ABSTRACT
Research on how to totally or partially restore the vision has attracted more attention in the fields of neural engineering and tissue engineering. Neural interface and visual prosthesis offer alternative ways for partially repairing the visual impairment. The most widely used visual prosthetics are based on retinal stimulation. This article is a state-of-art review of the principles, technical details and the limitations of retinal prosthesis.
Subject(s)
Humans , Blindness , Therapeutics , Electric Stimulation , Electrodes, Implanted , Prosthesis Design , Methods , Retina , Physiology , Visual Perception , PhysiologyABSTRACT
Cortical visual prosthesis, optic nerve visual prosthesis and vision substitution devices are alternative ways for repairing the visual impairment in case of optic nerve injury, retina lose or blindness without fully developed central visual system. This article is a state-of-art review of the principles, technical details and the limitations of different types of prostheses beyond the retinal prosthesis.
Subject(s)
Animals , Humans , Artificial Intelligence , Electric Stimulation Therapy , Methods , Optic Nerve , Prosthesis Design , Prosthesis Implantation , Methods , Retinal Ganglion Cells , Physiology , Vision Disorders , Rehabilitation , Visual Cortex , Visual PathwaysABSTRACT
Retinal model is an essential part in the retinal prosthesis. Based on the retinal physiology and the experimental data, the model is able to simulate the information processing in the retina, and can be used to investigate the relation between the input image and the neuron firing. We can categorize the models into circuit realization and algorithm realization. This article is a state-of-art review of different types of retinal models.
Subject(s)
Humans , Algorithms , Models, Biological , Models, Neurological , Neural Networks, Computer , Prostheses and Implants , Retina , PhysiologyABSTRACT
Heart rate variability (HRV) is the tiny variability existing in the cycles of the heart beats, which reflects the corresponding balance between sympathetic and vagus nerves. Since the nonlinear characteristic of HRV is confirmed, the Recurrence Plot method, a nonlinear dynamic analysis method based on the complexity, could be used to analyze HRV. The results showed the recurrence plot structures and some quantitative indices (L-Mean, L-Entr) during asphyxia insult vary significantly as compared to those in normal conditions, which offer a new method to monitor brain asphyxia injury.
Subject(s)
Animals , Male , Rats , Algorithms , Autonomic Nervous System , Electrocardiography , Methods , Heart Rate , Physiology , Hypoxia-Ischemia, Brain , Nonlinear Dynamics , Rats, Wistar , Signal Processing, Computer-AssistedABSTRACT
Due to its great clinical significance, brain injury following cardiac arrest (CA) has attracted more attention now. Meanwhile, there are currently no approved real time objective methods used to monitor brain injury following CA. In this study, we adopt the method of nonextensive Kullback-Leibler Entropy in investigating the HRV signals from brain injury and compare the result with that of corresponding EEG analysis. The comparative analysis shows that Kullback-Leibler Entropy can reveal the injury level of brain following CA. And we propose a novel quantitative approach for monitoring brain injury.