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BCI (Brain computer interface) is more popular in the neural engineering research one of the topics. BCI is in the human brain and a computer or other electronic device to establish a direct communication between the channels. Through this channel, in particular, the body can make up for lack of people with disabilities, through the manipulation of the brain to achieve device. Implement BCI in general, there are four parts:signal acquisition systems, signal processing systems, characteristics of the signal output system and feedback control system. The Brain Signals of the subject is cross-cutting science and computer science disciplines, there is great difficulty, take a long time of discussion and study.This thesis involves two parts:the brain signal acquisition and signal processing. The Brain Signals acquisition systems are analog front-end acquisition of the Brain Signals and the Brain Signals acquisition controller circuit components. Analog front-end circuit design is particularly important; its performance will affect the entire system. The Brain Signals is very weak, the noise can easily be covered, therefore, the circuit with a good signal to noise ratio and large enough gain. Analog front-end circuit consists of preamplifier, low pass filter circuit and back stage amplifier circuit, preamplifier circuit instrumentation amplifier is used because it has a high input impedance, high common mode rejection ratio (CMRR), low noise, and low drift. Single supply OPAMP mode, which can improve equipment reliability and help reduce system power types.The Brain Signals acquisition is part of PSOC3 microcontroller controller to achieve. PSOC3 integrates configurable analog and digital modules, with high precision, high bandwidth and flexibility and so on. We use the wealth of internal resources to achieve a multi-channel selection, analog-digital conversion, data processing, and USB data transmission. PC software using a LABVIEW, use it we realize the waveform display, digital signal filtering, noise reduction, spectral analysis.
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