Bc Assr; Incorrect Detection By Transducer Induced Electromagnetic Interference (Emi) - Interacoustics Eclipse Additional Information

Eclipse Additional Information Page 151
6.9

BC ASSR

The ASSR threshold can be tested with the bone conductor to examine if a patient is having a conductive
hearing loss. The transducer selection can be changed during the measurement from the temporary setup
(see below).
From the left panel of the user interfaces it will now be indicated that the selected transducer is a bone con-
ductor.
Note Using the Bone conductor does not give access to 500Hz.

6.9.1 Incorrect detection by transducer induced ElectroMagnetic Interference (EMI)

A general point of concern in all electrophysiology measurements is artifacts. This is typically caused by the
electrical signal to transducers that may provoke electrically introduced artifacts into the electrodes / elec-
trode leads, and this will cause irregular ABR waveforms (ABR) or false response detection in ASSR.
Clinical personnel must always use common sense based on the nature of electrophysiological responses
and the relevant mechanisms involved, when performing and evaluating electrophysiological test results to
avoid or identify artifactual responses.
At high intensities towards the output limitations of the transducers (particularly above 80dBnHL air conduc-
tion and 40dBnHL Bone conductors) the EMI is large, and there is an increased risk of cross talk interference
from transducers to electrodes and recording cables.
The picture below is an example of a rejection due to electrical artifacts for a high intensity provided by the
bone conductor.