title: Correction for Chinese character patterns formed by simulated irregular phosphene map.
abstract: To reduce the unfavorable influence of phosphene array irregularity on the form of Chinese character pattern so as to improve recognition accuracy in visual prostheses, two correction methods were put forward. One method was to generate phosphene closest to the target point in regular arrays using weighted nearest neighbor search. The other was to generate phosphene whose center located in the region covered by dilated characters. Based on a simulation system, Chinese character recognition tests were given to fifteen normally sighted subjects under five degrees of array irregularity (0.2, 0.4, 0.6, 0.8, 1.0) without correction. The recognition accuracy decreased with the increase of irregularity. When the recognition accuracy dropped below 80%, two correction methods were applied and their effects were evaluated. With the increase of array irregularity, both effects on the accuracy of recognition grew considerably. Comparison between the two methods revealed that the former method afforded higher recognition accuracy and the latter only applied to phosphene map with serious irregularity.
authors.affiliation: Department of Biomedical Engineering, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 200240, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Dai
authors.forename: Manman
authors.initials: M
authors.lastname: Lu
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yanyu
authors.initials: Y
authors.lastname: Lu
authors.forename: Chuanqing
authors.initials: C
authors.lastname: Zhou
authors.forename: Yao
authors.initials: Y
authors.lastname: Chen
authors.forename: Qiushi
authors.initials: Q
authors.lastname: Ren
authors.forename: Xinyu
authors.initials: X
authors.lastname: Chai
mesh_terms: D000328:Adult; D003198:Computer Simulation; D006801:Humans; D007802:Language; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010719:Phosphenes / Q000502:physiology*; D010775:Photic Stimulation; D055815:Young Adult