I wanted to know whether the Eclipse can be used to do ABRs on children that are not sedated (e.g. a 4-year old looking at an iPad). Is sedation essential with children when using the Eclipse?
Answer: The Eclipse can do ABR and this procedure can, in principle, be applied to patients of any age.
This is fine, except that the vast majority of patients we see are not in the age group where awake ABRs are necessary. We typically see either infants who sleep naturally, or we see adults who can be relied upon to cooperate and lie still (and perhaps nod off). The children in the age group we are talking about here (let us say 2+ years) are less frequently seen for ABRs because most can perform behavioural testing quite easily (like VRA, play audiometry) and behavioural testing is always preferable to ABRs.
With ABR testing it is always easier to have a quiet (asleep) patient and far harder with an awake patient because of the greater myogenic noise (through movement and so on) which impacts negatively on the signal-to-noise ratio. If an ABR is definitely needed in a child at this age then one option is to do the test during periods of natural sleep (e.g. pay them a home visit in the evening and test the child when they are in natural sleep at home in bed) or if that does not work then it might be necessary in some cases to resort to sedation.
Aside from these ideas, there are a number of features on Eclipse that help to make recording in adverse recording conditions more practical.
If the noise is aperiodical, like movements when you have a patient who is not always lying completely still throughout the recording process then perhaps the most important feature to aid recording is the Bayesian weighted averaging. This will reduce the influence of sweeps that contain movement artefacts. In addition of course, you have the artefact reject options, which can be fine-tuned at any point during testing. Do not forget also that using the CE-Chirp® stimuli will maximise SNR, but through increased signal rather than decreased noise.
There is also the option of performing tests that do not rely on the patient being asleep, such as 40 Hz ASSR or the ALR (N1-P2 cortical evoked potentials) although this procedure is not usually applied to children below around 10 years old for threshold estimation as the response goes through a long maturational period through childhood and up to young adulthood.