Effect of Yi Jin Jing (Sinew-transforming Qigong Exercises) on skeletal muscle strength in the elderly / 针灸推拿医学（英文版）

Objective: To observe the effect of Yi Jin Jing (Sinew-transforming Qigong Exercises) on the muscle strength in senile sarcopenia. Methods: Sixty-five old people with sarcopenia were randomized into Yi Jin Jing group and a blank control group. Thirty-three patients in Yi Jin Jing group practiced Yi Jin Jing (Sinew-transforming Qigong Exercises), while 32 patients in the blank control group didn't receive any interventions. The muscle strength was measured before and after 12-week training. Results: During the study, each group had 1 dropout. The muscle strength was improved after 12-week training in Yi Jin Jing group, and the difference was statistically significant (P<0.05); there was no significant difference in the blank control group (P>0.05). After the intervention, there was a significant difference between Yi Jin Jing group and the blank control group in comparing the muscle strength (P<0.05). Conclusion: Constant Yi Jin Jing (Sinew-transforming Qigong Exercises) training can notably improve skeletal muscle strength in senile sarcopenia.

Correlation of restenosis after rabbit carotid endarterectomy and inflammatory cytokines

OBJECTIVE@#To establish rabbit model of restenosis after carotid endarterectomy surgery, and to study tissue inflammatory cytokines (TNF-α, IL-6) involved in restenosis.@*METHODS@#A total of 32 rabbits were randomly divided into two groups: model group and control group. The right common carotid artery in rabbits was damaged by carotid endar terectomy in model group. The tissues were harvested at different time points respectively, the pathological changes of the vascular wall after operation were observed at different time points. The changes of expression of tissue vascular wall inflammatory cytokines (TNF-α, IL-6) at different time points after the surgery was observed by RT-PCR, and the changes of serum inflammatory cytokines (TNF-α, IL -6) were detected by ELISA.@*RESULTS@#The new intima appeared after 7 days of the injury and reached the peak on 28 d which is uneven and significantly thicker than the control group (P<0.01). The tissue inflammatory cytokines (TNF-α, IL-6) were significantly increased after the rabbit common carotid artery injury, which was significant difference compared with normal control group (P<0.05).@*CONCLUSIONS@#The tissue inflammatory factors significantly increase after the rabbit carotid artery injury, which suggests the mutual concurrent effects of inflammatory cytokines can result in the proliferation of vascular restenosis.

Surface electromyogram denoising using adaptive wavelet thresholding / 生物医学工程学杂志

Surface electromyogram (sEMG) may have low signal to noise ratios. An adaptive wavelet thresholding technique was developed in this study to remove noise contamination from sEMG signals. Compared with convention- al wavelet thresholding methods, the adaptive approach can adjust thresholds based on different signal to noise ratios of the processed signal, thus effectively removing noise contamination and reducing distortion of the EMG signal. The advantage of the developed adaptive thresholding method was demonstrated using simulated and experimental sEMG recordings.

Research on surface electromyographic signal decomposition based on the level of contraction force / 生物医学工程学杂志

Aiming at the difficulty of surface electromyography (SEMG) signal decomposition, we in this paper proposed a method of gradual processing based on contraction force level of muscle. At first, SEMG signals were recorded at different levels of muscle contraction force. Then, the SEMG data recorded at minimum level of contraction force were decomposed adopting the conventional methods. Further, the data at higher level of contraction force was decomposed using the templates and inter-pulse interval (IPI) information resulted from the previous composition performed at lower level of contraction force. Such procedure was iteratively performed level by level until the SEMG data at the maximal level of contraction force were successfully decomposed. The experimental results showed that the proposed method was effective in decomposing SEMG data, offering a valuable solution to the difficulty in obtaining templates at relatively high level of muscle contraction force. The complexity of SEMG decomposition in the case of high level of contraction force could also be reduced to a certain extent by using the proposed method.

Identification of Model Parameters Basing on Matched Processing between Simulated and Recorded sEMG Signals / 航天医学与医学工程

Objective To identify the model parameters of surface Electromyography (sEMG) by comparison between simulated and recorded signals. Methods A physiological model of sEMG signal was established basing on several logical hypothetical conditions, such as motor unit action potentials (MUAP), motor unit recruitment and firing behavior caused by excitation, architecture of volume conductor and other simulated factors. According to the matched shapes between the simulated and recorded sEMG signals, a group of model parameters was obtained; according to the similar power spectrum variations of real sEMG signals, decreased muscle fiber conduction velocity (MFCV) was applied to simulate the sEMG signals of the fatigued muscle. Results The experimental results showed that the simulated superimposed MUAP shapes could be matched with the recorded MUAPs satisfactorily by adjusting some proper physiological parameters of the model. When the MFCV of each fiber was assumed to decrease, the mean and median frequency (MNF, MDF) of the simulated sEMG signals declined, and this phenomenon was very similar to that of the recorded sEMG signals and could be used to interpret the muscle fatigue process. Conclusion This model provides an effective approach to simulate real sEMG signals, and the simulated signals can also be used to help the analysis of recorded sEMG signals.

Quantitative relationship between needle electrode electromyography signal of AR model parameter and local muscular fatigue / 中国组织工程研究

BACKGROUND: Research on muscular fatigue has extensive value of application in fundamental research about neuromuscular system, handicapped rehabilitation engineering, objective evaluation on physiotherapeutic effect, scientific training of athletes and ergonomics etc.OBJECTIVE: To study partial muscular fatigue by using AR model parameter of needle electrode electromyography (NEMG) signal and try to reveal the quantitative relationship between local muscular fatigue process and AR model coefficient of NEMG signal.DESIGN: Human NEMG signal was taken as the subject, the changing rule of myoelectric characteristics parameter in local muscular fatigue process was studied.SETTING: NML Laboratory of China University of cience and Technology.PARTICIPANTS: 4 eases of NEMG signals were obtained from NEMG signal collection system manufactured by NML Laboratory of China University of Science and Technology. Four volunteers that selected were healthy males and their tibialis anterior muscles were tested.METHODS: Based on the theory of random signal parameter model,NEMG signals were modeled and parameter was selected, the trend of parameter of NEMG signal changing with the time increasing was studied in the muscular fatigue process. Relative programs from MATLAB language toolbox were adopted for programming.MAIN OUTCOME MEASURES: The trend of α1 parameter of NEMG signal changing with the time (fatigue process) increasing. RESULTS: There was a correlation between local museular fatigue of human body and the changing trend of α1 parameter of NEMG signal tested from the muscle, that is, α1 parameter of NEMG signal increased with the time (fatigue process) increasing.CONCLUSION: By means of the increasing trend of α1 parameter of NEMG signal with the time (fatigue process) increasing, muscular fatigue state can be better evaluated.

Study of the average FR of the MUAP's in a couple of agonist-antagonist muscles / 生物医学工程学杂志

"Common Drive" is presented recently as a new concept used to explore the control mechanism of neuromuscular system. In this paper, the average firing rate (FR) of the motor unit action potential (MUAP) is estimated by means of decomposition technique for needle electromyographic (NEMG) signals obtained from elbow joint agonist-antagonist muscle pair with constant contraction force. The change tendency and correlation of the average FR with time are studied. The results of the experiment show that, no matter flexion or extension of the elbow joint, the average FR of both motor units(MUs) in the couple of agonist and antagonist descends with time, and the variations of their amplitude and fluctuation are highly correlated. This indicates that when two antagonist muscles are activated simultaneously to stiffen a joint, the nervous system views them as one unit and controls them in similar fashion. It also confirms the existence of "Common Drive" phenomenon at joint level.