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CAN BLIND PEOPLE SEE AGAIN?

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THE HUMAN EYE

Velez Guerra

The retina is a thin layer of tissue that lines the back of the eye on the inside. It is located near the optic nerve. The purpose of the retina is to receive light that the lens has focused, convert the light into neural signals, and send these signals on to the brain for visual recognition.

Velez Guerra

The retina processes light through a layer of photoreceptor cells. These are essentially light-sensitive cells, responsible for detecting qualities such as color and light-intensity. The retina processes the information gathered by the photoreceptor cells and sends this information to the brain via the optic nerve. Basically, the retina processes a picture from the focused light, and the brain is left to decide what the picture is.

Velez Guerra

Due to the retina's vital role in vision, damage to it can cause permanent blindness. Conditions such as retinal detachment, where the retina is abnormally detached from its usual position, can prevent the retina from receiving or processing light. This prevents the brain from receiving this information, thus leading to blindness.

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RETINAL DISEASESNORMAL VISION

RETINITIS PIGMENTOSA

• HEREDITTARY• PROGRESSIVE• RARE

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AGE-RELATED MACULAR DEGENERATION

RETINAL DISEASES

• AGING• COMMON

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RETINAL PROSTHESIS

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TYPES OF SYSTEMS

Argus II

Alpha IMS

James D. Weiland, Senior Member, IEEE, and Mark S. Humayun, Fellow, IEEE

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Argus II

bionic-eye-17-638.jpg?cb=1379656077

http://www.slideshare.net/rimjhimroy/bionic-eye-26377718

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Argus II

The Detection of Motion by Blind Subjects With the Epiretinal 60-Electrode (Argus II) Retinal Prosthesis

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Alpha IMS

Object Camera Implant+

Photo Receiver

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Alpha IMS

Chip is composed of:

Photo-receives Stimulating array

“Photo-Diode”

Blog | NeuroTechZone

http://www.google.nl/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAUQjhxqFQoTCNqFqc_60MgCFQS8cgodwvEFkA&url=http://neurotechzone.com/blog&psig=AFQjCNE8M_A1_RyoD95C4eszML00nJV5MQ&ust=1445426203576458

http://www.google.nl/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAUQjhxqFQoTCNqFqc_60MgCFQS8cgodwvEFkA&url=http://neurotechzone.com/blog&psig=AFQjCNE8M_A1_RyoD95C4eszML00nJV5MQ&ust=1445426203576458

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Alpha IMSA state-of-the-art retinal implant and its controller/battery

www.extremetech.comThe Bionic Eye,The Scientist Magazine

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ENGINEERING CHALLENGES

IMAGE PROCESSING

MICROELECTRONICS

ELECTRODES

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IMAGE PROCESSING SYSTEM

BASIC REQUIREMENTS

• Zoom• Brightness and contrast adjustment• Portability• Real-time operation• Decimation and enhancement

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MICROELECTRONIC CHIP

SIZE: small or large ?

Affected by the necessary

PACKAGING

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STIMULATING ELECTRODES

ARRAY DESIGN• 600 – 1000 electrodes required• Maximum electrodes density• 100nC impulses

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CONCLUSION• Retinal diseases lead to blindness

• Retinal prostheses restore the perception of light

• Two different examples: Argus II and Alpha IMS

• Analysis of technological issues

GOAL

PIXELIZED VISION

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THANK YOU FOR YOUR ATTENTION

REFERENCES1. Weiland, J., Liu, W. & Humayun, M. Retinal prosthesis. Annu. Rev. Biomed. Eng. 7, 361–401

(2005). 2. Weiland, J. Retinal prosthesis. Biomed. Eng.-61, 1412–1424 (2014). 3. Weiland, J., Cho, A. & Humayun, M. Retinal prostheses: current clinical results and future

needs. Ophthalmology 118, 2227–2237 (2011). 4. Weiland, J. & Humayun, M. A biomimetic retinal stimulating array. Eng. in Med. and Bio.

Magazine, IEEE 24, 14–21 (2005).

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Documents

retinal prosthesis

retinal detachment

retina processes light

processing light

blindness retinal prostheses

focused light

perception of light

lightsensitive cells