Background The brain death confirmation tests occupy a different position in each country＇s diagnostic criteria （or guideline）; the choices of tests are also different.China brain death criteria include clinical ju...Background The brain death confirmation tests occupy a different position in each country＇s diagnostic criteria （or guideline）; the choices of tests are also different.China brain death criteria include clinical judgment and confirmation tests.This study aimed to confirm the preferred confirmatory test and complementary confirmatory tests.Methods We did a clinical brain death determination on deep coma patients,and then divided them into brain death group and non-brain death group.According to the Chinese standards for determining brain death,both the groups accepted confirmatory tests including electroencephalograph （EEG）,somatosensory evoked potentials （SEP）,and transcranial Doppler （TCD）.The sensitivity,specificity,false positive rate,and false negative rate were calculated to evaluate the accuracy of the confirmatory tests.Results Among the 131 cases of patients,103 patients met the clinical criteria of brain death.Respiratory arrest provocation test was performed on 44 cases and 32 cases （73％） successfully completed and confirmed that they have no spontaneous breathing.Of the three confirmation tests,EEG had the highest completion rate （98％） and good sensitivity （83％） and specificity （97％）; TCD had followed completion rate （54％） and not good sensitivity （73％） and specificity （75％）; SEP had the lowest completion rate （49％）,good sensitivity （100％）,and not good specificity （78％）.After the combination of SEP or TCD with EEG,the specificity can increase to 100％.Conclusions The completion rate of respiratory arrest provocation test remains a problem in the clinical diagnosis of brain death.If the test cannot be completed,whether to increase a confirmatory test is debatable.SEP had an ideal sensitivity,and the specificity will reach 100％ after combining with TCD or EEG.When a confirmed test was uncertain,we suggest increasing another confirmatory test.展开更多
目的检测脓毒症脑病患者血清和脑脊液S100B浓度,探讨血清和脑脊液S100B浓度与脑电图严重程度的相关性。方法选择28例脓毒症脑病患者和10例普通脓毒症患者为研究对象,行脑电图检查,检测血清1 h S100B浓度、血清72 h S100B浓度、脑脊液72 ...目的检测脓毒症脑病患者血清和脑脊液S100B浓度,探讨血清和脑脊液S100B浓度与脑电图严重程度的相关性。方法选择28例脓毒症脑病患者和10例普通脓毒症患者为研究对象,行脑电图检查,检测血清1 h S100B浓度、血清72 h S100B浓度、脑脊液72 h S100B浓度,分析血清和脑脊液S100B浓度与脑电图严重程度的关系。结果脑病组患者血清1 h S100B浓度﹑血清72 h S100B浓度﹑脑脊液72 h S100B浓度均高于对照组(均P<0.05)。根据脑电图异常程度,将脓毒症脑病患者分为不同组别,血清1 h S100B浓度﹑血清72 h S100B浓度﹑脑脊液72 h S100B浓度均随脑电图严重程度增加而升高(均P<0.05)。结论血清和脑脊液S100B浓度可作为脓毒症脑病患者脑损害严重程度的评估指标。展开更多
In this paper, tempo perception is investi- gated by recording spontaneous electroencephalograph （EEG）. Ten normal male non-musician college students are selected according to questionnaire results after listening a...In this paper, tempo perception is investi- gated by recording spontaneous electroencephalograph （EEG）. Ten normal male non-musician college students are selected according to questionnaire results after listening absorbedly to four different tempos of an excerpt from a Mozart sonata. EEGs data are recorded when the subjects are listening to the music. The EEG spectral power （SP） is analyzed for alpha band. The varying trend of power spectrum during exposure to music excerpts of different tempos is studied and shows the consistence with the previous tempo-specific hypothesis： a tempo-transformed performance will sound less natural than an original performance does. The results presented in this paper suggest that tempo is an important factor that could influence the alpha rhythm.展开更多
目的研究视觉对人体姿势控制影响及其脑功能网络连接机制。方法以15名健康青年为研究对象,要求受试者分别进行30 s睁眼、闭眼的双腿站立平衡,采集平衡过程中身体压力中心(center of pressure,COP)和脑电。对COP进行样本熵(SampleEn)计算...目的研究视觉对人体姿势控制影响及其脑功能网络连接机制。方法以15名健康青年为研究对象,要求受试者分别进行30 s睁眼、闭眼的双腿站立平衡,采集平衡过程中身体压力中心(center of pressure,COP)和脑电。对COP进行样本熵(SampleEn)计算;对脑电θ、α和β频段,计算相位滞后指数(phase lag index,PLI)构建大脑功能网络,并基于图论计算集聚系数(C)、特征路径长度(L)及小世界网络属性(σ)。结果人体在双腿站立平衡过程中,闭眼COPY样本熵显著高于睁眼(P<0.05)。闭眼α频段PLI平均值显著高于睁眼(P<0.05);闭眼α频段C、σ显著高于睁眼,L显著低于睁眼(P<0.05)。闭眼时α频段额区-中央区-顶区之间的网络连接以及中央区和顶区内连接强度显著高于睁眼(P<0.05)。闭眼时α频段PLI平均值以及C值与COPY样本熵中度呈中度负相关(P<0.05)。睁眼时左前额区、左顶区、左枕区α频段PLI平均值与COPY样本熵呈中度负相关;闭眼时左中央区、右枕区α频段PLI平均值则与COPY样本熵呈中度负相关。结论人体在站立平衡时,当没有视觉信息输入时,身体平衡稳定性下降,同时伴随着脑电α频段的脑网络连接增强以及大脑处理信息的效率需提升。人体在不同的视觉条件下进行姿势控制时,大脑会采用不同的神经策略。展开更多
针对小波硬阈值去噪算法在脑电信号去噪过程中会导致部分有效信号丢失的不足,提出基于中介真值程度度量(Measuring of Medium Truth Degree,MMTD)与小波硬阈值相结合的脑电信号去噪(MMTD and Wavelet Hard-threshold,MAWH)方法。该算法...针对小波硬阈值去噪算法在脑电信号去噪过程中会导致部分有效信号丢失的不足,提出基于中介真值程度度量(Measuring of Medium Truth Degree,MMTD)与小波硬阈值相结合的脑电信号去噪(MMTD and Wavelet Hard-threshold,MAWH)方法。该算法的基本思想是采用小波变换对含噪信号进行分解,对分解后的各层高频小波系数进行阈值处理,对处理后的小波系数重构,以达到消噪的目的。通过仿真试验,采用经典的RMSE、SNR评价标准,将MAWH方法与典型的硬、软两种阈值法进行比较。结果表明,在不同的噪声强度下,MAWH去噪方法对脑电信号的去噪效果更加优越。展开更多
文摘Background The brain death confirmation tests occupy a different position in each country＇s diagnostic criteria （or guideline）; the choices of tests are also different.China brain death criteria include clinical judgment and confirmation tests.This study aimed to confirm the preferred confirmatory test and complementary confirmatory tests.Methods We did a clinical brain death determination on deep coma patients,and then divided them into brain death group and non-brain death group.According to the Chinese standards for determining brain death,both the groups accepted confirmatory tests including electroencephalograph （EEG）,somatosensory evoked potentials （SEP）,and transcranial Doppler （TCD）.The sensitivity,specificity,false positive rate,and false negative rate were calculated to evaluate the accuracy of the confirmatory tests.Results Among the 131 cases of patients,103 patients met the clinical criteria of brain death.Respiratory arrest provocation test was performed on 44 cases and 32 cases （73％） successfully completed and confirmed that they have no spontaneous breathing.Of the three confirmation tests,EEG had the highest completion rate （98％） and good sensitivity （83％） and specificity （97％）; TCD had followed completion rate （54％） and not good sensitivity （73％） and specificity （75％）; SEP had the lowest completion rate （49％）,good sensitivity （100％）,and not good specificity （78％）.After the combination of SEP or TCD with EEG,the specificity can increase to 100％.Conclusions The completion rate of respiratory arrest provocation test remains a problem in the clinical diagnosis of brain death.If the test cannot be completed,whether to increase a confirmatory test is debatable.SEP had an ideal sensitivity,and the specificity will reach 100％ after combining with TCD or EEG.When a confirmed test was uncertain,we suggest increasing another confirmatory test.
文摘目的检测脓毒症脑病患者血清和脑脊液S100B浓度,探讨血清和脑脊液S100B浓度与脑电图严重程度的相关性。方法选择28例脓毒症脑病患者和10例普通脓毒症患者为研究对象,行脑电图检查,检测血清1 h S100B浓度、血清72 h S100B浓度、脑脊液72 h S100B浓度,分析血清和脑脊液S100B浓度与脑电图严重程度的关系。结果脑病组患者血清1 h S100B浓度﹑血清72 h S100B浓度﹑脑脊液72 h S100B浓度均高于对照组(均P<0.05)。根据脑电图异常程度,将脓毒症脑病患者分为不同组别,血清1 h S100B浓度﹑血清72 h S100B浓度﹑脑脊液72 h S100B浓度均随脑电图严重程度增加而升高(均P<0.05)。结论血清和脑脊液S100B浓度可作为脓毒症脑病患者脑损害严重程度的评估指标。
基金supported by the National Natural Science Foundation of China under Grant No. 60736029, 30525030, 30570474, and 30870655.
文摘In this paper, tempo perception is investi- gated by recording spontaneous electroencephalograph （EEG）. Ten normal male non-musician college students are selected according to questionnaire results after listening absorbedly to four different tempos of an excerpt from a Mozart sonata. EEGs data are recorded when the subjects are listening to the music. The EEG spectral power （SP） is analyzed for alpha band. The varying trend of power spectrum during exposure to music excerpts of different tempos is studied and shows the consistence with the previous tempo-specific hypothesis： a tempo-transformed performance will sound less natural than an original performance does. The results presented in this paper suggest that tempo is an important factor that could influence the alpha rhythm.
文摘目的研究视觉对人体姿势控制影响及其脑功能网络连接机制。方法以15名健康青年为研究对象,要求受试者分别进行30 s睁眼、闭眼的双腿站立平衡,采集平衡过程中身体压力中心(center of pressure,COP)和脑电。对COP进行样本熵(SampleEn)计算;对脑电θ、α和β频段,计算相位滞后指数(phase lag index,PLI)构建大脑功能网络,并基于图论计算集聚系数(C)、特征路径长度(L)及小世界网络属性(σ)。结果人体在双腿站立平衡过程中,闭眼COPY样本熵显著高于睁眼(P<0.05)。闭眼α频段PLI平均值显著高于睁眼(P<0.05);闭眼α频段C、σ显著高于睁眼,L显著低于睁眼(P<0.05)。闭眼时α频段额区-中央区-顶区之间的网络连接以及中央区和顶区内连接强度显著高于睁眼(P<0.05)。闭眼时α频段PLI平均值以及C值与COPY样本熵中度呈中度负相关(P<0.05)。睁眼时左前额区、左顶区、左枕区α频段PLI平均值与COPY样本熵呈中度负相关;闭眼时左中央区、右枕区α频段PLI平均值则与COPY样本熵呈中度负相关。结论人体在站立平衡时,当没有视觉信息输入时,身体平衡稳定性下降,同时伴随着脑电α频段的脑网络连接增强以及大脑处理信息的效率需提升。人体在不同的视觉条件下进行姿势控制时,大脑会采用不同的神经策略。
文摘针对小波硬阈值去噪算法在脑电信号去噪过程中会导致部分有效信号丢失的不足,提出基于中介真值程度度量(Measuring of Medium Truth Degree,MMTD)与小波硬阈值相结合的脑电信号去噪(MMTD and Wavelet Hard-threshold,MAWH)方法。该算法的基本思想是采用小波变换对含噪信号进行分解,对分解后的各层高频小波系数进行阈值处理,对处理后的小波系数重构,以达到消噪的目的。通过仿真试验,采用经典的RMSE、SNR评价标准,将MAWH方法与典型的硬、软两种阈值法进行比较。结果表明,在不同的噪声强度下,MAWH去噪方法对脑电信号的去噪效果更加优越。
