Advances in Bionic Eye Research Nigel Lovell and Gregg Suaning · Advances in Bionic Eye Research...
Transcript of Advances in Bionic Eye Research Nigel Lovell and Gregg Suaning · Advances in Bionic Eye Research...
Advances in Bionic Eye Research
Nigel Lovell and Gregg Suaning Graduate School of Biomedical Engineering
University of New South Wales, Sydney
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Biomaterials and tissue engineering
Bionics, biomonitoring and biomodelling
15 Academic and research staff
20 General staff
~50 PhD students + 10 others in Elec Eng
~60 P/G coursework students
~350 BE/MBiomedE students
~> $6 million research income p.a.
GSBmE
Biomonitoring and Bionics
Implantable sensors and devices (bionic eye, heart assist devices)
Wearable sensors for falls detection/prevention (triaxial accelerometer)
Clinical measurements for management of chronic disease (home telehealth)
Unobtrusive monitoring of functional health (sensor networks and telecare integration)
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Electrical/Computer Engineering interface with Medicine
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Wireless sensor networks Embedded systems Electrical and biosignal processing Microelectronics Miniaturisation - nanotechnologies Control systems for heart pumps Computational modeling
IRBP dP sensor
IRBP
LVP sensor
IRBP flow Aortic and PA flow sensors
Retinal Disorders
End Stage RP 5
RP
AMD IEAust 2012
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The Problem
Together, AMD and RP affect at least 30 million people in the world
6,500 cases of RP in Australia and 87,000 in the USA
AMD currently costs Australia $2.6bn p.a.
For RP there is no effective means of restoring vision
Retinitis Pigmentosa (RP)
Age-related Macular Degeneration (AMD)
Oops!!
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Retinal Remodelling
Marc et al, Prog Retinal and Eye Res, 22, 2003
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Blind (A) and Sighted (B) Subjects – Finger Tapping Task
Gizewski et. al., Neuroimage, 19, 2003
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Blind (A) and Sighted (B) Subjects – Reading Braille with Right Hand
Gizewski et. al., Neuroimage, 19, 2003
Brindley, Donaldson and Lewin, 1968
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Optic Nerve Implants
Retinal Implants
Cortical Implants
How Does Our Bionic Eye Work?
1. Camera captures
vision and
transmits data to an
external, body worn
processing unit
4. Implanted
electrode array
stimulates retina
3. Implanted
receiver passes
signals onto retinal
implant
2. Data
processed and
sent to implanted
system via
external wire
5. Electrical
signals sent from
retina via visual
pathway to vision
processing centres
in the brain
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The Olden Days...(1997)
Nigel Lovell UNSW
(Cardiac Research and
Telehealth)
Gregg Suaning Manager of Process
Development Engineering -
Cochlear (Implant Research)
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The Plan Back Then: Human Implants by 2000
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First generation implant One hundred stimulation channels Series stimulation Biphasic constant current waveforms RF (inductively-coupled) data and power Reverse telemetry Ceramic and epoxy package PDMS and platinum electrode array
The Plan Back Then: Human Implants by 2000
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The Reality: Sheep Implants by 2000
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Back to the Drawing Board
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Click Image to Play Video
International Approaches
German – VC funded founded 2003 Clinical trials (Zrenner group)
Second-Sight
US – VC & Govt funded
Clinical trials conducted
Argus II on the EU market
Com
me
rcia
l
German-Swiss – VC & Govt funded
Aca
de
mic
Optoelectronic Retinal Prosthesis (Palanker group)
Mass Eye and Ear / MIT (Rizzo & Wyatt group)
Intelligent Medical
Implants (IMI)
France: Institut de la Vision Paris
Japan: Medicine, Nagoya Uni
Korea: Seoul Artificial Eye Center
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Epi-Ret-3
Optobionics Second Sight Argus I
16 Retina Implant
1500
EpiRet
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IMI
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Second Sight Argus II
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Clinical Trials
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Laboratory and Cleanroom Facility
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External Hardware
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Split Architecture
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Laser Micromachining
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Titanium+
alumina 'hybrid'
Titanium lid
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Ceramic and Titanium Encapsulation
Implant Research:
High Density Ceramic Feedthroughs
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98-Channel Electrode Array
1 2
3
5
4
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Comparison of Laser Cuts
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PDMS Ablation - Excimer Laser
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Electrode Surface Roughening
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98-Channel Electrode Array
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Bioinspiration
Fluorescent images of
Drosophila (fly) retina 42
hours after pupal
development
SEM of an adult fly eye
showing near perfect rows
of ommatidia or unit eyes
arrayed hexagonally
Concurrent Stimulation
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Austriamicrosystems AMS
H35B4D3 4M 2P process
Scalable architecture
98 channels of stimulation
Up to 14 channels
in parallel
Constant current
Biphasic stimuli
Post-stimulus shorting
Monolithic
Reverse telemetry
Quasi-Monopolar
Monolithic Neurostimulation Chip
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Prototype Implanted Device (Eye Unit)
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Does the Device Work?
“What do you see?”
Baa Baa
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The Science: Device Efficacy and Stimulation Strategy
Biomathematical modelling
Surgical placement
In vivo animal experiments (multi- electrode arrays)
In vitro animal experiments (patch clamping, extra-cellular recording, two-photon imaging)
Simulated psychophysics
Human psychophysics …
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Modelling: Current Containment
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Electrode Interaction
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Supra-Choroidal Implantation
Courtesy of Chris Williams,
Penny Allen, BEI/RVEEH
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Device Placement
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Patch Clamp and Sharp Microelectrode Electrophysiology
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The Neural Code
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Two-Photon Microscopy
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Click Image to View Video
Simulated Prosthetic Vision
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Click Image to View Video
Head movement allows identification of difficult
Landolt C items. This movie demonstrates some very
difficult test items, but were all identified correctly by
subject.
Images at NICTA CRL trial environment; various representations
based on depth, intensity, contrast etc.
Incorporating Depth Mapping
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Science Fact or Science Fiction
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Summary
Suprachoroidal space appears to be a viable position for a visual prosthesis
Differentiator - smart visual processing and current steering strategies to create ‘virtual phosphenes’
Human trials of our device this time in 2013
Current neuroprostheses rely on microtechnologies to fabricate and service electrodes >500 m in size (typically interfacing to thousands of nerve fibres)
Unlikely that 1000+ electrode devices will be approved by regulatory bodies in next few years
Either need disruptive technologies to solve the wiring, feedthrough and hermeticity issues or tissue engineering approaches? …
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http://bionic.gsbme.unsw.edu.au
http://www.bionicvision.org.au
facebook.com/bionicvisionaustralia
twitter.com/bionicvision