A proof of concept evaluation of the electroencephalophone as a discriminator between wakefulness and general anaesthesia

Glen, J., Porr, B., Hamilton, R. and Tait, L. (2013) A proof of concept evaluation of the electroencephalophone as a discriminator between wakefulness and general anaesthesia. British Journal of Anaesthesia, (doi:10.1093/bja/aet067)

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Abstract

Background 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). Methods In a pilot study, we recorded awake and anaesthetised EEGs from 6 patients. We transformed each EEG into an audio signal using a ring buffer with a write frequency of 1KHz and a read frequency of 48KHz, thus elevating all output frequencies by a factor of 48. In essence, the listener hears the previous 12 seconds of EEG data compressed into 250ms, updated every 250ms. From this data we generated a bank of 5-second audio clips, which were then used to train and test a sample of 23 anaesthetists. Results Following training, 21/23 anaesthetists were able to use the EEP to correctly identify the conscious state of greater than 5 out of 10 randomly selected patients (p<0.001). The median score was 8 out of 10, with an interquartile range of 7-9. Conclusions 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.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Hamilton, Dr Roderick and Porr, Dr Bernd
Authors: Glen, J., Porr, B., Hamilton, R., and Tait, L.
Subjects:R Medicine > RC Internal medicine > RC0321 Neuroscience. Biological psychiatry. Neuropsychiatry
T Technology > TK Electrical engineering. Electronics Nuclear engineering
College/School:College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
College of Science and Engineering > School of Engineering > Biomedical Engineering
Journal Name:British Journal of Anaesthesia
Publisher:Oxford University Press
ISSN:0007-0912
Published Online:26 March 2013

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