目的探讨抗N 甲基 D 天冬氨酸(NMDA)受体脑炎的临床特点和脑电图(electroencephalographic,EEG)表现。方法对34例抗NMDA受体脑炎的临床及EEG等资料进行回顾性分析。按病情轻重分为轻症组(13例)、重症组(21例),分析不同病情EEG特点。结...目的探讨抗N 甲基 D 天冬氨酸(NMDA)受体脑炎的临床特点和脑电图(electroencephalographic,EEG)表现。方法对34例抗NMDA受体脑炎的临床及EEG等资料进行回顾性分析。按病情轻重分为轻症组(13例)、重症组(21例),分析不同病情EEG特点。结果共纳入34例确诊的抗NMDA受体脑炎患者,其中31例出现精神症状,26例出现癫痫发作,11例出现意识障碍,6例出现运动障碍,8例患者因出现中枢性低通气需呼吸机辅助呼吸。EEG轻度异常5例,中度异常9例,重度异常16例;14例出现弥漫性慢波,8例出现全面性节律性δ活动(generalized rhythmic delta activity,GRDA),7例出现极度δ刷(extreme delta brush,EDB),12例出现癫痫样放电。重症组弥漫性慢波、GRDA及EDB图形出现率高于轻症组( P <0.05)。结论抗NMDA受体脑炎以精神症状、癫痫、意识障碍、运动障碍、中枢性低通气为主要临床表现。EEG对抗NMDA受体脑炎的诊断具有重要的意义。重症患者常出现较特异的GRAD和EDB图形。展开更多
Brain-computer interfaces(BCI)based on steady-state visual evoked potentials(SSVEP)have attracted great interest because of their higher signal-to-noise ratio,less training,and faster information transfer.However,the ...Brain-computer interfaces(BCI)based on steady-state visual evoked potentials(SSVEP)have attracted great interest because of their higher signal-to-noise ratio,less training,and faster information transfer.However,the existing signal recognition methods for SSVEP do not fully pay attention to the important role of signal phase characteristics in the recognition process.Therefore,an improved method based on extended Canonical Correlation Analysis(eCCA)is proposed.The phase parameters are added from the stimulus paradigm encoded by joint frequency phase modulation to the reference signal constructed from the training data of the subjects to achieve phase constraints on eCCA,thereby improving the recognition performance of the eCCA method for SSVEP signals,and transmit the collected signals to the robotic arm system to achieve control of the robotic arm.In order to verify the effectiveness and advantages of the proposed method,this paper evaluated the method using SSVEP signals from 35 subjects.The research shows that the proposed algorithm improves the average recognition rate of SSVEP signals to 82.76%,and the information transmission rate to 116.18 bits/min,which is superior to TRCA and traditional eCAA-based methods in terms of information transmission speed and accuracy,and has better stability.展开更多
A total of 127 adult patients who had sustained an impact of significant mechanical energy to their skulls during motor vehicle incidents were given thorough neuropsychological, cognitive and personality assessments b...A total of 127 adult patients who had sustained an impact of significant mechanical energy to their skulls during motor vehicle incidents were given thorough neuropsychological, cognitive and personality assessments between 0.5 years and 4 years after the event. Cross-sectional analysis indicated no statistically significant objective changes in patients as a function of yearly intervals. However there was strong evidence of significant deterioration of neuropsychological proficiency and efficiency between 0.3 to 1.0 years after the injury. A subset (n = 20) of patients who displayed moderately severe neuropsychological impairment when assessed about 1 year after the injury showed no statistically significant changes when reassessed about 1.5 years later (2.5 years after the brain trauma). These results challenge the traditional concept of “recovery” following a traumatic brain injury and indicate that insidious processes that adversely affect neurocognitive capacity may emerge 0.5 years after the trauma. Post-hoc analysis indicated that the occurrence of unconsciousness or its duration at the time of the injury minimally affected the magnitude of subsequent indices of neuropsychological impairment but influenced the incidence of electroencephalographic theta activity during the years following the injury.展开更多
A three op-amps instrumentation amplifier(I.A) is one of the most important segments in the electroencephalographic(EEG) acquisition system, which is used to suppress the interference of the common mode noise. However...A three op-amps instrumentation amplifier(I.A) is one of the most important segments in the electroencephalographic(EEG) acquisition system, which is used to suppress the interference of the common mode noise. However, electrode and op-amps offset voltages could saturate the I.A, so the ability of noise suppression for the I.A might be limited. To compensate for the electrode and op-amps offset voltages and improve the property of the I.A, the optical-isolated technology was used in the present study.This paper described the theory of DC suppression and employed the simulation software(i.e. Multisim10.0.) to demonstrate the constant<urrent source of the optical-isolated device comprised of general-purpose optocouplers.Using this technology we designed and tested an EEG acquisition system.During the test,a constant current was generated by the optocoupler(the MOTOROLA 4N35)when DC offset voltages from 0 to 15 mV were imposed on the input signal in the EEG acquisition system and the value of load resistance in the optical--isolated device was from 3 k to 15 kom.We also found that the IA with the gain of 857 could effectively reject a DC input rangeof±15mV.And An EEG signal is obtained by the EEG acquisition system,and a CMRR of 104.5 dB was achieved without trimmings.展开更多
文摘Brain-computer interfaces(BCI)based on steady-state visual evoked potentials(SSVEP)have attracted great interest because of their higher signal-to-noise ratio,less training,and faster information transfer.However,the existing signal recognition methods for SSVEP do not fully pay attention to the important role of signal phase characteristics in the recognition process.Therefore,an improved method based on extended Canonical Correlation Analysis(eCCA)is proposed.The phase parameters are added from the stimulus paradigm encoded by joint frequency phase modulation to the reference signal constructed from the training data of the subjects to achieve phase constraints on eCCA,thereby improving the recognition performance of the eCCA method for SSVEP signals,and transmit the collected signals to the robotic arm system to achieve control of the robotic arm.In order to verify the effectiveness and advantages of the proposed method,this paper evaluated the method using SSVEP signals from 35 subjects.The research shows that the proposed algorithm improves the average recognition rate of SSVEP signals to 82.76%,and the information transmission rate to 116.18 bits/min,which is superior to TRCA and traditional eCAA-based methods in terms of information transmission speed and accuracy,and has better stability.
文摘A total of 127 adult patients who had sustained an impact of significant mechanical energy to their skulls during motor vehicle incidents were given thorough neuropsychological, cognitive and personality assessments between 0.5 years and 4 years after the event. Cross-sectional analysis indicated no statistically significant objective changes in patients as a function of yearly intervals. However there was strong evidence of significant deterioration of neuropsychological proficiency and efficiency between 0.3 to 1.0 years after the injury. A subset (n = 20) of patients who displayed moderately severe neuropsychological impairment when assessed about 1 year after the injury showed no statistically significant changes when reassessed about 1.5 years later (2.5 years after the brain trauma). These results challenge the traditional concept of “recovery” following a traumatic brain injury and indicate that insidious processes that adversely affect neurocognitive capacity may emerge 0.5 years after the trauma. Post-hoc analysis indicated that the occurrence of unconsciousness or its duration at the time of the injury minimally affected the magnitude of subsequent indices of neuropsychological impairment but influenced the incidence of electroencephalographic theta activity during the years following the injury.
文摘A three op-amps instrumentation amplifier(I.A) is one of the most important segments in the electroencephalographic(EEG) acquisition system, which is used to suppress the interference of the common mode noise. However, electrode and op-amps offset voltages could saturate the I.A, so the ability of noise suppression for the I.A might be limited. To compensate for the electrode and op-amps offset voltages and improve the property of the I.A, the optical-isolated technology was used in the present study.This paper described the theory of DC suppression and employed the simulation software(i.e. Multisim10.0.) to demonstrate the constant<urrent source of the optical-isolated device comprised of general-purpose optocouplers.Using this technology we designed and tested an EEG acquisition system.During the test,a constant current was generated by the optocoupler(the MOTOROLA 4N35)when DC offset voltages from 0 to 15 mV were imposed on the input signal in the EEG acquisition system and the value of load resistance in the optical--isolated device was from 3 k to 15 kom.We also found that the IA with the gain of 857 could effectively reject a DC input rangeof±15mV.And An EEG signal is obtained by the EEG acquisition system,and a CMRR of 104.5 dB was achieved without trimmings.
