06-01-2015, 04:23 PM
04-04-2017, 02:52 PM
Artificial retinas have been wished to regain the sense of sight for the visually impaired. Recently, artificial retinas with external chambers, stimulus electrodes and large-scale three-dimensional integrations (LSIs) have been actively developed for patients with retinitis pigmentosa and age-related muscle degeneration. Thus, in this seminar, we will discuss the possibilities of the artificial retina with thin-film transistors (TFT), which can be made in transparent and flexible substrates. Electronic photo devices and circuits are integrated into the artificial retina, which is implanted into the inner surface of the living retina in the back of the human eyeballs. In addition, the wireless power supply is used to drive the object. This helps to eliminate the connection cables and to realize complete artificial internal organs to improve the quality of life.
Artificial retinas have been ardently desired to regain the sense of sight for the visually impaired. Here electronic devices and photographic circuits replace the deteriorated photoreceptor cells. An artificial retina that uses thin-film transistors powered by a wireless power source. It has been found that the illumination profile can be correctly detected as the output voltage profile even if it is operated using unstable power source generated by inductive coupling, diode bridge and Zener diodes. This means the feasibility of implanting the artificial retina into human eyeballs.
In this Seminar we will be discussing about the Artificial Retina made with Fine Film Transistors, which can be made on transparent and flexible substrates. Electronic photo devices and circuits are integrated into the artificial retina, which is implanted into the inner surface of the living retina in the back of the human eyeballs. As the irradiated light proceeds from one side of the artificial retina and the stimulus signal exits from the other side, the transparent substrate is preferable. In addition, since human eyeballs are curved, the exible substrate is also preferable.
It is possible to make the spherical shape by designing a petal-like pattern. As a result, the artificial retina using TFTs are suitable for the epiretinal implant in the curved human eyeballs. The artificial retina using TFTs is manufactured using annealing. However, the power supply with cable harms the quality of life of people with visual impairment due to the annoying connection cables between the artificial retina and external equipment. Therefore, the wireless power supply is required to remove the connection cables and to perform the complete internal artificial organs to improve the quality of life.
Prosthetics of the retina
Blindness is one of the most devastating consequences of the disease. We developed the electronic artificial retina for the restoration of sight to patients suffering from degenerative retinal diseases such as Retinitis Pigmentosa and Age-Related Muscular Degeneration. In these conditions the photoreceptor cells degenerate slowly, leading to blindness. However, many of the internal neurons of the retina that transmit signals from the photoreceptors to the brain are largely preserved over an extended period of time. Foerster was the first to discover that electrical stimulation of the occipital cortex could be used to create visual perceptions, the phosphenes. Implantable microelectronic retinal prostheses represent a promising means of restoring sight to the blind. The conventional model of such devices includes an externally worn digital camera which samples the user's visual environment. This stream of visual information is then processed before being transported wirelessly to an implanted neurostimulator connected to a series of electrodes placed within or adjacent to the retina. Electrical stimuli are thus delivered to the surviving neurons of the retina to effect the perception of the phosphenes.