Pfurtscheller G, Druschky K, Kamp H D, Schwarz G, Litscher G, Rügheimer E, Neundörfer B, List W
Abteilung für Medizinische Informatik, Technischen Universität Graz.
EEG EMG Z Elektroenzephalogr Elektromyogr Verwandte Geb. 1987 Sep;18(3):108-14.
Multimodal EPs and heart rate variability-measurements in comatose patients have been performed for few years at the university hospitals of Graz and Erlangen. The following data and parameters are analysed and discussed: brainstem auditory evoked potentials, mechanical evoked long-latency SEP, VEP recorded over the central and occipital region and heart rate variability (HRV). The method of data acquisition and processing is described and normative data are introduced. For the long-latency EP-components a signal-to-noise-ratio (SNR) is calculated. SNR is defined as ratio of the largest EP peak-to-peak amplitude and the mean amplitude (standard deviation) of a period prior to the stimulation. An unmeasurable or questionable EP is defined when SNR less than 2.6. For the vertex-SEP the following mean +/- standard deviation was obtained: SNR = 10.6 +/- 4.6; the vertex VEP was calculated with SNR = 7.0 +/- 3.0. The SNR of the bipolar recorded occipitally VEP was 3.9 +/- 2.0. Heart rate variability measurements in normal persons revealed the following mean +/- standard deviation at a heart rate of 67.8/min +/- 10.8/min: HRV = 7.8% +/- 2.5%.
格拉茨和埃尔朗根的大学医院对昏迷患者进行多模态诱发电位和心率变异性测量已有数年。分析和讨论了以下数据和参数：脑干听觉诱发电位、机械诱发的长潜伏期体感诱发电位、在中央和枕区记录的视觉诱发电位以及心率变异性（HRV）。描述了数据采集和处理方法并引入了标准数据。对于长潜伏期诱发电位成分，计算信噪比（SNR）。SNR定义为刺激前一段时间内最大诱发电位峰峰值幅度与平均幅度（标准差）之比。当SNR小于2.6时，定义为不可测量或有问题的诱发电位。对于头顶体感诱发电位，得到以下平均值±标准差：SNR = 10.6 ± 4.6；头顶视觉诱发电位计算得出的SNR = 7.0 ± 3.0。枕部记录的双极视觉诱发电位的SNR为3.9 ± 2.0。正常人心率变异性测量在心率为67.8次/分钟±10.8次/分钟时显示以下平均值±标准差：HRV = 7.8% ± 2.5%。
