Optobionics

Optobionics

ABSTARCT:

MEMS (Micro Electro Mechanical Systems) technology has been attracting increasing attention in several medical fields for its possible applications in curing diseases, which were considered intractable until few years ago. A typical application, as example, regards the MEMS based cochlear implant, which is meant to give hearing to deaf people through a wireless communication device. Moreover, MEMS accelerometers are widely applied to detect movement, heat flow, skin temperature, heart rate, etc…Among all these applications, one in particular attracts the attention of researchers: the microchip retinal implant. Extended studies have been conducted in several places of the world in order to develop a microchip able to stimulate damaged retinal cells. This is very important for patients affected by Retinitis Pigmentosa (RP) and Age related Macular Degeneration (AMD).
The focus will be in particular on the function of the retina on the process of sight and the characteristics of the macula, the part of the retina, which gives the highest resolution for the images. The possible diseases and abnormal retinal conditions especially the aforementioned Retinitis Pigmentosa and Age related Macular Degeneration. In the second part of the project, the possible approaches to cure the retinal degeneration will be analyzed (i.e.: epiretinal and subretinal implant). In particular the study will focus on the micro devices applied in both the aforementioned approaches. On one side the epiretinal system is based on a retina encoder, a telemetry link and a stimulator device. On the other side the sub retinal implant is based on a silicon microchip of 2mm diameter, which contains microscopic solar cells called micro photodiodes.
The above design will convert the light energy from images into electrochemical impulses that stimulate the remaining functional cells of the retina in patients with AMD and RP. It is to produce visual signals similar to those produced by the photoreceptor layer in order to subsequently induce biological signals in the remaining functional retinal cells. The research will point the micro fabrication of these microchips and the possible alternatives in the process. Also the testing showed that animal models with the retinal implant responded to light stimuli with electrical Signals and sometimes brain wave signals. The induction of these biological signals indicated that visual responses had occurred.