By Topic

Prosthetic Visual Acuity in Irregular Phosphene Arrays Under Two Down-Sampling Schemes: A Simulation Study

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

5 Author(s)
Shanqing Cai ; Dept. of Biomed. Eng., Tsinghua Univ., Beijing ; Lin Fu ; Hui Zhang ; Guangshu Hu
more authors

To investigate the effects of phosphene array irregularity in visual prostheses, a model of phosphenes' positional uncertainty was devised and two different image down-sampling schemes, adapting and non-adapting, were proposed. Based on a simulation system, visual acuity tests were given to four normally sighted subjects under seven degrees of array irregularity and the two down-sampling schemes. With the irregularity index increasing from 0 to 0.6, visual acuity fell over a range of 0.22 logMAR (logarithm of minimum angular resolution) for the adapting scheme and 0.47 logMAR for the non-adapting scheme, both monotonously. Comparison between the two down-sampling schemes was made. For low array irregularity, non-adapting down-sampling afforded higher visual acuity, whereas for higher irregular the adapting approach did. Head movements were observed to play significant roles in the acuity tests

Published in:

Engineering in Medicine and Biology Society, 2005. IEEE-EMBS 2005. 27th Annual International Conference of the

Date of Conference:

17-18 Jan. 2006