Southern General Hospital, Glasgow, UK.
Br J Anaesth. 2013 Sep;111(3):400-5. doi: 10.1093/bja/aet067. Epub 2013 Mar 26.
Depth of anaesthesia (DOA) monitors based on the electroencephalogram (EEG) are commonly used in anaesthetic practice. Their technology relies on mathematical analysis of the EEG waveform, generally resulting in a number which corresponds to anaesthetic depth. We have created a novel method of interpreting the EEG, which retains its underlying complexity. This method consists of turning the EEG into a sound: the electroencephalophone (EEP).
In a pilot study, we recorded awake and anaesthetized EEGs from six patients. We transformed each EEG into an audio signal using a ring buffer with a write frequency of 1 kHz and a read frequency of 48 kHz, thus elevating all output frequencies by a factor of 48. In essence, the listener hears the previous 12 s of EEG data compressed into 250 ms, updated every 250 ms. From these data, we generated a bank of 5 s audio clips, which were then used to train and test a sample of 23 anaesthetists.
After training, 21 of the 23 anaesthetists were able to use the EEP to correctly identify the conscious state of >5 of 10 randomly selected patients (P<0.001). The median score was 8 out of 10, with an inter-quartile range of 7-9.
The EEP shows promise as a DOA monitor. However, extensive validation would be required in a variety of clinical settings before it could be accepted into mainstream clinical practice.
基于脑电图（EEG）的麻醉深度监测仪在麻醉实践中被广泛使用。其技术依赖于对 EEG 波形的数学分析，通常会产生一个与麻醉深度相对应的数值。我们创造了一种新的 EEG 解释方法，保留了其底层的复杂性。该方法将 EEG 转化为声音：脑电图仪（EEP）。
在一项初步研究中，我们记录了六名患者清醒和麻醉时的 EEG。我们使用一个环形缓冲区将每个 EEG 转换为音频信号，其写频率为 1 kHz，读频率为 48 kHz，从而将所有输出频率提高 48 倍。从本质上讲，听众听到的是 EEG 数据的前 12 s 被压缩到 250 ms 中，每 250 ms 更新一次。从这些数据中，我们生成了一组 5 s 的音频剪辑，然后使用这些剪辑来培训和测试 23 名麻醉师样本。
经过培训，23 名麻醉师中有 21 名能够使用 EEP 正确识别 >5 名随机选择患者中的意识状态（P<0.001）。中位数得分为 10 分中的 8 分，四分位距为 7-9 分。
EEP 有望成为一种麻醉深度监测仪。然而，在各种临床环境中需要进行广泛的验证，然后才能被接受进入主流临床实践。
