Objective To study the effects of long term application of cathartics on electromyography of rat colon, and to explore the role of interstitial cells of Cajal (ICC) in it. Methods Colonic slow waves of the rat was examined after 3-month feeding of phenolphthalein, and ICC in myenteric plexus was observed by ZIO method, and ultrastructure changes of nerves and ICC was observed. Results The frequency of slow waves of cathartic colon was reduced significantly(Ｐ＜0.05). The distribution of ICC in myenteric plexus was uneven, and the processes were mussily connected each other. Vacuolar degeneration of axon and ICC-like cells was revealed by electron microscope in myenteric plexus of cathartic colon. Conclusion Long term application of phenolphthalein could reduce the frequency of colonic slow waves, and the possible mechanism was degeneration of ICC and myenteric plexus nerves.
ObjectiveTo investigate the clinical features of Hirayama disease (HD). MethodsWe analyzed the clinical manifestations and assistant examination results of one patient with HD diagnosed in November, 2010. In addition, we reviewed the related literatures. ResultsThe patient was a young man, and the main symptoms were bilateral hand weakness with muscular atrophy. The muscle bundles trembled when he stretched his fingers. The electromyography showed neurogenic damage of both the thenar muscles and the first interosseous muscles. Brain magnetic resonance imaging (MRI) showed normal; cervical spine flexion MRI showed thinning cervical spinal cord with spinal canal narrowing at C5-C7 plane. In addition, epidural fat gap widened at C4-T1 plane, and enhanced scan showed cord-like changes, patchy strengthening and blood flow void shadow. ConclusionWhen asymmetric distal upper limb muscle weakness with muscle atrophy appears in adolescents, HD should be considered. The combination of neuroelectrophysiological examination and cervical spine flexion MRI scan is helpful for diagnosis. Wearing cervical collar may slow disease progression.
At present, fatigue state monitoring of upper limb movement generally relies solely on surface electromyographic signal (sEMG) to identify and classify fatigue, resulting in unstable results and certain limitations. This paper introduces the sEMG signal recognition and motion capture technology into the fatigue state monitoring process and proposes a fatigue analysis method combining an improved EMG fatigue threshold algorithm and biomechanical analysis. In this study, the right upper limb load elbow flexion test was used to simultaneously collect the biceps brachii sEMG signal and upper limb motion capture data, and at the same time the Borg Fatigue Subjective and Self-awareness Scale were used to record the fatigue feelings of the subjects. Then, the fatigue analysis method combining the EMG fatigue threshold algorithm and the biomechanical analysis was combined with four single types: mean power frequency (MPF), spectral moments ratio (SMR), fuzzy approximate entropy (fApEn) and Lempel-Ziv complexity (LZC). The test results of the evaluation index fatigue evaluation method were compared. The test results show that the method in this paper has a recognition rate of 98.6% for the overall fatigue state and 97%, 100%, and 99% for the three states of ease, transition and fatigue, which are more advantageous than other methods. The research results of this paper prove that the method in this paper can effectively prevent secondary injury caused by overtraining during upper limb exercises, and is of great significance for fatigue monitoring.
Aiming at the human-computer interaction problem during the movement of the rehabilitation exoskeleton robot, this paper proposes an adaptive human-computer interaction control method based on real-time monitoring of human muscle state. Considering the efficiency of patient health monitoring and rehabilitation training, a new fatigue assessment algorithm was proposed. The method fully combined the human neuromuscular model, and used the relationship between the model parameter changes and the muscle state to achieve the classification of muscle fatigue state on the premise of ensuring the accuracy of the fatigue trend. In order to ensure the safety of human-computer interaction, a variable impedance control algorithm with this algorithm as the supervision link was proposed. On the basis of not adding redundant sensors, the evaluation algorithm was used as the perceptual decision-making link of the control system to monitor the muscle state in real time and carry out the robot control of fault-tolerant mechanism decision-making, so as to achieve the purpose of improving wearing comfort and improving the efficiency of rehabilitation training. Experiments show that the proposed human-computer interaction control method is effective and universal, and has broad application prospects.
This paper studies the active force characteristics of the neck muscles under the condition of rapid braking, which can provide theoretical support for reducing the neck injury of pilots when carrier-based aircraft blocks the landing. We carried out static loading and real vehicle braking experiments under rapid braking conditions, collected the active contraction force and electromyography (EMG) signals of neck muscles, and analyzed the response characteristics of neck muscle active force response. The results showed that the head and neck forward tilt time was delayed and the amplitude decreased during neck muscle pre-tightening. The duration of the neck in the extreme position decreased, and the recovery towards the seat direction was faster. The EMG signals of trapezius muscle was higher than sternocleidomastoid muscle. This suggests that pilots can reduce neck injury by pre-tightening the neck muscles during actual braking flight. In addition, we can consider the design of relevant fittings for pre-tightening the neck muscles.