinal cord more easily, quickly, and reasonably in clinic experiment as a medical evaluation method for the paralyzed humans.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 01/2010; 2010:5843-6.
