Design And Implementation Of Polysomnography And Evaluation System

With the acceleration of people’s life rhythm and the increase of life pressure,sleep problem has gradually become a hot topic of social concern.Therefore,efficient and high-quality collection of sleep bioelectrical signals is very important for sleep monitoring and curing related sleep diseases.However,the performance of foreign multi-channel sleep monitoring equipment is good but the price is relatively high,while the price of domestic equipment is relatively low but the performance is difficult to guarantee,which increases the difficulty of obtaining sleep physiological signals with high quality;at the same time,it is difficult for the data collector to accurately obtain the stable operation state of the acquisition equipment and the impact of environmental noise,which makes the efficiency and quality of data acquisition difficult to be guaranteed.Therefore,the design and development of polysomnography and evaluation system which based on the American Society of Sleep Medicine standards and design requirements has effectively improved the efficiency and reliability of polysomnographic bioelectrical signal acquisition experiments.The main research work will be described in detail as follows:Firstly,for the polysomnography physiological signal monitoring system,in order to collect EEG signals with weak amplitude,relying on the EEG noise suppression technology,this paper focuses on the design of the analog front-end circuit and the right leg drive circuit,and analyzes the circuit’s operating characteristics and common To improve the characteristics of the mode rejection ratio;in order to accurately obtain the bio-impedance of the human body,based on the human bio-electric model,a simulation design was carried out,and a suitable excitation input and impedance detection scheme were given.In addition,from the perspective of power supply noise suppression and safety,low-noise power supply and interface security protection solutions are given.Secondly,in order to meet the multi-mode output requirements of the standard test signal output mode,common mode rejection ratio test mode and real bioelectrical signal playback mode of the signal source,the hardware and software design of the high-precision bioelectrical signal source is completed based on the direct digitalfrequency synthesis technology,human bioelectrical model and FPGA technology.Thirdly,the organic linkage sleep monitoring system and high-precision bioelectrical signal source complete the overall test and performance verification of the system.The test experiment is designed to ensure the high accuracy,stability and reliability of the output signal of the signal source.The performance parameters of the multi-channel sleep monitoring system are further verified by using the signal source as the test and evaluation platform.After the completion of the above test,the real multi-channel sleep monitoring experiment is carried out.Finally,after collating the test data and data processing analysis,compared with commercial products,the self-developed system has excellent features of high sampling accuracy(24bit),high sampling frequency(1kSPS),and better portability while meets the requirements of sleep acquisition(continuous monitoring for 10 hours).At the same time,it innovatively provide a high-precision bioelectric test evaluation platform,making the system more efficient and reliable in the bioelectric signal data collection process.