Multi-Spectral Clinical Prototype for Fluorophore Detection

Identification of tumour margins during resection of the brain is critical for improving the post-operative outcomes. Current methods of tumour identification use 5-ALA, an exogenous precursor, metabolized to fluorescent PpIX in tumour tissue. Although visible under fluorescent microscope, PpIX is easily photo-bleached and tumour tagging is subjective, resulting in tumour under-resection and accelerated recurrence. To address this issue, photo-bleaching resistant and quantitative method is required. This study describes the characterization of a pulsed, multi-wavelengths system designed to measure diffuse reflectance and auto-fluorescence under strong ambient illumination conditions. The performance was tested on n = 400 liquid tissue phantoms containing a wide concentration range of absorber, scatterer and two fluorophores as well as on ex-vivo samples of gray and white matter. The background subtraction technique was shown to be efficient for a range of ambient illumination intensities. A linear relationship was observed between system response and predicted fluorophore concentrations as well as 97.8% accuracy of tissue classification by 5-fold cross-correlation, linear SVM.

Visual Performance under Varying Illumination Conditions while using an Indigenously Developed Wrist Wearable Computer

Ambient illumination conditions have significant impact on users’ visual performance while carrying out onscreen reading tasks on visual display units, especially smaller screen sizes. Present study assessed the visual performance responses of different ambient illumination levels during onscreen reading on Wrist Wearable Computer (WWC) developed for the command-control-communication between the control room and the soldiers operating in remote locations. Ten (10) Indian Infantry soldiers performed two different types of loud reading tasks on the display of WWC under three different ambient illumination (mean ±SEM) conditions namely, Indoor controlled (450.00±10.00 lx), Outdoor daylight (11818.7±582.91 lx) and Indoor dark (0.12±0.03 lx) environments. While reading, participants wore an eye tracking glass which recorded the eye movement responses. Visualisation techniques were used to predict the association of illumination levelof surrounding with visual performance of the user. Subjective legibility rating was also applied to understand participants’ preferences towards physical attributes of the onscreen information and illumination level. Results indicated that illumination had a significant effect on eye movement parameters like fixation frequency, fixation duration and scanpath length while completing the tasks. Overall, participants performed better under indoor controlled illumination conditions in terms of fixation profile and scanpath length, apart from improved subjective legibility ratings as compared to other two illumination conditions. Future research attempts need to be directed towards the optimum performance of the display across wide range of ambient illumination conditions and to establish how the display of indigenously developed wearable computer performs in comparison to other such displays available across the globe.

P–188 Ambient light intensity and wavelength in the IVF laboratory does not affect life birth rates

Study question Do different wavelengths and intensities in ambient lighting affect clinical outcomes? Summary answer Variations on ambient lighting intensity and wavelength do not affect life birth rates. What is known already Light is one of the factors to consider when designing an IVF laboratory. Most IVF clinics work under reduced illumination, trying to mimic uterine conditions as much as possible. Nevertheless, it has been described that 95% of the light that affects an embryo comes from the microscope, not ambient lighting. It is well accepted that exposure to extreme lighting conditions affects embryos through photo-oxidation and the creation of reactive oxygen species. Still, there is no study that documents the effect of different wavelengths on human embryos. Study design, size, duration Prospective study performed between january 2019 and february 2020. Every 60 days we changed ambient illumination conditions using the LED lighting installed throughout the IVF laboratory. Six different groups were created: Cyan (470nm), Green (550nm), Yellow (600nm), Orange (625nm), intense white (WH), and low intensity white (WL) as control group. Participants/materials, setting, methods A total of 572 egg donation cicles with 355 fresh single embryo transfers were included in the study. In all cycles ICSI and Time-lapse culture was performed (Embryoscope, Vitrolife). PGT and testicular biopsy/aspiration treatments were excluded. Eggs and embryos were exposed to ambient illumination during pick-up, denudation, ICSI, and embryo transfer procedures. Main results and the role of chance Light exposure during embryo/gamete manipulation is inevitable. Hence, we analyzed parameters linked to the success of an IVF cycle to assess the effect of different lighting conditions concluding that neither light color nor intensity affect IVF success rates. No differences were found between groups regarding maternal age, age of the recipient, diagnostic, or number of eggs received (p > 0.05). Fertilization rates were similar between groups (C = 77.04%; G = 73.72%; Y = 75.64%; O = 78.1%; WL = 76.4%; WH = 75.2%; p = 0.216) as well as good quality blastocyst rates (C = 57.35%; G = 57.37%; Y = 62.30%; O = 59.75%; WL = 63.28%; WH = 60.55%; p = 0.234). Regarding clinical outcomes both implantation and miscarriage rates were found to be equal between groups (C = 61.67%; G = 52.89%; Y = 55.10%; O = 66.18%; WL = 66.00%; WH = 53.55%; p = 0.194, and C = 24.32%; G = 19.15%; Y = 11.11%; O = 24.44%; WL = 15.15%; WH = 8.11%; p = 0.301). The main outcome for this study was live birth rates and no differences were found (C = 51.85%; G = 50.00%; Y = 52.17%; O = 53.97%; WL = 57.14%; WH = 50.75%; p = 0.168). Limitations, reasons for caution We must take into account that embryos were cultured inside a time-lapse incubator, diminishing the effect of ambient light. Wider implications of the findings: This study demonstrates that, with advances in culture technology, neither light intensity nor light wavelength affecting gametes/embryos during manipulation influence clinical outcomes. Trial registration number Not applicable

Robust Discriminative Analysis Framework for Gaze and Headpose Estimation

Head movements, combined with gaze, play a fundamental role in predicting a person’s action and intention. In non-constrained head movement settings, the process is complex, and performance can degrade significantly in the presence of variation in head-pose, gaze position, occlusion and ambient illumination. In this thesis, a framework is therefore proposed to fuse and combine head-pose and gaze information to obtain more robust and accurate gaze estimation. Specific contributions include: the development of a newly developed graph-based model for pupil localization and accurate estimation of the pupil center; the proposal of a novel iris region descriptor feature using quadtree decomposition, that works together with pupil localization for gaze estimation; the proposal of kernel-based extensions and enhancements to a fusion mechanism known as Discriminative Multiple Canonical Correlation Analysis (DMCCA) for fusing features (proposed and traditional) together, to generate a refined, high quality feature set for classification; and the newly developed methodology of head-pose features based on quadtree decompositions and geometrical moments, to better integrate roll, yaw, pitch and jawline into the overall estimation framework. The experimental results of the proposed framework demonstrate robustness against variations in illumination, occlusion, head-pose and is calibration free. The proposed framework was validated on several datasets and scored: 4.5° using MPII, 4.4° using Cave, 4.8° using EYEDIAP, 5.0° using ACS, 4.1° using OSLO and 4.5° using UULM datasets respectively.

Robust Discriminative Analysis Framework for Gaze and Headpose Estimation

Head movements, combined with gaze, play a fundamental role in predicting a person’s action and intention. In non-constrained head movement settings, the process is complex, and performance can degrade significantly in the presence of variation in head-pose, gaze position, occlusion and ambient illumination. In this thesis, a framework is therefore proposed to fuse and combine head-pose and gaze information to obtain more robust and accurate gaze estimation. Specific contributions include: the development of a newly developed graph-based model for pupil localization and accurate estimation of the pupil center; the proposal of a novel iris region descriptor feature using quadtree decomposition, that works together with pupil localization for gaze estimation; the proposal of kernel-based extensions and enhancements to a fusion mechanism known as Discriminative Multiple Canonical Correlation Analysis (DMCCA) for fusing features (proposed and traditional) together, to generate a refined, high quality feature set for classification; and the newly developed methodology of head-pose features based on quadtree decompositions and geometrical moments, to better integrate roll, yaw, pitch and jawline into the overall estimation framework. The experimental results of the proposed framework demonstrate robustness against variations in illumination, occlusion, head-pose and is calibration free. The proposed framework was validated on several datasets and scored: 4.5° using MPII, 4.4° using Cave, 4.8° using EYEDIAP, 5.0° using ACS, 4.1° using OSLO and 4.5° using UULM datasets respectively.

The sensory impacts of climate change: bathymetric shifts and visually mediated interactions in aquatic species

Visual perception is, in part, a function of the ambient illumination spectrum. In aquatic environments, illumination depends upon the water's optical properties and depth, both of which can change due to anthropogenic impacts: turbidity is increasing in many aquatic habitats, and many species have shifted deeper in response to warming surface waters (known as bathymetric shifts). Although increasing turbidity and bathymetric shifts can result in similarly large changes to a species' optical environment, no studies have yet examined the impact of the latter on visually mediated interactions. Here, we examine a potential link between climate change and visual perception, with a focus on colour. We discuss (i) what is known about bathymetric shifts; (ii) how the impacts of bathymetric shifts on visual interactions may be distributed across species; (iii) which interactions might be affected; and (iv) the ways that animals have to respond to these changes. As warming continues and temperature fluctuations grow more extreme, many species may move into even deeper waters. There is thus a need for studies that examine how such shifts can affect an organism's visual world, interfere with behaviour, and impact fitness, population dynamics, and community structure.

Effect of Ambient Illumination, Screen Resolution and Zoom Level on Performance of Typing on Computers

Objective: This work aims to investigate effect of the ambient illumination, screen resolution and Zoom levels on visual-related task performance. The job used in this research is typing on computers. Speed of typing paragraph and typing quality were defined as the task performance. Background: In recent years, computers play a remarkable role in nearly everyone’s daily life. We use computers for various purposes and under a wide range of ambient illumination. High illumination level usually results in some problems. Adjusting screen resolution and zoom level are common solutions contra problems for visibility due to unsuitable illuminations. Method: Ambient illuminations were examined 114, 230, 340, 420 and 520 lx. Screen resolution scales were diverse to cover all range of regulate ability pliable by characteristics of the offering used; 768*1024, 720*1280 and 768*1366. Zoom levels was tested 50, 100, 150 and 200%. Results: Based on this study, can be found that, the more effective illumination level on average typing time was 340 followed by 420 lx. Average typing time decrease with increasing screen resolution, the minimum average typing time observed at 720*1280 and 168*1366 screen resolution. Change the zoom level of text show significant effect on typing time, which the average typing time decreases with increasing zoom level. The minimum typing time observed at 100 and 150% zoom level. Experimental results for all S/N ratio, mean, and standard deviation (real) response values show that, illumination level, screen resolution and zoom scale are the significant parameters among all controllable factors that influence the avearge typing time. Based on S/N Ratio the optimum parameters was 114 lx illumination level and 768*1024 screen Resolution and 50% zoom level. Based on standard deviation the optimum parameters was 114 lx illumination level and 768*1366 screen Resolution and 150% zoom level. Based on the means the optimum parameters was is 230lx illumination level and 768*1366 screen Resolution and 100% zoom level. Conclusion: The provision of suitable illumination, screen resolution and zoom levels that feedback to enhancing the performance of typing performance on computers. Application: This study can inform in-computer typing offices and policy makers concerned with human factors and work-study.