Boosting spatial resolution of visual prostheses is an effective method to improve implant subjects' visual perception. However, power consumption of visual implants greatly rises with the increasing number of implanted electrodes. In respond to this trend, visual prostheses need to develop high-efficiency wireless power transmission and high-speed data transmission. This paper presents a review of current research progress on wireless power and data transmission for visual prostheses, analyzes relative principles and requirement, and introduces design methods of power and data transmission.
Electric Power Supplies ; Prosthesis Design ; Visual Prosthesis ; Wireless Technology

The paper proposed a new method to design and fabricate a flexible neural microelectrode arrays (MEA) for retinal prosthesis, the ion-beam technology was introduced to decrease the width of conductive wires and the distances between wires, a high density MEA (120 microelectrodes with a matrix of 10 x 12) was fabricated on a single layer of polymer from this. The MEA was proved to possess a fine electrochemical property. In vitro test, the average impedance of MEA on 1 kHz was 16 k omega +/- 2 k omega and the average phase difference was -85 degrees +/-30 degrees.
Micro-Electrical-Mechanical Systems ; Microelectrodes ; Prosthesis Design ; Visual Prosthesis

Anxiety is usually generated because of the threatened feeling. The data of electrocardio, respiration, blood volume pulse and skin conductance signals were collected. The arithmetic of Relief were used for the feature selection and combined with k-Nearest Neighbor (kNN) arithmetic and Support Vector Machine (SVM) arithmetic for classification. The results show that the combination of Relief-SVM is better than combination of Relief-kNN on the recognition of anxiety state. The emotion recognition based on multi-physiological signals is superior to that based on one single signal.
Algorithms ; Anxiety ; Artificial Intelligence ; Humans ; Pattern Recognition, Automated ; Support Vector Machine

The frequency content of many biomedical signal s can change rapidly with time. Conventional Fourier spectral analysis techniques are insufficient for analyzing the time-varying spectral content of these signals. By mapping a one-dimensional function of time(or frequency), the time-frequency representation can localize the signal energy in both the time and frequ ency directions. It has been shown that many biomedical signal problems may benefit from time-frequency analysis. The basic method of time-frequency analys is and its application in biomedical signals processing are introduced.

Objective To assess the efficacy and feasibility of Wingspan stents for symptomatic atherosclerotic stenosis of the bas-ilar artery.Methods Clinical data of 40 patients with symptomatic atherosclerotic stenoses in the basilar artery were analyzed retro-spectively.The operative successful rate,the degree of stenosis,perioperative complications and the results of clinical and imaging follow-up were analyzed.Results The technical success rate was 95.35%.The rate of procedure-related complications during the perioperative period (30 days)was 20.0% (eight of 40 patients).There were two patients with no permanent neurological sequelae. Ipsilateral stroke or death occurred in six patients(1 5%).Thirty-six patients(92.3%)were available for a clinical follow up.The mean follow-up period was 36.3 months (range 12-75 months).Seventeen patients (47.2%)were available for follow-up imaging with DSA or CTA.The mean imaging follow-up period was 9.4 months (range 4-41 months).Symptomatic in-stent restenosis (ISR)was documented in two (1 1.76%)of these patients.Three ischemic events occurred during the follow-up period in 12 months.The adverse event rate was 8.33% at 1 year.Conclusion Wingspan stents for symptomatic atherosclerotic stenosis of the basilar artery was an effective and feasible technique,but we should carefully grasp the operation indications.

Visual prostheses have the potential to restore partial vision for the blinds. The stimulating electrodes generate reproducible phosphenes. Still limited by the low resolution vision used in visual prostheses nowadays, it is important to optimize the image processing strategies in order to deliver better visual information to the patients. This paper presents a review of the current research progress on the image processing strategies based on visual attention models under simulated prosthetic vision and related psychophysics.
Computer Simulation ; Image Processing, Computer-Assisted ; methods ; Visual Prosthesis

In this paper, we used the eletrotactile vision substitution system designed by ourselves to display Chinese characters on the 16x16 electrode array through some simple image processing algorithms and multiplexing technology. Based on this, simple Chinese character recognition experiment was conducted. The result of the experiment shows that the electrotactile vision substitution is a feasible solution for the blind to read simple Chinese characters and the result also solidifies the foundation of further study about more complex real-time image electrotactile display.
Algorithms ; Communication Aids for Disabled ; Image Processing, Computer-Assisted ; Language ; Touch ; Vision, Ocular

A wireless transmission system for visual prosthesis is introduced. Power and data are transmitted through inductive link between only one pair of coils, in order to reduce the size of the device. The transmitter is based on Class-E power amplifier due to its high efficiency, and a modulation circuit is added to control the dc supply of the Class-E amplifier to achieve ASK modulation of data with modulation depth of 25%. In addition, an experimental system is implemented, and test shows that it sufficiently supports a 16-channel micro-stimulator on power delivery and data transfer rate.
Amplifiers, Electronic ; Automatic Data Processing ; Electric Power Supplies ; Electronics, Medical ; Prosthesis Design ; Telemetry ; Visual Prosthesis

This paper introduces the current research progress on effect factors of mobility performance based on simulated prosthetic vision.
Phosphenes ; Prostheses and Implants ; Vision, Ocular

This paper employed a DSP platform to create the real-time and portable image processing system, and introduced a series of commonly used algorithms for visual prostheses. The results of performance evaluation revealed that this platform could afford image processing algorithms to be executed in real time.
Algorithms ; Image Processing, Computer-Assisted ; instrumentation ; methods ; Signal Processing, Computer-Assisted ; instrumentation ; Visual Prosthesis