Description
9
1.2. Principle of Operation
The principle of operation is based on the recording and input of bio-potentials and
other physiological signals to computer and their further processing and analysis.
The block diagram of the system is shown in Fig. 1.
Fig. 1. The
Neuro-Audio
system
Biopotentials from the electrodes are transferred to the amplifiers, where they are
amplified and then digitized by the analog-digital converter (ADC) delivered
to the digital signal processor (DSP) via 4000 V galvanic isolation. The DSP controls
the operation of the amplifiers and ADC via 4000 V galvanic isolation.
The unit microcontroller (MC) provides the connection between DSP of the module
and the computer via USB. The DSP generates audio stimulator signal in a digital
form which is converted to the analogous form by the digital-analogue converter
(DAC). Then, the signal is amplified by the audio amplifier and delivered
to the auditory stimulator. If there is a bone conduction amplifier, the signal
is delivered from the audio amplifier output. Then, the amplified signal is delivered
to the bone vibrator. Besides, the unit microcontroller receives trig-in signals and
synchronizes them with the data flow from ADC.
The bone conduction amplifier is powered via mains-operated medical power supply
unit (PSU-9) or built-in batteries.
The galvanically isolated part of the amplifier unit (the amplifier module) is powered
via galvanically isolated DC converter of the power supply unit (PSU).
The digital system operates under control of PC (IBM PC type) with a mouse,
keyboard, laser or jet printer and installed licensed Windows OS. Using PC,