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

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

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.

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

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

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

According to analyses of the real-time performance of the visual prosthesis image processing system, down-sampling is a key factor which influences the processing speed. Based on these analyses, the algorithm of grid sampled averaging was proposed for down-sampling. Then the effect of grid parameters on the result and algorithm complexity was evaluated by using the regional-averaging algorithm as a reference. Our research shows that the grid-averaging algorithm could reduce the computation burden by 90% or more, with no significant difference from the regional-averaging algorithm.
Algorithms ; Image Processing, Computer-Assisted ; methods ; Visual Prosthesis

Three-electrode testing method was used to investigate the effect of temperature on electrode impedance, and the pH shifts in saline solution resulting from the electrical stimulation were also determined. Experiments in PBS (phosphate buffered solution) solution showed that the electrode impedance was almost invariable at the human body temperature range (35 degrees C-40 degrees C). And the experiments in unbuffered saline solution showed that pH shifts decreased from 0.03 to 0.005 when the frequency of biphasic charged-balanced pulses increased from 1 Hz to 100 Hz. Even stimulated by monophasic pulses (frequency is 15 Hz, amplitude is 50 microA), the stimulus-induced pH shift of electrode only varies 0.15 (anodic pulse current increased 0.15 and cathodic pulse current decreased 0.15).
Electrochemistry ; Eye, Artificial ; Materials Testing ; Microelectrodes ; Prostheses and Implants