Recognition of motor imagery electroencephalogram based on flicker noise spectroscopy and weighted filter bank common spatial pattern / 生物医学工程学杂志

Due to the high complexity and subject variability of motor imagery electroencephalogram, its decoding is limited by the inadequate accuracy of traditional recognition models. To resolve this problem, a recognition model for motor imagery electroencephalogram based on flicker noise spectrum (FNS) and weighted filter bank common spatial pattern ( wFBCSP) was proposed. First, the FNS method was used to analyze the motor imagery electroencephalogram. Using the second derivative moment as structure function, the ensued precursor time series were generated by using a sliding window strategy, so that hidden dynamic information of transition phase could be captured. Then, based on the characteristic of signal frequency band, the feature of the transition phase precursor time series and reaction phase series were extracted by wFBCSP, generating features representing relevant transition and reaction phase. To make the selected features adapt to subject variability and realize better generalization, algorithm of minimum redundancy maximum relevance was further used to select features. Finally, support vector machine as the classifier was used for the classification. In the motor imagery electroencephalogram recognition, the method proposed in this study yielded an average accuracy of 86.34%, which is higher than the comparison methods. Thus, our proposed method provides a new idea for decoding motor imagery electroencephalogram.

Effect of receptor antagonist of interleukin-6 on edema of spinal cord / 中国组织工程研究

BACKGROUND: Researches indicate that interleukin-6 (IL-6) in blood has changed during the process of the edema and infection of spinal cord.It is found that IL-6 participates in the course of spinal cord lesion according to the further researches. It is also presumed that the IL-6 is correlated with the edema of spinal cord accompanied nervous system diseases.OBJECTIVE: To observe the effect of the receptor antagonist of the IL-6 on the traumatic edema of spinal cord, and explore the effect of IL-6 in the process of the edema of spinal cord.DESIGN: Randomized control experiment with animals as subjects.SETTING: Department of Orthopedic, Hospital Affiliated to Guangdong Medical College.MATERIALS: The experiment was completed from January to December 2004 in the Animal Experimental Center of Guangdong Medical College.Forty male Wistar rats were selected and randomly divided into the normal group, the wound group, the saline control group and the receptor antagonist of the IL-6 treated group with 10 rats in each group.METHODS: ① The receptor antagonist of the IL-6 treated group: Blast injury of the thoracic spinal cord was made by the sap pressure, and the injection with the receptor antagonist of the IL-6 was given at the injured region with microinjector. ② The wound group: There was not the procedure of administration and placement of the tube. ③ The saline control group: The IL-6 was replaced with the sterile-physiological saline solution (SPSS), and the other procedures were the same as those of the receptor antagonist of the IL-6 treated group. ④ The normal group: There was not any treatment. All rats in each group were detected with magnetic resonance. The water content in the spinal cord was determined with the dry and humid weight method, and the status of the edema of spinal cord was observed with the electron microscope and the pathological image analysis after dyeing with hematine-eosine.MAIN OUTCOME MEASURES: ① The results of the examination of the rats in each group with the magnetic resonance. ② The water content in the spinal cord of rats in each group. ③ The status of the edema of spinal cord was observed with the electron microscope and the pathological image analysis.RESULTS: All the 40 rats entered the result analysis. ① The edema of the T2 w eighting image in the receptor antagonist of the IL-6 treated group was relieved as compared with that in the wound group and the saline control group. ② The water content of the injured region in the receptor antagonist of the IL-6 treated group, the wound group and the saline control group was higher than that in the normal group [ (81.68±1.39)%, (79.72±1.49)%, (82.59±1.12)%, (77.19±0.64)% ,P ＜ 0.01].The water content of the injured region in the wound group was higher than that in the normal group(P ＜ 0.01), and the receptor antagonist of the IL-6 treated group was lower than that of the wound group (P ＜ 0.01). ③The cell body of the gray substance was contracted, the inter-space around the cell was enlarged and the nerve cells were lost in the wound group;The saline control group was not significantly different as compared with the wound group; The cellular edema, degeneration and the necrosis in the receptor antagonist of the IL-6 treated group was milder than that in the wound group.CONCLUSION: The receptor antagonist of the IL-6 has the therapeutical effect on the traumatic edema of spinal cord. The endogenous IL-6 participates in the development of the traumatic edema of spinal cord.