Fine-grain recordings of the electrically evoked compound action potential amplitude growth function in cochlear implant recipients

摘要

BackgroundIn cochlear implants (CI) measuring the electrically evoked compound action potential (ECAP) has become an important tool for verifying the electrode-nerve interface as well as establishing a basis for a map to program the speech processor. In a standard clinical setup recordings are averaged over 25–100 repetitions to allow for the detection of ECAPs within the noise floor. To obtain an amplitude growth function, these measurements are normally performed for 5–10 different stimulation levels. We evaluate a recording paradigm where the stimulation intensity is increased in quasi-continuous steps and instead of averaging repeated recordings with identical stimulation parameters, running averages over small intervals of stimulation levels are computed. The first visible nerve response was manually identified by two experts.