Artificial Sight: Basic Research, Biomedical Engineering, and Clinical Advances / Edition 1

by Mark S. Humayun, James D. Weiland, Gerald Chader, Elias Greenbaum

Overview

Artificial sight is a frontier area of modern ophthalmology combining the multidisciplinary skills of surgical ophthalmology, biomedical engineering, biological physics, and psychophysical testing. Many scientific, engineering, and surgical challenges must be surmounted before widespread practical applications can be realized. The goal of Artificial Sight is to summarize the state-of-the-art research in this exciting area, and to describe some of the current approaches and initiatives that may help patients in a clinical setting. The Editors are active researchers in the fields of artificial sight, biomedical engineering and biological physics. They have received numerous professional awards and recognition for their work. The artificial sight team at the Doheny Eye Institute, led by Dr. Mark Humayun, is a world leader in this area of biomedical engineering and clinical research. Key Features Introduces and assesses the state of the art for a broad audience of biomedical engineers, biophysicists, and clinical researchers Describes advances in microelectronics, microfabrication, surgical implantation, and psychophysical testing of visual prostheses Outlines the promise of artificial sight and the challenges that must be met Written for: Researchers and professionals

Product Details

ISBN-13:	9780387493299
Publisher:	Springer New York
Publication date:	10/28/2007
Series:	Biological and Medical Physics, Biomedical Engineering Series
Edition description:	2007
Pages:	400
Product dimensions:	6.10(w) x 9.25(h) x 0.04(d)

About the Author

The Editors are active researchers in the fields of artificial sight, biomedical engineering and biological physics. They have received numerous professional awards and recognition for their work. The artificial sight team at the Doheny Eye Institute, led by Dr. Mark Humayun, is a world leader in this area of biomedical engineering and clinical research.

Table of Contents

Series Preface     v
Preface     vii
List of Contributors     xv
List of Acronyms     xxi
Biological Considerations for an Intraocular Retinal Prosthesis   Hossein Ameri   James D. Weiland   Mark S. Humayun     1
Introduction     1
Background     2
Retinal Implant     19
Summary     25
Artificial Vision: Vision of a Newcomer   Takashi Fujikado   Hajime Sawai   Yasuo Tano     31
Introduction     31
Overall Research Goals of Japanese Consortium for Artificial Retina     32
The Concept of Suprachoroidal-Transretinal Stimulation     32
The Effectiveness of STS in Animal Model     33
Neuroprotection by Electrical Stimulation     39
Human Studies
The Effects of Visual Deprivation: Implications for Sensory Prostheses   Ione Fine     47
Introduction     47
Sensory Plasticity in Adulthood: Potential Differences between Cortical Areas     47
Compensating for a Missing Sense: After Losing a Sense there are Improvements in the Ability to Use the Remaining Senses     50
Compensating for a Missing Sense: What is the Neural Basis?     52
Molyneaux's Question: The Role of Experience in Maintaining Sensory Function     57
Implications for Sensory Prostheses and Rehabilitation     62
Prosthetic Vision Simulation in Fully and Partially Sighted Individuals   Matthias Walter   Liancheng Yang   Gislin Dagnelie     71
Introduction     71
Methods     72
Results     76
Discussion     83
Conclusion     88
Appendix     89
Testing Visual Functions in Patients with Visual Prostheses   Robert Wilke   Michael Bach   Barbara Wilhelm   Wilhelm Durst   Susanne Trauzettel-Klosinski   Eberhart Zrenner     91
Introduction     91
Designing a Test for Visual Functions with Visual Prostheses     94
Implementation of a New Test Battery     95
Conclusion     108
Engineering Applications
The IMI Retinal Implant System   Ralf Hornig   Thomas Zehnder   Michaela Velikay-Parel   Thomas Laube   Matthias Feucht   Gisbert Richard     111
Introduction     111
Retinal Implant Technology     112
Preclinical Studies     119
Clinical Study      120
Conclusions     126
Challenges in Realizing a Chronic High-Resolution Retinal Prosthesis   Wentai Liu   Mohanasankar Sivaprakasam   Guoxing Wang   Mingcui Zhou   James D. Weiland   Mark S. Humayun     129
Introduction     129
External Video Processing Unit     132
Large Stimulation Voltage     133
Stimulation Flexibility     135
Powering of the Retinal Implant     137
Wireless Power Transmission     138
Wireless Data Communication     143
Conclusions     147
Large-scale Integration-Based Stimulus Electrodes for Retinal Prosthesis   Jim Ohta   Takashi Tokuda   Keiichiro Kagawa   Yasuo Terasawa   Motoki Ozawa   Takashi Fujikado   Yasuo Tano     151
Introduction     151
The PFM Photosensor as Subretinal Implantable Device     152
Application of PFM Photosensor to the Stimulation of Retinal Cells     159
Implantation of LSI-based Retinal Prosthesis Devices     162
Summary     166
Development of a Wireless High-Frequency Microarray Implant for Retinal Stimulation   G.W. Auner   R. You   P. Siy    J.P. McAllister   M. Talukder   G.W. Abrams     169
Introduction     169
Wireless Implantable Bio-Device Interface (WIBI)     172
Design of Retinal Prosthesis     178
Experimental Results     184
Conclusion     185
Visual Prosthesis Based on Optic Nerve Stimulation with Penetrating Electrode Array   Qiushi Ren   Xinyu Chai   Kaijie Wu   Chuanqing Zhou$dC-Sight Group     187
Introduction     187
Animal Experiment     189
The Hardware Design of Visual Prosthesis     197
Implantable Micro-Camera in Model Eye     203
Conclusion     206
Stimulating Electrodes
Dynamic Interactions of Retinal Prosthesis Electrodes with Neural Tissue and Materials Science in Electrode Design   Charlene A. Sanders   Evan J. Nagler   David M. Zhou   Elias Greenbaum     209
Introduction     209
Electrochemical Reactions at the Electrode-Vitreous Interface     211
Materials Science in Electrode Design     218
Conclusions     223
In Vitro Determination of Stimulus-Induced pH Changes in Visual Prostheses   A. Chu   K. Morris   A. Agazaryan    A. Istomin   J. Little   R. Greenberg   D. Zhou     227
Introduction     227
Experimental     230
Results     232
Conclusions     240
Electrochemical Characterization of Implantable High Aspect Ratio Nanoparticle Platinum Electrodes for Neural Stimulations   Zhiyu Hu   Dao Min Zhou   Robert Greenberg   Thomas Thundat     243
Introduction     243
Experimental     246
Results and Discussions     248
Conclusions     253
Modeling
High-Resolution Opto-Electronic Retinal Prosthesis: Physical Limitations and Design   D. Palanker   A. Vankov   P. Huie   A. Butterwick   I. Chan   M.F. Marmor   M.S. Blumenkranz     255
Introduction     255
Proximity between Electrodes and Cells as a Resolution-limiting Factor     259
Attracting Retinal Cells to Electrodes     267
Delivery of Information and Power to the Implant     269
Computational Modeling of Electromagnetic and Thermal Effects for a Dual-Unit Retinal Prosthesis: Inductive Telemetry, Temperature Increase, and Current Densities in the Retina   Stefan Schmidt   Carlos J. Cela   Vinit Singh   James Weiland   Mark S. Humayun   Gianluca Lazzi     279
Introduction     280
Inductively Coupled Links for a Dual-Unit Retinal Prosthesis     280
Thermal Modeling     283
Computation of Electric Current Densities in the Retina     294
Results     301
Biological Response to Stimulation
Microstimulation with Chronically Implanted Intracortical Electrodes   Douglas McCreery     307
Introduction     307
The Anatomy and Physiology of the Visual System, as they Relate to a Cortical Visual Prosthesis     308
Microelectrodes for Chronic Intracortical Microstimulation     309
Tissues Responses to Chronically Implanted Microelectrodes     311
Conclusions     321
A Tissue Change After Suprachoroidal-Transretinal Stimulation with High Electrical Current in Rabbits   Kazuaki Nakauchi   Takashi Fujikado   Akito Hirakata   Yasuo Tano     325
Introduction     325
Material and Methods     326
Results     328
Discussion     330
Conclusion     331
Electrical Stimulation of Mammalian Retinal Ganglion Cells Using Dense Arrays of Small-Diameter Electrodes   Chris Sekirnjak    Pawel Hottowy   Alexander Sher   Wladyslaw Dabrowski   Alan M. Litke   E. J. Chichilnisky     333
Introduction     333
Materials and Methods     335
Results     338
Discussion     342
A Mechanism for Generating Precise Temporal Patterns of Activity Using Prosthetic Stimulation   Shelley I. Fried   Hain-Ann Hsueh   Frank Werblin     347
Introduction     347
Methods     348
Results     349
Discussion     353
Electrophysiology of Natural and Artificial Vision   John R. Hetling     355
Introduction     355
Electrophysiology of Natural Vision     357
Electrophysiology of Artificial Vision     366
Summary     378
Index     381