A new low-noise signal acquisition protocol and electrode placement for electrocochleography (ECOG) recordings.
Electrocochleography (ECOG) is a low-amplitude electrophysiological measurement technique primarily used as an assistive tool for the diagnosis of Ménière's disease. Of the two types of ECOG, transtympanic (TT) and extratympanic (ET), ET-ECOG has gained popularity due to its noninvasive nature; however, it suffers from increased susceptibility to various types of noise, due to the low-signal amplitude (~1 µV scale) associated with the method. Therefore, reliably obtaining ECOG recordings involves an environment that minimally interferes with the recording, a low-noise signal recorder, and a carefully executed recording protocol. We propose a new method that involves a modified ear electrode and electrode placement protocol that offers a solution to reducing noise in ET-ECOG. Noise suppression is achieved by minimizing background biological noise, and thermal noise from electrode impedances, which were identified to be the main contributors to signal degradation in ET-ECOG. Results show that the proposed method yields a >2.6 dB improvement in SNR in comparison with the conventional method (p < 0.05); thus, a SNR obtained with ~880 repetitions using conventional method can be achieved with ~360 repetitions. Improved SNR demonstrate that the proposed method is capable of achieving faster recordings, while maintaining similar or better SNR compared to conventional methods.
The Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, Canada.
Chathura
C
Kumaragamage
Brian
B
Lithgow
Zahra
Z
Moussavi
D000328:Adult; D001300:Audiometry, Evoked Response / Q000379:methods*; D004566:Electrodes; D005260:Female; D006801:Humans; D008297:Male; D012815:Signal Processing, Computer-Assisted; D059629:Signal-To-Noise Ratio; D055815:Young Adult