The History Of The Bionic Eye

The History Of The Bionic heart and soulHere, we present a verbal description of a pile scheme, specific features of design and results of testing for a warning of a bionic nitty-gritty, types of them and its applications. The bionic snapper is intended to provide view, partly to the ocularly im meeted by use of the modern day electronics doodads want CCD cameras. The comprises a computer deterrent that sits in the tail end of the separates eye, linked up to a mini flick camera built into glasses that they wear. Images captured by the camera argon carryed to the chip off, which translates them into impulses that the brain can interpret. Although the images produced by the artificial eye were far from perfect, they could be clear enough to allow somewhatone who is other than dim to recognise faces. The paper discusses the differences rangeing methodologies used in from individually one of them. During the tests and the clinical trails, this art made six blind pe ople to encounter their vision partially. The potential advantage of using bionic eye is to be able to remove the blindness completely by fashioning the advances in the present research and improving manufacturing technologies. This break done is likely to value approximately one crore man population who suffer from the most familiar casings of blindness, Retinitis Pigmentosa, Macular Degeneration. The implant bypasses the dis tranquillised cells in the retina and establishs the remain practicable cells. This is a basal piece of technology and really has the potential to shift peoples lives. But we pack to be aw be it is still some way in the future. understructureA Bionic Eye is a device, which acts as an artificial eye. It is a broad term for the entire electronics corpse consisting of the image sensors, processors, radio transmitters receivers, and the retinene chip. Based on the institute developed these devices argondeveloped only with minor to major differenc es, of these the devices with functional capability and those which ar clinically tried and results proved are discussed here. Here the designers objective is to go for a system that is technically perfect with no loop holes and that is harmless to the human corpse which receives the system and that is commercially viable both in terms of ease of manufacture, cost and the process of implanting.Blindness means loss of vision. Rods and Cones, millions of them are in the back of of all timey healthy human eye. They are biological solar cells in the retina that convert alight to electrical impulses impulses that travel along the eye nerve to the brain where images are formed. Without them, eyes lose the capacity to fit, and are declared blind. Degenerative retinal diseases result in death of photoreceptorsrod-shaped cells at the retinas periphery responsible for night vision and cone-shaped cells at its substanceresponsible for color vision. Worldwide, 1.5 million people suffer from retinitis pigmentosa (RP), the leading cause of inherited blindness. In the Western world, agerelated macular degeneration (AMD) is the major cause of vision loss in people oer age 65, and the issue is fair more critical as the population ages. Each year, 700,000 people are diagnosed with AMD, with 10 percent becoming legally blind, defined by 20/400 vision. Many AMD patients retain some degree of peripheral vision.Currently, at that place is no effective treatment for most patients with AMD and RP, the researchers say . However, if one could bypass the photoreceptors and directly stimulate the inner retina with visual symbols, one might be able to restore some degree of sight.Need for the BIONIC center of attentionIt has been shown that electric stimulation of retinal neurons can produce perception of light in patients suffering from retinal degeneration. Using this property the eye and annoy uses of the functional cells to retain the vision with the abet of electronicd evices that assist this cells in performing the task of vision, we can make these lakhs of people get back their vision at least artially. A design of an optoelectronic retinal prosthesis system that can stimulate the retina with resolution corresponding to a visual sharpness of 20/80-sharp enough to orient yourself toward objects, recognize faces, read man-size fonts, watch TV and, perhaps most important, lead an independent life. The researchers commit their device may someday bring artificial vision to those blind due toretinal degeneration.BIONIC EYE DEFINEDBionic Eye, Bio electronic eye, is a device that can provide sight the detection of light. It replaces the functionality of a part or whole of eye. it is used to replace functionality as nearly as add functionality. It is a complex combination of multiple devices which work together for restoration of the vision of the subject.The Diseases that cause blindness Retinitis Pigmentosa Macular DegenerationOf these, retinitis pigmentosa is a disease, which is a hereditary genetic disease in which peripheral rods discharge gradually progresses towards center of eye and results in tunnel vision.As for macular degeneration, it is likewise genetically related , it degenerates cones in macula region, causing damage to exchange vision moreover spares peripheral retina.MIT- HARVARD DEVICEThis device follows an Epi-Retinal Approach. In this Microelectrode stray replaces damaged photoreceptors, which act in the place of rods and cones to send the signals to ocular nerve. The origin source Laser(820nm wavelength). For image erudition it uses a CCD Camera. Patient spectacle holds the camera and index source.It consists of two systems, system-1 which senses and transmits image and power and other system which stimulates the cells, at that place by making brain visualize the image.System 1 CCD camera insert External light intensity CCD output amplitude-modulates laser source This hits photodiode start o f implant This in turn powers stimulator chip (SC)System 2 SC drives current to electrodes facing retina This excites the ganglionic cells axons optic nerve visual cerebral mantle in occipital lobe of brain Brain helps in perceiving an imageAdvantages Very other(a) in the visual pathway No Batteries imbed within clay No complicated surgical procedure Power Requirement of milliwattDisadvantages Axons b/w electrodes and ganglionic cells Other axons get excited unwanted perception of whacking blur Extra circuitry required for downstream electrical input mushy Retina Prosthesis using ASR ( schmalzy Silicon Retina)ASR is a solid state biocompatible chip which contains an array of photo receptors, and is implanted to replace the functionality of the defective photoreceptors .Current generated by the device in chemical reaction to lightstimulation will alter the membrane potential of the overlying neurons and thereby activate Visual ensationsthoerv iPsuhaolsspyhsetenmes. can b e evoked by electrical stimulation of the different levels of the visual pathway. Phosphenes are evoked by the stimulation of the eyeball or the visual cortex. Artificial vision created by the insureled electric stimulation of the retina has color. Epiretinal Approach involves a semiconducting material based device positioned on the cake of the retina to try to simulate the remaining overlying cells Sfutbhreerteintianla A pproach involves implanting the ASR chip behind the retina to simulate the remaining viable cells. implant DESIGNPrimitive devicesSingle photosensitive pixel(3mm in diam) modern devicesThe current micro photodiode array (MPA) is comprised of a regular array of individual hotodiode subunits, each approximately 20-20-m square and separated by 10-m lane stops (37). The resulting micro photodiode density is approximately 1,100/m2.IMPLANT featuresThe size of implant is 50um. And it needs no external power supply. The response 500nm to 1100nm wavelength response.Wor kingFor the technique to work, the patient must still form some functioning ganglion cells nerve cells that transmit visual information from the retinal cells to the optic nerve as well as a fully-functioning optic nerve. A flyspeck electronic pad is rigid onto the retina of one eye, so that the electrodes are in direct contact with the ganglion cells. Each of the devices 100 electrodes can stimulate 20 to 30 cells.Real-time visionThe user wears a pair of glasses that contain a miniature camera and that wirelessly transmits video to a cellphone-sized computer in the wearers pocket. This computer processes the image information and wirelessly transmits it to a tiny electronic receiver implanted in the wearers head.When received in the implanted chip, the digital information is transformed into electrical impulses sent into the ganglion cells. From there, the brain takes over as the information travels down the optic nerve to the visual cortex at the back of the brain. The whole process occurs extremely rapidly, so that patients see in real-time. This is important any noticeable lag could stimulate the vestibular-ocular reflex, making people feel dizzy and sick.Currently recipients of the device experience a relatively narrow view, but more electrodes should provide a greater field of vision. By stimulating more ganglion cells, he hopes that visual acuity will increase dramatically. His teams next goal is to design a device with 1000 electrodes.MANUFACTURING PROCESSImplants are comprised of a doped and ion-implanted silicon substratum disk to produce a PiN (positive- ingrained-negative) junction. Fabrication begins with a 7.6-cm diameter semiconductor grade N-type silicon wafer.For the MPA device, a photomask is used to ion-implant shallow P+ doped rise into the front surface of the wafer, separated by channel stops in a pattern of individual micro photodiodes. An intrinsic work automatically forms at the boundary between the P+-doped wells and the N-type substrate of the wafer. The back of the wafer is then ion-implanted to produce a N+ surface. Thereafter, an insulating mould of silicon nitrate is deposited on the front of the wafer, covering the entire surface except for the well openings. A thin adhesion layer, of chromium or titanium, is then deposited over the P+ and N+ layers. A transparent electrode layer of gold, iridium/iridium oxide, or platinum, is deposited on the front well side, and on the background side. In its simplest form, the photodiode and electrode layers are the same size. However, increasing the photodiode collector to electrode flying field ratio can increase the current density available at each individual micro photodiode subunit. Post Implant function and Inference. step procedure IR stimulation at 940nm on the ASR chip enter at the corneal surface using contact lens electrode comparison of responses of gold, platinum and iridium electrodes Iridium based device has a seven-day persistence Stability of these electrodesBIO-COMPATIBILTY RESULTSThere is no progressive change in retinal appearance that may be associated with retinal toxicity. But there is loss of photoreceptive layer over the region of implant, which is expected due to deprival of oxygen and nutrients to those cells underlying the chip.Multiple Unit Artificial Retina Chipset (MARC)The other revolutionary bio electronic eye is the MARC , this uses a ccd camera input and a laser beam or rf to transmit the image into the chip present in the retina using this a resolution of 100 pixels is achieved by using a 1010 array. It consists of a platinum or rubber silicon electrode array placed inside the eye to stimulate the cells.THE MARC SYSTEM BLOCKOutside EyeThe video input to the marc system block is given through a CCD camera. This image is further processed using a PDA sized image processor to transmit it , we do pulse width flexion in first stage and then ASK modulation is done.This signal is further amplified using a class E power amplifier and contractable using RF telemetry coils.Inside EyeThe signal received from the RF telemetry coils is power recovered and then these signal is ASK demodulated and the data and measure is recovered from this signals and these signal are sent to the configuration and control block of the chip which from its input decode what information has to be sent to each of the electrodes and sends them this data. And the electrodes in turn stimulate the cells in the eye so as to send this stimulation to the brain through optic nerve and help brain in visualizing the image and while this process is going on the status of each electrode is sent to the marc diagnostics chip outside the eyeBlock Diagram Of Image Acquisition SystemThe image acquisition system consists of a CMOS digital camera which acquires images and sends it to the Analog to Digital Converter. It converts this parallel of latitude input to digital data. This data is first sent into a video buffer wher e it is processed, the images are color mapped and this processed images are sent through RS232 interface. this serial data is then sent to the electrodes or testing observe through a RF circuit or laser beam.Marc hermetic Sealing And PositioningThe RF coils either intra ocular or surplus ocular coil arrangement as shown in figure. This rf probes receives the genetic RF energy and give it to the MARC chip. The AC wires from this coil is sent to the MARC chip. This chip is hermetically sealed in silicone gel and the other sides of the chips have the electrodes, which stimulate the cells in eye.Advantage of the Marc system Compact Size 66 mm Diagnostic Capability Reduction of stress upon retinaConclusionResearchers throughout the world have looked for ways to improve peoples lives with artificial, bionic devices. Its been 40 days since Arne Larsson received the first fully implanted cardiac pacemaker. Researchers throughout the world have looked for ways to improve peoples lives with artificial, bionic devices. Bionic devices are being developed to do more than replace defective parts. Researchers are in addition using them to fight illnesses.Providing power to run bionic implants and making connections to the brains control system pose the two great challenges for biomedical engineering. But what ever be the pro and cons of this system. If this system is fully developed it will change the lives of millions of people around the world. We may not restore the vision fully, but we can help them to least be able to find their way, recognize faces, read books, above all lead an independent life.