A Research On Key Techniques Of Brain-computer Interface To Induce Artificial Vision

With the rapid development of integrated optics,microring resonators,as an important functional component of photonic integrated circuits,have been widely used in various fields.In recent years,the invention of optical biosensor has invoked a very rapid development in the field of brain computer interface.In research,efforts are being paid to achieve highly sensitive brain-computer interface using photoelectric sensing technology.Then,based on the echo wall resonant mode principle of microring resonator,high-sensitive optical biosensors may be built.Through the research of artificial visual prosthesis,the key components of implantable brain-computer interface of optic nerve prosthesis and electro-optic modulator based on microring resonator of silicon-on-insulator are designed and prepared to provide help for the treatment of visual disorders and other related diseases and promote the development of clinical medical technology.Meanwhile,the basic structure and resonant characteristic mechanism of the microring resonator,and the effect of the carrier concentration on the effective refractive index of silicon in the plasma dispersion effect,are both described and analyzed.The theoretical modelling of the microring resonator electro-optical modulator was carried out systematically via formuladerivation,and the optimum size of the ridge waveguide structure of the electro-optical modulator was obtained.In order to match the size of optic nerve,simulation software was used to determine the specific parameters of the microring array.Then,the design chart of the overall chip was drawn out,and the flow plate was completed.The overall chip was taken to be 3mm*2.7mm in size,with a 4×4microring resonator electro-optic modulator integrated on it.When the optical wavelength is 1.55μm,the overall loss of the microring resonator is about 27.7d B,and the free spectral range is about 9.75nm,so the Q factor is about 1.3×10~5.After that,the basic performance test of the chip and in vivo experiment were carried out to verify the feasibility of the microring array as a brain computer interface,and to confirm the rationality of the structure design and the correctness of the processing and preparation process.The optical array brain-computer interface designed in this work realizes the"read"function,and the brain-computer interface constructed with all-optical network provides a new solution for visual prosthesis.The electro-optical effect is used to load electrophysiological signals into optical signals,greatly improve the spatial resolution of nerve detection,reduce the difficulty of data acquisition and processing,and solve the crosstalk and wire layout problems caused by traditional electrodes.