the retinal prosthesis for the blindhealthit/slides/hit-kelly12.pdf · the retinal prosthesis an...
TRANSCRIPT
![Page 1: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/1.jpg)
The Retinal Prosthesis for the Blind
October, 2012
Shawn K. Kelly, PhD
VA Center for Innovative Visual Rehabilitation
Carnegie Mellon University
![Page 2: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/2.jpg)
The Retinal Prosthesis
An electronic implantable device to restore functional vision to patients with certain
forms of blindness, primarily retinal degenerative diseases.
The device works by stimulating nerves in the visual system based on an image from
an external camera.
![Page 3: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/3.jpg)
Anatomy of the Eye
![Page 4: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/4.jpg)
Anatomy of the Retina
Direction of Light
Inside/Front
Outside/Back
![Page 5: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/5.jpg)
Sending Images to the Brain
![Page 6: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/6.jpg)
Degenerative Diseasesof the Outer Retina
• Age-related Macular Degeneration (AMD)– Loss of photoreceptors in macula (center),
working outward
– Strikes at age 60-80 with increasing incidence– May take decades to go blind– 2 (?) million cases in US, tens of millions
worldwide
![Page 7: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/7.jpg)
Degenerative Diseasesof the Outer Retina
• Retinitis Pigmentosa (RP)– Loss of photoreceptors in periphery, working
inward
– Genetic, strikes at age 15-60– Typically a decade or less to go blind– 100,000 cases in US, 1.7M worldwide
![Page 8: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/8.jpg)
Living with RP
![Page 9: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/9.jpg)
The Boston Retinal Implant
• Electronic prosthesis to restore functional vision to patients with retinitis pigmentosa and age-related macular degeneration
• 20-year collaboration: MIT, MEEI, VA, Cornell, Carnegie Mellon, and others
![Page 10: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/10.jpg)
Subretinal Implant PlacementD
irection of Light
Inside/Front
Outside/Back
![Page 11: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/11.jpg)
Retinal Prosthesis Function• Electrically stimulates ganglion nerves based on an
external camera image
ImageProcessing
PowerAnd DataTransmission
![Page 12: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/12.jpg)
Other Visual Prostheses
Epiretinal Cortical
![Page 13: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/13.jpg)
Visual ProsthesisResearch Worldwide
Optic Nerve
Cortical
Retina Epi
Retina Sub
![Page 14: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/14.jpg)
Challenges
• Surgical– Place electrode array safely and securely– Place electronics where they won’t cause damage
• Microfabrication– Electrode materials that can safely deliver needed charge
but not physically damage tissue– Water-tight packaging of electronics
• Electrical Engineering– Deliver balanced electrical current to electrodes– Wirelessly deliver power and image data to implant
• Image Processing– Intelligently downsample camera images to 256 pixels– Convey saliency, maximum information about environment
![Page 15: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/15.jpg)
Short-term HumanProof-of-concept Trials
• 1998 – 2000, Surgical trials on six volunteers
• Epiretinal stimulation for a few hours
• Reported spots, lines, not complex shapes
Rizzo, et al. IOVS, 2003 Rizzo et al. IOVS, 2003
![Page 16: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/16.jpg)
Portable, 100-channelNeural Stimulator
![Page 17: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/17.jpg)
Short-term HumanProof-of-concept Trials
Video - surgery
![Page 18: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/18.jpg)
Short-term HumanProof-of-concept Trials
Video - clouds
![Page 19: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/19.jpg)
Short-term HumanProof-of-concept Trials
Video - spots
![Page 20: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/20.jpg)
What We Learned
• This concept works – patients can see spots and lines, distinguish from control
• We need to develop a chronic implant to allow patients to learn
• A number of new technologies needed to be developed for chronic
implantation
![Page 21: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/21.jpg)
Wireless Power and Data
Power and data are delivered by inductively coupled coils via magnetic fields
![Page 22: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/22.jpg)
Miniaturize:Integrated Circuit Design
Custom chip design is labor-intensive, but necessary given our size and power
restrictions
Kelly, et al. IEEE ISSCC, 2004 Theogarajan et al. IEEE ISSCC, 2006
Kelly, et al. IEEE TBioCAS, 2011 Theogarajan IEEE JSSC, 2008
![Page 23: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/23.jpg)
First-Generation Implant• Implanted in 3 minipigs for up to 10 months in
2008• Wireless power and data telemetry• Coated in silicone – viable for many months, not
decades
Shire, et al. IEEE TBME, 2009
![Page 24: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/24.jpg)
Improvements to First Generation Implant
• Hermetic barrier to protect circuits
• Larger telemetry coils
• Easier surgical access for electrode insertion
![Page 25: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/25.jpg)
Second Generation ImplantAb externo approach
• Electrode array enters the space under the retina through the scleral wall of the eye.
![Page 26: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/26.jpg)
Hermetic Titanium Case
• Ceramic 19-pin hermetic feedthrough
• Curved titanium case
• Laser-welded top and bottom lids
![Page 27: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/27.jpg)
Sputtered Iridium OxideFilm Electrodes
• Higher charge capacity• 1 to 6 mC/cm2
• Pt is limited to 100 µC/cm2
• But the Shannon Limit is still in effect!
![Page 28: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/28.jpg)
Prototype Implant
![Page 29: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/29.jpg)
In vivo Results
• Recorded artifact of current pulses from cornea – shows implant was working
• Waveform is measured at implant and telemetered out
• Noisy, but you can see the step-ramp components, and variation of voltage with current
Kelly, et al. IEEE ISABEL, 2009 Kelly, et al. IEEE TBME, 2011
Kelly, et al. IEEE EMBC, 2009 Kelly, et al. BSPC, 2011
![Page 30: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/30.jpg)
Third Generation Prosthesis• Hundreds of channels (>256)
• Smaller hermetic case
• Stimulator chip and electrode array under development
![Page 31: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/31.jpg)
Image Processing
![Page 32: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/32.jpg)
Future Research
• Finish 256+-channel retinal prosthesis, prepare for FDA clinical trials
• Design external camera system, portable telemetry system, etc.
• Image processing to convey maximum information with 256 pixels.
![Page 33: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/33.jpg)
The Boston RetinalImplant Project
Engineering• John L. Wyatt, PhD (MIT)• Douglas B. Shire, PhD (VA, Cornell)• Shawn K. Kelly, PhD (VA, CMU)• Ashwati Krishnan, MS (CMU)• Marcus Gingerich, PhD (VA, Cornell)• Attila Priplata, PhD (VA, MIT)• William Drohan, MS (VA, MIT)• Bruce McKay, BS (MEEI, Cornell)• Oscar Mendoza (MIT)• Carmen Scholz, PhD (Alabama)
• Stuart Cogan, PhD (EIC Biomedical)• William Ellersick, PhD (Analog Circuit Works)• Sonny Behan (Sonny Behan Consulting)
Medicine and Biology• Joseph F. Rizzo, MD (VA, MEEI)• Jinghua Chen, MD, PhD (MEEI)• Hank Kaplan, MD (Louisville)• Vasiliki Poulaki, MD (MEEI)• Shelley Fried, PhD (VA, MGH)• Ralph Jensen, PhD (VA)• Ofer Ziv, PhD (VA, MIT)• Lotfi Merabet, OD, PhD (VA)
Thanks to:Department of Veterans Affairs, MOSIS, NIH, NSF, DoD, Catalyst Foundation
![Page 34: The Retinal Prosthesis for the BlindHealthIT/slides/HIT-Kelly12.pdf · The Retinal Prosthesis An electronic implantable device to restore functional vision to patients with certain](https://reader035.vdocument.in/reader035/viewer/2022062413/5aa13fbd7f8b9ac67a8b8dca/html5/thumbnails/34.jpg)
Discussion