A holographic waveguide based eye tracking device

We demonstrated the feasibility of using a holographic waveguide imager for eye tracking. A holographic waveguide placed in front of the eye was used to capture images of the anterior segment of the eye and to guide the images to a camera distant from the eye. The pupil centre (PC) and corneal reflection (CR) of the eye was used to compute eye position. A custom-built model eye was used to validate the prototype eye tracker. A linear relationship between the angular eye position and the PC/CR vector was found over 60 horizontal degrees and 40 vertical degrees. The tracking accuracy and precision were 0.72 degree and 0.50 degree over these tracking ranges. These results confirmed that holographic waveguide could be a viable platform for developing compact, wearable, see-through eye trackers that can continuously monitor eye movements during real life tasks and thus can facilitate diagnosis of oculomotor disorders.     

Modification of nanostructured fused silica for use as superhydrophobic,IR-transmissive,anti-reflective surfaces

In order to mimic and enhance the properties of moth eye-like materials, nanopatterned fused silica was chemically modified to produce self-cleaning substrates that have anti-reflective and infrared transmissive properties. The characteristics of these substrates were evaluated before and after chemical modification. Furthermore, their properties were compared to fused silica that was devoid of surface features. The chemical modification imparted superhydrophobic character to the substrates, as demonstrated by the average water contact angles which exceeded 170°. Finally, optical analysis of the substrates revealed that the infrared transmission capabilities of the fused silica substrates (nanopatterned to have moth eye on one side) were superior to those of the regular fused silica substrates within the visible and near-infrared region of the light spectrum, with transmission values of 95% versus 92%, respectively. The superior transmission properties of the fused silica moth eye were virtually unchanged following chemical modification.     

Microtopography of the eye surface of the crab Carcinus maenas: an atomic force microscope study suggesting a possible antifouling potential

Marine biofouling causes problems for technologies based on the sea, including ships, power plants and marine sensors. Several antifouling techniques have been applied to marine sensors, but most of these methodologies are environmentally unfriendly or ineffective. Bioinspiration, seeking guidance from natural solutions, is a promising approach to antifouling. Here, the eye of the green crab Carcinus maenas was regarded as a marine sensor model and its surface characterized by means of atomic force microscopy. Engineered surface micro- and nanotopography is a new mechanism found to limit biofouling, promising an effective solution with much reduced environmental impact. Besides giving a new insight into the morphology of C. maenas eye and its characterization, our study indicates that the eye surface probably has antifouling/fouling-release potential. Furthermore, the topographical features of the surface may influence the wettability properties of the structure and its interaction with organic molecules. Results indicate that the eye surface micro- and nanotopography may lead to bioinspired solutions to antifouling protection.     

Probing of human implicit intent based on eye movement and pupillary analysis for augmented cognition

The ultimate purpose of augmented cognition is to enhance human cognitive abilities, which are intrinsically limited. To enhance limited human cognitive abilities, we developed a human augmented cognition system that can offer appropriate information or services by actively responding to the user's intention. This article mainly describes a framework for probing human implicit intentions for the purpose of augmented cognition. The type of user intention, either task‐free human implicit intention or task‐oriented human implicit intention, can be predicted based on fixation count, fixation length, and pupil size variation induced by eye response. Further, these features are used to detect the transition point between task‐free human implicit intention and task‐oriented human implicit intention. Maximum a Posteriori in Naïve Bayes classification model is used for selecting relevant query keywords to search and retrieve specific information from a personalized knowledge database. The experimental results show that the proposed human intention recognition and probing models are suitable for achieving the goal of augmented cognition. © 2013 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 23, 114–126, 2013     

Color harmonies in packaging

The goal of this research was to determine whether or not there was a difference between consumer preferences for color harmonies for products where external labels and visible product existed simultaneously. Using established color theory, transparent packages containing visible products with colored labels were evaluated. Eye tracking metrics and overall preference testing were used to assess these products. Eye tracking data yielded quantitative data that was statistically analyzed using analysis of variance. A post experiment survey was given to participants to collect demographics and additional data was completed through chi‐squared tests for association. No significant difference was found between color harmonies and preference, nor was there significance for the eye tracking metrics. These results of no significance are ideal for designers because it gives them the freedom to use their judgment when designing packaging labels. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 50–59, 2017     

Cardiovascular and eye activity measures as indices for momentary changes in mental effort during simulated flight

This study examines effects of momentary changes in mental effort on cardiovascular and eye activity measures. A total of 19 male pilots performed an instrument flight task. Task load was manipulated by having the pilots perform flight manoeuvres of varying complexity. Multilevel analyses demonstrated clear effects of momentary changes in mental effort on both the cardiovascular and the eye activity measures. An increase in task load resulted in an increase of heart rate and a decrease in heart rate variability, mean dwell time and fixation duration. Heart rate differentiated between resting period and task execution. Heart rate variability from short data segments provided more insight in intermediate levels of mental effort. The eye activity measures were sensitive to intermediate levels of mental effort as well. Attitude changes resulted in an increase of mean dwell time and mean fixation duration. Task analysis is required to use eye measures as valid indices of mental effort. Having indications of the effects of changing mental demands during daily work of operators is of great importance nowadays. This paper presents an approach to estimate such effects on the basis of heart rate and eye activity measures. In particular, the use of averaged short-term heart rate variability measures is a relatively new aspect.     

Electrophoretic coating of amphiphilic chitosan colloids on regulating cellular behaviour

In this communication, we report a facile nanotopographical control over a stainless steel surface via an electrophoretic deposition of colloidal amphiphilic chitosan for preferential growth, proliferation or migration of vascular smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs). Atomic force microscopy revealed that the colloidal surface exhibited a deposition time-dependent nanotopographical evolution, wherein two different nanotopographic textures indexed by ‘kurtosis’ (R_kur) value were easily designed, which were termed as ‘sharp’ (i.e. high peak-to-valley texture) surface and ‘flat’ (i.e. low peak-to-valley texture) surface. Cellular behaviour of VSMCs and HUVECs on both surfaces demonstrated topographically dependent morphogenesis, adherent responses and biochemical properties in comparison with bare stainless steel. The formation of a biofunctionalized surface upon a facile colloidal chitosan deposition envisions the potential application towards numerous biomedical devices, and this is especially promising for cardiovascular stents wherein a new surface with optimized texture can be designed and is expected to create an advantageous environment to stimulate HUVEC growth for improved healing performance.     

基于HOG和SVM的双眼虹膜图像的人眼定位算法

针对近红外光下现有的人眼定位算法普遍存在准确性不高、泛化能力不佳等问题，提出了一种基于方向梯度直方图（HOG）和支持向量机（SVM）相结合的双眼虹膜图像的人眼定位算法。利用HOG提取虹膜图像的人眼特征，并结合SVM分类器对HOG特征进行训练从而实现人眼的精确定位。为了减少漏检和误检，进一步提高定位准确率，又提出了多级级联SVM分类器算法；另外针对近红外光线下虹膜图像独特的灰度分布特点，设计了一种图像预处理方法，能够显著提高人眼定位速度。在MIR2016和CASIA-IRIS-Distance数据集上的实验结果表明，基于HOG和SVM的双眼虹膜图像的人眼定位算法具有高准确率、强泛化能力和高实时性。     

Anthropomorphisms in multimedia learning: Attract attention but do not enhance learning?

Anthropomorphizing graphical elements in multimedia learning materials improves learning outcomes. The reasons for enhanced learning are unclear. We extended a seminal anthropomorphism study in order to examine whether the effect of anthropomorphisms on learning outcomes, both immediate and delayed, is caused by the anthropomorphized elements' effects on attention distribution or by elevated positive affective–motivational states. The study had a partial 3 × 2 design (the materials' graphics: schematic vs. black‐and‐white anthropomorphisms vs. colourful anthropomorphisms × eye tracker: present vs. absent). The participants were university students (N = 181). Unexpectedly, we found no significant effect of anthropomorphisms on learning outcomes. Anthropomorphisms significantly affected attention distribution during initial fixations but not overall. Modest effect on enjoyment was found, but no such effect was detected as concerns flow and generalized positive affect. We also found that the eye tracker's mere presence had slight adverse effects on learners, but these effects did not compromise learning.