Title
High Performance 3-Coil Wireless Power Transfer System For The 512-Electrode Epiretinal Prosthesis
Abstract
The next-generation retinal prostheses feature high image resolution and chronic implantation. These features demand the delivery of power as high as 100 mW to be wireless and efficient. A common solution is the 2-coil inductive power link, used by current retinal prostheses. This power link tends to include a larger-size extraocular receiver coil coupled to the external transmitter coil, and the receiver coil is connected to the intraocular electrodes through a trans-sclera trans-choroid cable. In the long-term implantation of the device, the cable may cause hypotony (low intraocular pressure) and infection. However, when a 2-coil system is constructed from a small-size intraocular receiver coil, the efficiency drops drastically which may induce over heat dissipation and electromagnetic field exposure. Our previous 2-coil system achieved only 7% power transfer. This paper presents a fully intraocular and highly efficient wireless power transfer system, by introducing another inductive coupling link to bypass the trans-sclera trans-choroid cable. With the specific equivalent load of our customized 512-electrode stimulator, the current 3-coil inductive link was measured to have the overall power transfer efficiency around 36%, with 1-inch separation in saline. The high efficiency will favorably reduce the heat dissipation and electromagnetic field exposure to surrounding human tissues. The effect of the eyeball rotation on the power transfer efficiency was investigated as well. The efficiency can still maintain 14.7% with left and right deflection of 30 degree during normal use. The surgical procedure for the coils' implantation into the porcine eye was also demonstrated.
Year
DOI
Venue
2012
10.1109/EMBC.2012.6347503
2012 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)
Field
DocType
Volume
Deflection (engineering),Transmitter,Wireless power transfer,Wireless,Inductive coupling,Computer science,Electronic engineering,Electromagnetic coil,Maximum power transfer theorem,Electrical engineering,Electromagnetic field
Conference
2012
ISSN
Citations 
PageRank 
1557-170X
5
0.64
References 
Authors
3
4
Name
Order
Citations
PageRank
Yu Zhao1384.42
Mandheerej Nandra250.64
Chia-Chen Yu350.64
Yu-chong Tai450.64