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Accurate and Robust eye Center Localization via Fully Convolutional Networks

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IEEE/CAA Journal of Automatica Sinica 2019年第5期6卷 1127-1138页

作者： Yifan Xia Hui Yu Fei-Yue Wang the School of Creative Technologies University of PortsmouthPortsmouthPO1 2DJUK the State Key Laboratory of Management and Control for Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China

eye center localization is one of the most crucial and basic requirements for some human-computer interaction applications such as eye gaze estimation and eye tracking. There is a large body of works on this topic in recent years, but the accuracy still needs to be improved due to challenges in appearance such as the high variability of shapes, lighting conditions, viewing angles and possible occlusions. To address these problems and limitations, we propose a novel approach in this paper for the eye center localization with a fully convolutional network(FCN),which is an end-to-end and pixels-to-pixels network and can locate the eye center accurately. The key idea is to apply the FCN from the object semantic segmentation task to the eye center localization task since the problem of eye center localization can be regarded as a special semantic segmentation problem. We adapt contemporary FCN into a shallow structure with a large kernel convolutional block and transfer their performance from semantic segmentation to the eye center localization task by fine-tuning.Extensive experiments show that the proposed method outperforms the state-of-the-art methods in both accuracy and reliability of eye center localization. The proposed method has achieved a large performance improvement on the most challenging database and it thus provides a promising solution to some challenging applications.

关键词： Deep learning eye center localization eye gaze estimation eye tracking fully convolutional network (FCN) humancomputer interaction

Synchronization between frontal eye field and area V4 during free-gaze visual search

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Zoological Research 2019年第5期40卷 394-403页

作者： Ting Yan Hui-Hui Zhou Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences

Information flow between the prefrontal and visual cortices is critical for visual behaviors such as visual search. To investigate its mechanisms, we simultaneously recorded spike and local field potential (LFP) signals in the frontal eye field (FEF) and area V4 while monkeys performed a free-gaze visual search task. During free-gaze search, spike-LFP coherence between FEF and V4 was enhanced in the theta rhythm (4–8 Hz) but suppressed in the alpha rhythm (8–13 Hz). Cross-frequency couplings during the Cue period before the search phase were related to monkey performance, with higher FEF theta-V4 gamma coupling and lower FEF alpha-V4 gamma coupling associated with faster search. Finally, feature-based attention during search enhanced spike-LFP coherence between FEF and V4 in the gamma and beta rhythms, whereas overt spatial attention reduced coherence at frequencies up to 30 Hz. These results suggest that oscillatory coupling may play an important role in mediating interactions between the prefrontal and visual cortices during visual search.

关键词： Synchronization Frontal eye field (FEF) V4 Visual search

Passive eye movements induced by electromagnetic force(EMF) in rats

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Zoological Research 2019年第3期40卷 211-218页

作者： Yue Yu Jun Huang Chun-Ming Zhang Tian-Wen Chen David S.Sandlin Shao-Xun Wang Alberto A.Arteaga Jerome Allison Yang Ou Susan Warren Paul May Hong Zhu Wu Zhou Departments of Otolaryngology and Communicative Sciences University of Mississippi Medical CenterJackson MS 39216USA Department of Otolaryngology First Affiliated HospitalShanxi Medical UniversityTaiyuan Shanxi 030001China MD/PhD Program University of Mississippi Medical CenterJackson MS 39216USA Pharmacology and Toxicology University of Mississippi Medical CenterJackson MS 39216.USA Neurobiology and Anatomical Sciences University of Mississippi Medical CenterJackson MS 39216USA Neurology University of Mississippi Medical CenterJackson MS 39216USA

Accurate information on eye position in the orbit is available from visual feedback,efference copy of the oculomotor commands and proprioceptive signals from the extraocular muscles (EOM).Whereas visual feedback and oculomotor commands have been extensively studied,central processing of EOM proprioceptive signals remains to be elucidated.A challenge to the field is to develop an approach to induce passive eye movements without physically contacting the eyes.A novel method was developed to generate passive eye movements in rats.A small rare-earth magnet disk (0.7 mm diameter,0.5 mm thickness) was attached to the surface of a rat's eyeball.A metal rod (5 mm diameter) wrapped with an electromagnetic (EM) coil was placed near the magnet (8-15 mm).By passing currents to the EM coil,electromagnetic force (EMF) was generated and acted upon the magnet and induced passive eye movements.The EMF induced well-defined passive eye movements,whose directions were dependent on current polarity and amplitudes and peak velocities were dependent on current intensity and duration.Peak velocities of the EMF-induced eye movements were linearly related to amplitudes,exhibiting main sequence relationships similar to that of saccades in awake rats and eye movements induced by electrical microstimulation of the abducens nucleus in anesthetized rats.Histological examination showed that repetitive EMF stimulations did not appear to result in damages in the EOM fibers.These results validated the EMF approach as a novel tool to investigate EOM proprioceptive signals and their roles in visual localization and gaze control.

关键词： eye movement Proprioception Extraocular muscles Stretch reflex

具有12.37%的光电转换效率及18.6%的平均可见光透过率的半透明聚合物太阳能电池

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Science Bulletin 2020年第2期65卷 131-137,88页

作者：胡拯豪王智安桥石张福俊 Key Laboratory of Luminescence and Optical Information Ministry of EducationBeijing Jiaotong UniversityBeijing 100044China School Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China

本文制备了一系列以PM6为给体、窄带隙材料Y6为受体的聚合物太阳能电池,分别以100 nm铝或1 nm金/(20,15,10 nm)银作为电极来制备不透明及半透明器件.以不透明器件为基础,优化有源层的厚度,当有源层厚度为100 nm时,器件的光电转换效率达... 详细信息

本文制备了一系列以PM6为给体、窄带隙材料Y6为受体的聚合物太阳能电池,分别以100 nm铝或1 nm金/(20,15,10 nm)银作为电极来制备不透明及半透明器件.以不透明器件为基础,优化有源层的厚度,当有源层厚度为100 nm时,器件的光电转换效率达到了15.83%.100 nm厚的混合薄膜的平均可见光透过率为50.5%,这表明利用该有源层有望制备出高效率半透明聚合物太阳能电池.分别以1 nm金/20 nm银,1 nm金/15 nm银,1 nm金/10nm银复合电极代替铝电极(这种金/银复合电极在可见光范围内透过率较高,在近红外光范围透过率较低),所制备的半透明聚合物太阳能电池的光电转换效率和平均可见光透过率分别达到了14.20%和8.9%,13.32%和12.5%,12.37%和18.6%,这处于目前报道的半透明聚合物太阳能电池性能最高的行列.这一工作表明:开发高可见光透过率、低近红外光透过率电极以及使用窄带隙材料为有源层是制备高效率半透明聚合物太阳能电池的有效方法.

关键词： Semitransparent polymer solar cells Narrow band gap materials Semitransparent electrode Power conversion efficiency Average visible transmittance Photopic response of human eye

Assessing gray matter volume in patients with idiopathic rapid eye movement sleep behavior disorder

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Neural Regeneration Research 2019年第5期14卷 868-875页

作者： Xian-Hua Han Xiu-Ming Li Wei-Jun Tang Huan Yu Ping Wu Jing-Jie Ge Jian Wang Chuan-Tao Zuo Kuang-Yu Shi PET Center Huashan Hospital Fudan University Department of Radiology Huashan Hospital Fudan University Department of Neurology Huashan Hospital Fudan University Department of Nuclear Medicine Technical University Munich

Idiopathic rapid eye movement sleep behavior disorder(iRBD) is often a precursor to neurodegenerative disease. However, voxel-based morphological studies evaluating structural abnormalities in the brains of iRBD patients are relatively rare. This study aimed to explore cerebral structural alterations using magnetic resonance imaging and to determine their association with clinical parameters in iRBD patients. Brain structural T1-weighted MRI scans were acquired from 19 polysomnogram-confirmed iRBD patients(male:female 16:3; mean age 66.6 ± 7.0 years) and 20 age-matched healthy controls(male:female 5:15; mean age 63.7 ± 5.9 years). Gray matter volume(GMV) data were analyzed based on Statistical Parametric Mapping 8, using a voxel-based morphometry method and two-sample t-test and multiple regression analysis. Compared with controls, iRBD patients had increased GMV in the middle temporal gyrus and cerebellar posterior lobe, but decreased GMV in the Rolandic operculum, postcentral gyrus, insular lobe, cingulate gyrus, precuneus, rectus gyrus, and superior frontal gyrus. iRBD duration was positively correlated with GMV in the precuneus, cuneus, superior parietal gyrus, postcentral gyrus, posterior cingulate gyrus, hippocampus, lingual gyrus, middle occipital gyrus, middle temporal gyrus, and cerebellum posterior lobe. Furthermore, phasic chin electromyographic activity was positively correlated with GMV in the hippocampus, precuneus, fusiform gyrus, precentral gyrus, superior frontal gyrus, cuneus, inferior parietal lobule, angular gyrus, superior parietal gyrus, paracentral lobule, and cerebellar posterior lobe. There were no significant negative correlations of brain GMV with disease duration or electromyographic activity in iRBD patients. These findings expand the spectrum of known gray matter modifications in iRBD patients and provide evidence of a correlation between brain dysfunction and clinical manifestations in such patients. The protocol was approved by the Ethics Committee of Huashan Hospital(approval No.

关键词： nerve regeneration idiopathic rapid eye movement sleep behavior disorder synucleinopathies magnetic resonance imaging gray matter volume statistic parametric mapping voxel-based morphometry structure Parkinson’s disease neurodegenerative diseases neural regeneration

The Schlager mouse as a model of altered retinal phenotype

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Neural Regeneration Research 2020年第3期15卷 512-518页

作者： Lakshini Y.Herat Aaron L.Magno Márcio G.Kiuchi Kristy L.Jackson Revathy Carnagarin Geoffrey A.Head Markus P.Schlaich Vance B.Matthews Dobney Hypertension Centre School of Biomedical Science-Royal Perth Hospital UnitUniversity of Western AustraliaPerthAustralia Research Centre Royal Perth HospitalPerthAustralia Dobney Hypertension Centre School of Medicine-Royal Perth Hospital UnitUniversity of Western AustraliaPerthAustralia Neuropharmacology Laboratory Baker Heart and Diabetes InstituteMelbourneAustralia Department of Cardiology and Department of Nephrology Royal Perth HospitalPerthAustralia

Hypertension is a risk factor for a large number of vision-threatening eye disorders.In this study,we investigated for the first time the retinal neural structure of the hypertensive BPH/2J mouse(Schlager mouse)and compared it to its control counterpart,the normotensive BPN/3J strain.The BPH/2J mouse is a selectively inbred mouse strain that develops chronic hypertension due to elevated sympathetic nervous system activity.When compared to the BPN/3J strain,the hypertensive BPH/2J mice showed a complete loss of outer layers of the neural retina at 21 weeks of age,which was indicative of a severe vision-threatening disease potentially caused by hypertension.To elucidate whether the retinal neural phenotype in the BPH/2J strain was attributed to increased BP,we investigated the neural retina of both BPN/3J and BPH/2J mice at 4 weeks of age.Our preliminary results showed for the first time that the BPH/2J strain develops severe retinal neural damage at a young age.Our findings suggest that the retinal phenotype in the BPH/2J mouse is possibly due to elevated blood pressure and may be contributed by an early onset spontaneous mutation which is yet to be identified or a congenital defect occurring in this strain.Further characterization of the BPH/2J mouse strain is likely to i)elucidate gene defects underlying retinal disease;ii)understand mechanisms leading to neural retinal disease and iii)permit testing of molecules for translational research to interfere with the progression of retinal disease.The animal experiments were performed with the approval of the Royal Perth Hospital Animal Ethics Committee(R535/17-18)on June 1,2017.

关键词： blood pressure eye hypertension mice neural regeneration retina Schlager mouse sympathetic nervous system

Daily expression of two circadian clock genes in compound eyes of Helicoverpa armigera: evidence for peripheral tissue circadian timing

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Insect Science 2019年第2期26卷 217-228页

作者： Shuo Yan Yan-Jun Liu Jia-Lin Zhu Wei-Na Cui Xin-Fang Zhang Yu-Hui Yang Xiao-Ming Liu Qing-Wen Zhang Xiao-Xia Liu Department of Entomology China Agricultural University Beijing China National Agricultural Technology Extension and Service Center Beijing China Beijing Entry-Exit Inspection and Quarantine Bureau Beijing China Zoucheng Plant Protection Station Zoucheng Shandong Province China Changli Institute of Pomology Hebei Academy of Agriculture and Forestry Sciences Changli Hebei Province China

Circadian clock genes in peripheral tissues usually play an important role in regulating the circadian rhythms. Light is the most important environmental signal for synchronizing endogenous rhythms with the daily light-dark cycle, and compound eyes are known as the principal circadian photoreceptor for photic entrainment in most moths. However, there is little evidence for circadian timing in compound eyes. In the current study, we isolated the timeless gene, designated Ha-tim (GenBank accession number: KM233162), from the cotton bo 11 worm Helicoverpa armigera. Ha-tim and period (Haper) showed low messenger RNA levels in the compound eyes compared to the other tested adult organs. Ha-tim and Ha-per transcript levels were dependent on an endogenous rhythm that fluctuated over a daily cycle in the compound eyes and heads. The cycles of Hatim and Ha-per transcript levels followed similar time courses, and identical expression patterns of the two genes were observed in the compound eyes and heads. Ha-tim and Ha-per were dowregulated in the compound eyes after light exposure, copulation and starvation. These results indicated that Ha-tim and Ha-per transcript levels were regulated by endogenous and exogenous factors. Our study helped to improve our understanding of the circadian clock machinery in compound eyes and other peripheral tissues.

关键词： circadian clock compound eye photoreceptor period timeless rhythm

karmoisin and cardinal ortholog genes participate in the ommochrome synthesis of Nilaparvata lugens (Hemiptera:Delphacidae)

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Insect Science 2019年第1期26卷 35-43页

作者： Shu-Hua Liu Ju Luo Bao-Jun Yang Ai-Ying Wang Jian Tang State Key Laboratory of Rice Biology China National Rice Research InstituteHangzhouChina

Ommochrome is the major source for eye coloration of all insect species so far examined.Phenoxazinone synthetase (PHS)has always been regarded as the terminal step enzyme for ommochrome formation,which is encoded by cardinal or karmoisin genes. Our previous study indicated that the karmoisin ortholog gene (Nl-karmoisin)product in the brown planthopper (BPH)was a monocarboxylate transporter,while not a PHS. Here,based on full-length complementary DNA,the cardinal ortholog gene in BPH (Nl-cardinal)product was predicted to be a haem peroxidase rather than a PHS.We suggest for the first time that neither karmoisin nor cardinal encodes the PHS,but whether PHS participates in BPH eye pigmentation needs further research.Nymphal RNA interference (RNAi)experiments showed that knockdown Nl-cardinal transcript led the BPH ocelli and compound eye to color change from brown to red,while knockdown Nl-karmoisin only made the ocelli present the red phenotype.Notably,not only the Nl-cardinal transcript, dscd injection (Nl-cardinal targeting double-stranded DNA (dsRNA))also significantly reduced the Nl-karmoisin transcript by 33.7%,while dska (Nl-karmoisin targeting dsRNA) injection did not significantly change the Nl-cardinal transcript.Considering the above RNAi and quantitative real-time polymerase chain reaction results,we propose that Nl-cardinal plays a more important role in ommochrome synthesis than Nl-karmoisin,and it may be an upstream gene of Nl-karmoisin.The present study suggested that both karmoisin and cardinal ortholog genes play a role in ommochrome synthesis in a hemimetabolous insect.

关键词： cardinal eye color karmoisin Nilaparvata lugens ommochrome phenoxazinone synthetase

eye pathologies in neonates

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International Journal of Ophthalmology(English edition) 2016年第12期9卷 1832-1838页

作者： Nyaish Mansoor Thami Marrsoor Mansoor Ahmed Leeds School of Medicine University of Leeds LS2 9JTUnited Kingdom Queen's Hospital Burton Upon Trent DE13 ORB United Kingdom

In the United Kingdom, newborn assessment incorporates a screening eye examination for any structural abnormalities, observation of neonate’s visual behaviour and direct ophthalmoscopy examination looking for red reflex. Early identification and immediate management of eye related pathologies should commence soon after birth as early diagnosis and prompt intervention may have significant impact on the prognosis for many potentially blinding but treatable disorders such as congenital cataracts and retinoblastoma. If left undetected and untreated, such problems may potentially lead to irreversible damage to the vision which persists into adulthood resulting in lack of self-confidence together with difficulties in educational attainment and job opportunities.

关键词： newborn eye screening congenital cataract retinoblastoma