中風是使開發中國家失去勞動力的原因之一。中風病人的腦神經網路會受到損傷，此損傷會造成肢體的運動能力喪失，進而造成日常生活的不便與降低生活品質。而在眾多的復健方式中電刺激踩車運動已被證實能藉由電刺激的輔助產生對稱且類似步態的運動來改善不完全脊椎損傷、中風等病患的肌肉無力及肢體運動能力。在電刺激輔助踩車時的肌肉收縮是由自主收縮與外部電刺激兩個不同的來源所產生，如此的肌肉活化即可視為混合式肌肉活化。雖然藉由運動復健可以使得肢體動作能力的恢復，但其效果與腦部的可塑性與復原程度的關係是尚未被了解的。此外類似踩車這樣的動態運動下的混合式肌肉活化也較少被研究。因此，本研究的目的是使用近紅外光譜儀(NIRS)來評估在電刺激踩車時的動作皮質活化狀況。並以軟體及硬體方式萃取電刺激踩車時的自主肌電圖與電刺激誘發的肌電圖訊號來協助評估混合式肌肉活化時的踩車表現。NIRS 的光學量測技術可藉由光子數量的變化來量測到電刺激輔助踩車或沒有電刺激輔助踩車時的的含氧血紅素(HbO)與缺氧血紅素(HbR)的變化。而本研究藉由健康受試者的試驗了解在健康狀況下的踩車表現與腦皮質活化反應。我們的結果顯示，自主肌電訊號的波封面積值會在有電刺激輔助踩車時的情況變小，這樣的一個變化提供了肌肉確實處於混合式肌肉活化的狀況下的一個證據。而在大腦的運動輔助區(supplementary motor area)與主要運動皮質區(primary motor cortex)的反應會在混合式肌肉活化的情況下有所上升。這有可能是因為大腦在混合式肌肉活化的情況下需要藉由這兩個腦區來處裡電刺激的干擾與影響，以維持踩車時的對稱性與平順度。在未來的研究中，運用肌電訊號的運動學評估法與藉由NIRS的腦皮質反應評估會用在單側中風的病患上，以提供以腦部為主的混合式肌肉活化的踩車復健計畫。

Stroke is one of the leading causes of disability in the United States and other developed countries. Those survived from stroke or cerebrovascular accident (CVA) may be left with physical impairments deeply affecting the activities of daily living and quality of life. Among various rehabilitation protocols, electrical stimulation (ES)-assisted cycling has been shown to be an effective measure for pre-ambulation training because cycling exercise is a symmetrical and gait-like exercise. For the limb with residual function, muscle contraction during stimulation is generated from two different sources, volitional contraction and external ES, which is referred as hybrid muscle activation. Although evidence of the neurorehabilitation via ES can enhance motor recovery, the rehabilitation efficacy related to the brain plasticity has not been well understood so far. In addition, there is also lack of research on studying the hybrid activation under dynamic movement such as cycling. The aim of this study is first to evaluate the cycling performance during ES-assisted cycling from electromyography (EMG) patterns of both limbs during cycling as well as the brain activity using near infrared spectroscopy (NIRS). Software and hardware implementation for extracting volitional and ES-induced EMG signals during cycling were used to assess the voluntary and ES-induced contraction during cycling movement. In addition to kinematical analysis of cycling performance, a novel neuroimage technique, near-infrared spectroscopy imaging (NIRI) has been utilized to detect cortical activation. The NIRS was used to detect the hemoglobin oxygenation (HbO) related to cortical activation during cycling with or without electrical stimulation conditions of health person. The cycling performance and cortical activation patterns were investigated in this study. Our results indicated that the reduced area value of volitional EMG LEs during cycling with ES provided evidence of effective hybrid muscle activation. The increased activations of supplementary motor area (SMA) and primary motor cortex (PMC) were found in hybrid activation cycling which may be related to the processing for the external stimulation to maintain the symmetry and smoothness movement in normal subjects. In the future study, the developed EMG, kinematic assessment as well as cortical activation using NIRI can be utilized as quantitative assessment measures to evaluate the rehabilitation of stroke patients from both limb motor functions and brain plasticity. The information obtained could provide patient-tailored therapeutic measures for the progress of stroke rehabilitation program based on the control strategy of cycling exercise under hybrid activation as well as the brain reorganization obtained from NIRI.

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