This paper introduces the current development and challenges of vision prosthesis.
Prosthesis Design ; Visual Prosthesis

This review paper presents the current research progress, challenges and future development on microelectrode array of retinal prosthesis, including epi-retinal and sub-retinal implants.
Microelectrodes ; Prosthesis Design ; Visual Prosthesis

OBJECTIVEEstablish the test platform of the intraocular lens loop, and the platform was evaluated through the experiment.

METHODSThe intraocular lens loop test platform is made up with three models. The different intraocular lens haptics support force can be completed by replacing different sample holder model.

RESULTSThe standard deviation and the coefficient of variation were calculated through the result of the fifteen samples. The standard deviation was 0.04 mN, and the coefficient of variation was 0.66%. The two values were in the acceptable range.

CONCLUSIONSThe platform was so stabilizing that it could be used to test support force of IOL loop. The different shapes of IOL could be tested on the platform through the replacement of the holder model.

In this paper, the present research status of artificial cervical disc is summarized according to its configuration, material selection and the methodologies of design. Finally, the further progress of research on artificial cervical disc is prospected as well.
Intervertebral Disc ; Joint Prosthesis ; Prosthesis Design

Based on the analysis of the influence of the valve pivot distance on the performance of mechanical heart valve (MHV), such as the valve opening and closing features, flow field characteristics and the valve assembly properties, value constraints of the valve pivot distance were established, and the reasonable valve was obtained by means of the finite element method. It can be shown that the central flow characteristics of the valve could be enhanced with the increasing of the ratio of pivot distance to valve inner diameter, but the plastic deformation of the ring could be liable to occur in the MHV assembly process. It is proved that the valve of specifications can be designed in similar ratio of pivot distance to valve inner diameter according to the result of the valve performance experiment.
Heart Valve Prosthesis ; Heart Valves ; Prosthesis Design

OBJECTIVETo compare the color character of VITA shade guide and the custom shade guide with metal substrate.

METHODSColor of 9 sites of 5 series of VITA shade guides and custom shade guides with metal substrate were measured by means of PR-650 spectrophotometer.

RESULTSThe color range of VITA shade guide were that L* was 56.86-73.86, a* was-1.29-3.69, b* was 7.09-21.94, and the transparence was 3.20-7.59. The color range of the custom shade guide was that L* was 60.59-78.54, a* was -1.09-4.99, b* was 7.60-22.35, and the transparence was 0.23-10.98. L*, a* and b* of the custom shade guide with metal substrate were higher than VITA shade guide, and the transparence was differet. The color difference of homonymy shade tab between custom shade guide and VITA shade guide was larger than 1.5 NBS.

CONCLUSIONThere is color difference between VITA shade guide and custom shade guide. Metal substrate has effects on the color of cero-metal prosthesis, and color selection in clinic should be carefully considered.

BACKGROUNDArtificial joints present certain problems such as osteal absorption and lysis induced by wear debris which leads to loosening of the prosthesis over a period of time. Here we propose a design of an artificial magnetic suspension joint that was prepared by integrating the medical theories of modern material science, magnetism, and medical physics.

METHODSAccording to clinical characteristic of biological and mechanical for hip joint, we designed the appearance and dimensions of magnetic suspension joint and placed neodymium-iron-boron permanent magnets in the prosthesis. As the same time, we performed mechanical and biological experiments using artificial magnetic suspension hip joints models.

RESULTSBy simulated the human hip structure and the external load, we discovered the artificial magnetic suspension hip joints models had much lesser amount and size of wear debris than the ceramic/ceramic artificial hip joint prosthesis in friction wear tests. The force between the artificial joints with magnetic materials that we have calculated is feasible for application of artificial joint. The design of artificial magnetic suspension hip joints models was plausible technically and safe biologically.

CONCLUSIONArtificial magnetic suspension hip joints may effectively reduce the incidence of the loosening of prosthesis over a period of time.

Based on the introduction of multi-agent and individual artificial hip joints, this paper reports a multi-agent design system for individual artificial hip joints. Three agents are defined, the first is to optimize the diameter of hip joint, the second for FEM, the third for simulation between the prosthesis and acetabulum cup. The paper lays emphasis on the second agent.
Acetabulum ; Hip Joint ; Hip Prosthesis ; Humans ; Prosthesis Design

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