Otodynamics Otoport Flex - Pass Criteria and Ear Cup Settings

Otoport OAE+ABR
User Manual for Otoport DP+TE model
131
Conguration
Stim Type
Stim type sets the stimulus type used in the ABR test. The types available
are ‘click’ and ‘chirp’. See chapter 26 Mode of operation for further details
of these stimulus types. The chirp stimulus has been demonstrated to
give a larger ABR response for the same stimulus level. Stim Type is
congurable only in ABRcustom, default is chirp in both modes.
Start
If Start is ON then the ABR test will proceed from the Impedance Check
screen to data collection (autostart) without any action from the tester if test
conditions are good.
If Start is OFF the tester determines when to proceed from Impedance
Check to data collection (manual start).
Start is congurable only in ABRcustom, default is ON in both modes.
Stop
The Stop setting controls whether the test automatically stops when the
pass criteria are met. If Stop is turned OFF, the test will run for longer,
but the ABR levels will be more accurately measured. If Stop is ON when
screening, the test will be as short as possible.
Stop is congurable only in ABRcustom, default is ON in both modes.
Pass criteria
Pass criteria sets the conditions in which the ABR test will give a pass
result.
Pass criteria is based on a statistical measure similar to signal to noise
ratio known as Fsp, and a measure of the extent to which the averaged
response waveform resembles a typical neonate ABR, a value referred to
as template correlation (TC).
Fsp is the principle determinant of a Pass. It must achieve a minimum
xedFspor dynamicFsplevel. The dynamicFsp threshold rises if
power line noise is a large part of the electrical noise measured in order
to account for any possible contribution of the powerline noise to Fsp
(to ensure that the powerline noise is not mistaken for an ABR). The
minimum xedFsp threshold is higher than the largest Fsp ever likely to be
achieved by chance in EEG noise.
The minimum TC requirement should be achieved when recording an ABR
waveform from a neonate (34 weeks to 6 months gestational age). The
strict TC requirement is higher than largest TC ever likely to be achieved by
power line interference.