Retinitis pigmentosa (RP) and age-related macular degeneration (AMD) are two predominant causes of visual deterioration. Retinal prosthesis embeds a micro-electric chip or a micro-photoelectric diode array in the sub-retina or epi-retina, which is used to stimulate the remainder of inner retina, so as to restore some degree of sight. Retinal prosthesis has attracted most attention in the field of artificial visual function recovery, and along with deep-going research, many issues need to be resolved. In this paper, the theory of retinal prosthesis and the status quo of research in many countries are introduced, the key issues which influence the application of the retinal prosthesis are discussed in detail, and some notions and advices are presented.
Electric Stimulation Therapy ; instrumentation ; methods ; Humans ; Macular Degeneration ; surgery ; Photic Stimulation ; instrumentation ; methods ; Prosthesis Design ; Retinitis Pigmentosa ; surgery ; Visual Prosthesis ; standards ; trends

The application of artificial retina was introduced. The principal characteristics of artificial retina material were reviewed in particular. Moreover, the recent research development and application prospect were discussed.
Animals ; Bioartificial Organs ; trends ; Humans ; Prosthesis Design ; Retina ; Tissue Engineering ; methods

Subretinal prosthesis is one kind of retinal prosthesis, which means that a microimplant based on MEMS technology is inserted in the subretinal space to stimulate the optic nerve and elicit an electrical-evoked response on the cortical region. The subretinal implant is made up of extraocular part and intraocular part. As an important part, the latter consists of accessorial setting and stimulation chip that contains microphotodiode array (MPDA) and microelectrodes. The paper main body is made up of four parts. Firstly significance of the retinal prosthesis is given out; secondly fundamentals on both in retina physiology and retinal prosthesis theory are introduced simply. Then the key segment about the subretinal microimplant is presented in detail. In the third segment, first of all is its design concept, the second is fabrication of MPDA which consists of several parts. First is microscopic configuration, electric prototype schematic and chip image CMOS. The second is detailed fabrication flow with several special materials. Then is situation of its dimension. The fourth segment presents challenge and outlook.
Artificial Organs ; Electric Stimulation Therapy ; instrumentation ; Electrodes, Implanted ; Evoked Potentials, Visual ; physiology ; Humans ; Microelectrodes ; Prosthesis Implantation ; methods ; Retina ; physiology ; surgery ; Visual Perception ; physiology

Surface myoelectric signal analysis has proved effective for assessing the electrical manifestations of localized muscle fatigue. In the past, the analysis of muscle fatigue was restricted to isometric, constant force contractions due to the limitation of signal processing technique. The development and recent availability of spectral estimation techniques specifically designed for nonstationary signal analysis have made it possible to extend the employment of muscle fatigue assessment to dynamic contractions, thus opening new application fields such as ergonomics rehabilitation and sports medicine. This paper reviews the current study achievements of using surface myoelectric signals in muscle fatigue assessment, particularly in that during dynamic contractions. The conclusions provide theoretical bases for encouraging further studies on the mechanisms of muscle fatigue.
Electromyography ; methods ; Humans ; Muscle Fatigue ; physiology ; Muscle, Skeletal ; physiology ; Signal Processing, Computer-Assisted

The energy supply for the stimulation arrays is the key component in retinal implants. Usually, the thin film solar cell is used to supply energy, but it can not supply enough stimulation power. One of the general idea of incident energy supply is radio frequency (RF) circuit. Another method is to convert near infrared (NIR) radiation and enable retina cell stimulation. In this paper, firstly, we aim at listing these two energy supply methods, and introduce the characteristics of RF circuit and NIR conversion method. Especially, we present the design procedure in detail. The next part is a discussion on the advantage and disadvantage of adopting these two methods. At last, we explicate the new research and application of the energy supply for the use as retinal implants, and we envisage the future.
Animals ; Blindness ; rehabilitation ; Electric Power Supplies ; Electric Stimulation ; instrumentation ; methods ; Electrodes, Implanted ; Evoked Potentials, Visual ; physiology ; Humans ; Prosthesis Design ; Prosthesis Implantation ; methods ; Retina ; physiology

Objective To induce an NLRP3-/- mouse model of ulcerative colitis(UC)using different concentrations of dextran sulfate sodium(DSS)and different administration times,and to analyze and evaluate the advantages and disadvantages of the preparations to provide a more suitable animal model for the study of UC pathogenesis in humans and the development of therapeutic drugs.Methods Forty-eight male NLRP3-/- specific-pathogen-free mice were divided randomly into blank,2.5％7 d,3％7 d,and 3％5 d groups(n=12 mice per group).UC mouse models were induced using combinations of different concentrations and administration times of DSS.Body weight,DAI(disease activity index)score,hematoxylin and eosin(HE)staining,colon length,and related indicators(interleukin IL-6,tumor necrosis factor(TNF)-α,and tight junction protein(ZO-1))were observed and evaluated.Results(1)UC membrane type was induced in each group with different concentrations and administration times.(2)Mouse body weight decreased,the fecal occult blood became more positive,the DAI score increased,and more mice died with increasing DSS concentration and administration time.(3)Longer administration time and higher concentration of DSS were also associated with more severe damage to the intestinal mucosa,as shown by HE staining.(4)Immunohistochemistry showed that the inflammatory factors TNF-α and IL-6 were increased in the model group compared with the blank control group,while expression of ZO-1 was decreased compared with the blank group.Conclusions(1)Administration of 2.5％or 3％DSS for 7 days or 3％DSS for 5 days can induce UC in NLRP3-/- mice.(2)The combination of DAI score,HE staining,the detection of related indicators,and mouse survival rate indicated that NLRP3-/- mice treated with 3％DSS for 5 days produced the most suitable UC model to study the clinical manifestations and drug treatment of UC.

The power and signal transmission technology is one of the key technologies in neuroprosthetic research. This paper proposes firstly the related theory of power and signal transmission technology in neuroprosthetic, then summarizes the three key aspects of the power and signal transmission technology in neuroprosthetic. After analyzed the development of the inductive wireless power harvesting technology, the wireless telemetry technology and the wireless power harvesting telemetry technology, the emphasis on research contents will be proposed and discussed, which will help accelerate the further research of prosthetic.
Electric Power Supplies ; Electrodes, Implanted ; Humans ; Neural Prostheses ; Prosthesis Design ; instrumentation ; Signal Processing, Computer-Assisted ; instrumentation ; Telemetry ; instrumentation ; Wireless Technology ; instrumentation