Development and validation of a low noise signal acquisition protocol for inner ear evoked potentials
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Abstract
A low noise signal acquisition protocol is required for inner ear evoked response recordings. In this work, a parallel amplifier approach was investigated to implement a bio-signal amplifier with low voltage noise (<5nV/√Hz), and low current noise (~2fA/√Hz). A modified ear electrode was investigated to reduce biological interference and thermal noise due to high impedance electrodes. A physical model to simulate electrical activity of the inner ear was developed to evaluate the accuracy of detecting vestibular field potentials (FPs) in the presence of various noise sources. Muscle activity and noise generated from the recording apparatus were found to be the dominating sources, degrading performance of FP extraction. Contributions from this work include: the design, implementation, and validation of a bio-signal amplifier with <5nV/√Hz voltage noise, and a low impedance electrode development and placement protocol. As a result, a signal-to-noise-ratio improvement of ~11dB (compared to the current protocol) was achieved.