Visual Prosthesis
(Retinal Implant & Biohybrid
Retinal Implant)
Abstract
A visual prosthesis is an artificial organ to restore the sight of blind patients with electrical stimulation to the visual nervous system. Dr. Yagi has been conducting two types of the visual prosthesis; a biohybird implant and a retinal implant.
In academia, Dr. Yagi's group has been conducting basic research and system design/integration on a biohybird retinal implant, which consists of cultured neurons on MEMS (Microelectromechanical Systems). Axons of the neurons will be guided with an axon-guiding material such as a peripheral nerve graft, or a tube, which is filled with the Schwann cells and the extra cellular matrix. Therefore, the transplanted neurons will be used as living electric wires in order to connect the MEMS and the central nervous system. Since the hybrid retinal implant requires neither the retinal ganglion cells nor the optic nerve, it will be more applicable to blind diseases where the retinal ganglion cells and/or the optic nerve are NOT intact.
Biohybird retinal implant
Biohybird retinal implant project includes; development of various micro-electrode arrays with MEMS technology including a conductive polymer microelectrode array, in vitro nerve cell culture and axon guidance experiments on the fabricated microelectrode array, in vivo electrical stimulation experiments, and various computer simulations including psycho-physical evaluation of reading ability with the visual prosthesis simulator.
In industry, Dr.Yagi has directed his R&D team in industry under the support of a Japanese national research project of a visual prosthesis. His visual prosthesis consists of an extra-ocular and an intra-ocular device, and contains various technologies such as image capture and processing, wireless data&power transmission, data&power recovery and pulse generation on a full-custom IC, and electronics packaging of the fabricated IC and a stimulation electrode array. According to the visual information captured by a video camera in the extra-ocular device, the information is coded, then sent to the intra-ocular device through an infrared (IR) communication unit. After the intra-ocular device receives the IR data, it generates adequate electric pulses for stimulating the retina. The first prototype of the retinal implant was completed 2004 spring, and will be evaluated in animal and clinical tests near future.
Links
Retinal Implant
- US Group 1
- Mass. Eye and Ear Infirmary, Harvard Medical School (Prof. Rizzo)
- Circuits and Systems Group of the Research Laboratory of Electronics, MIT (Prof. Wyatt)
- US Group 2
- Second Sight LLC. (Dr. Greenberg)
- University of Southern California (Prof. de Juan, Pfor. Humayun, Prof. Weiland)
- Johns Hopkins University (Prof. Dagnelie)
- University of California, Santa Crurz (Prof. Liu)
- US Group 3
- Optobionics Corp. (Dr. Chow) (Dismissal in 2007)
- US Group 4
- The Kresge Eye Institute, Wayne Sate University School of Medicine (Prof. Abrams, Prof. Iezzi)
- College of Engineering, Wayne Sate University (Prof. Auner)
- US
Group 5
- Stanford University (Prof. Palanker)
- US
Group 6
- University of Houston (Prof. Ignatiev)
- German Group 1
- University Eye Hospital Tueingen (Prof.Zrenner)
- University Eye Hospital Regensburg (Prof. Gabel)
- Retina Implant AG
- German Group 2
- Aachen University (Prof.Walter)
- University of Bonn (Prof.Eckmiller)
- University of Duisburg
- German Group 3
- Intelligent Medical Implants
- UK Group 1
- Imperial College London (Dr Patrick Degenaar)
- UK Group 2
- University of Glasgow (Dr Mathieson, Dr Morrison)
- Japanese Group 1
- Japanese Group 2
- Japanese Group 3
- Okayama University (Prof. Matsuo, Prof. Shimamura)
- Hayashibara Co., Ltd.
- Japanese Group 4
- Australian
Group
- University of New South Wales (Prof.Lovell)
- University of New Southwales (Prof.Suaning)
- Bionic Vision Australia
- Korean Group
- Seoul National University (Prof.Kim, Prof. Seo)
- Chinese Group
- Shanghai Jiao-Tong University (Prof.Ren)
Optic Nerve Implant
- Belgium
Group
- University of Catholique de Louvain, Neural Rehabilitation Engineering Lab (Dr. Jean Delbeke, Dr. Veraart)
- University of Catholique de Louvain, Microelectronics Lab (Dr. Trullemans)
Cortical Implant
- US Group 7
- The Dobelle Group (Dr.Dobelle) (Dismissal in 2004)
- US
Group 8
- University of Utah (Prof. Normann)
- US Group 9
- Illinois Institute of Technology (Prof. Troyk)
- Spain Group
- University Miguel Hermandez (Prof. Fernandez)
- Canadian Group
- Ecole Polytechnique de Montreal (Prof. Sawan Mohamad)
Other related links
- Neural Prosthesis Program
- The
Eye and The Chip
- Detroit Eye Institute (Dr. Hessburg)