Development of a multichannel bioinstrumentation system for human-computer interface applications
Özet
A multi-channel measurement system used to measure electrocardiogram (ECG),
electroencephalogram (EEG), electromyogram (EMG) and electrooculogram (EOG) biosignals has
been designed and prototyped. The designed system has 16 configurable measurement channels. Of the
16 channels the developed system has, 8 have been designed for EEG, 2 for EMG, 2 for EOG, 1 for
ECG measurements, the remaining 3 have been reserved as backup channels. In circuit design, biosignal
amplifier design principles have been applied by taking into account the characteristics of the biosignal
to be measured for each channel, such as bandwidth, frequency, amplitude, noise level. Modules such
as instrumentation amplifier, filter, DC suppression unit, amplifier, DC level determination unit, analog digital converter, optical isolation unit, power supply have been designed to perform biosignal
measurements through these channels. Biosignals measured by the developed system can be shifted to
the desired threshold level with the help of the analog output reference voltage, converted to digital data
10-bit resolution and transferred to the computer environment in real time. The data transferred to the
computer can be used in C#, Excel, MATLAB, and LabVIEW platforms. The novelty of the developed
system is that any of the four desired biosignal types can be measured from any channel. In addition,
another feature of the system is that it can work with real-time data without being dependent on the
databases serving for human-computer interface applications. In experimental studies with some
researchers for the performance tests of the system, ECG, EEG, EMG and EOG signals have been
recorded with different module configurations, and signal processing stages were carried out to be used
for human-computer applications.
