Maico MB 11 Classic, Руководство по эксплуатации

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Operation Manual MB 11 Classic
8100498-4_OM_MB11_Classic_3.18_EN_16a.docx 6 01/16
3 Description
MB 11 tests hearing function by measuring the brainstem auditory evoked
response of the auditory pathway. Processing of EEG samples allows the
auditory brainstem response generated by the delivery of the acoustic
stimulus and present in the EEG to be differentiated from generalized EEG
activity.
3.1 Auditory Brainstem Response (ABR) audiometry
Brainstem potentials, BERA (brainstem evoked response audiometry) or ABR
(auditory brainstem response), are optimally measured on a quiet, sleeping
patient. In fact, sleep is conducive to improving the quality of the recording
and reducing test time.
3.2 The MB 11 Classic
The MB11 Classic uses standard disposable
electrodes to record an auditory brainstem
response (ABR). Insert earphones are used to
deliver the acoustic stimulus.
The MB11 performs a fixed intensity (35 dB nHL)
ABR screening. It is particularly suited for
newborn hearing screening.
3.3 Automatic Screening with the "Fast
Steady State Algorithm”
The acoustical CE-Chirp stimulus is presented at a high repetition rate
(93/second). At this rate a so-called "
S teady- S tate R esponse" ( SSR ) occurs.
The objective statistical determination of the presence of the SSR is
performed after the EEG is processed to determine its frequency content.
The SSR is described in the frequency domain by a few spectral lines
(harmonics), mathematically related to the stimulus rate of 93 Hz. The
statistical test uses the phase and amplitude information of the harmonics
below 1200 Hz. Frequencies in the processed EEG that are not related to the
stimulus rate contain no response to the auditory stimulus, but only contain
generalized EEG activity or “noise”. These spectral lines will not be
considered in the test result. This signal detection algorithm is associated
with short test times as well as high immunity against distortion from
electrical interference.
Figure 1
Testing with MB11 Classic