Wearable SEMG Detection Device For A Prosthetic Hand

Physically handicapped, particularly in upper limb disabled, brings a great deal of inconvenience for living, working and studying. The upper limb disabled people is huge amount in the country which got the biggest population such as ours particularly. With the development of science and technology, using the latest scientific and technological achievements to help the disabled recover or partially recover the quality of life of the normal population has been engaged in every field of biomedical research scientists' obligatory social responsibility.In this paper, based on surface electromyography recognition algorithm in its own research laboratories, facing myoelectric prosthetic hand, developed a surface EMG acquisition wearable device independently. Mainly for the following work:The mechanism of surface EMG signals were analyzed from the perspective of physiology and anatomy. And use multi-channel physiological signal recorder to capture standard surface EMG signals from amplitude, frequency characteristics analyzing to determine the main technical indicators EMG detection circuit design.Starting from the passive electrode sensor, design experiments to detect both wet and dry electrodes, two electrodes were used to detect its characteristic impedance: wet electrode impedance change is small, less resistance to the capacitive-based, impedance versus frequency liters high decreases; dry electrode impedance changes in the larger, the larger the resistance, but also for the capacitive impedance versus frequency characteristics and the same wet electrode. Design experiments to detect both wet and dry electrodes are coupled to the body for the impedance characteristics. Wet electrode coupling impedance characteristics change more stable performance, the impedance decreases with increasing frequency; dry electrode impedance characteristics showed stable coupling requires a longer time, a large resistance value, both expressed as capacitive coupling.Abounding active EMG detection circuit electrode, the active electrode design containing a frequency notch filter circuit, which realizes the circuit surface EMG signal amplification, signal conditioning functions. Test the amplitude-frequency characteristics of the circuit, CMRR and input resistance characteristics and the actual acquisition surface EMG. Design of the control group sEMG comparative experiments, select the time domain and frequency domain value, to make a functional assessment of the circuit arrangement that the circuit arrangement can be more effectively detect surface EMG, time domain characteristic value trend indicators and control signals are closer, but also found that the circuit arrangement there is a difference of anti-baseline shift performance shortcomings.The disadvantage for the design of a baseline based on the elimination of the sub tractor circuit to suppress baseline drift. Measuring its amplitude-frequency characteristics, CMRR and input resistance. Functional design experiments proved that the actual surface EMG acquisition process, this circuit arrangement can be a long time stable acquisition surface EMG different force levels under control can be used to provide a source signal EMG prosthetic hand. Finally, to achieve a wearable EMG signal acquisition device related hardware circuit design to achieve the normal operation of the processor, the analog signal processing, and computer communication function lower.Then, in accordance with the rules and wearable electrode device with the relevant requirements of the entire apparatus of the shell structure design, and the use of 3D printing technology to design and manufacture it. On the whole the dimensions and weight of the implementation of the measure, the actual effect of the demonstration dressed.Finally, for all the work, it carried out summary of useful experience and problems in the development process faithfully. Carried out the future direction of the work instructions.