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Nature Communications Oct 2023Highly reflective surfaces are notorious in the field of depth sensing and three-dimensional (3D) imaging because they can cause severe errors in perception of the...
Highly reflective surfaces are notorious in the field of depth sensing and three-dimensional (3D) imaging because they can cause severe errors in perception of the depth. Despite recent progress in addressing this challenge, there are still no robust and error-free solutions. Here, we devise a polarization structured light 3D sensor for solving these problems, in which high-contrast-grating (HCG) vertical-cavity surface-emitting lasers (VCSELs) are used to exploit the polarization property. We demonstrate accurate depth measurements of the reflective surfaces and objects behind them in various imaging situations. In addition, the absolute error and effective measurement range are measured to prove the applicability for a wide range of 3D applications. Our work innovatively combines polarization and depth information, opening the way for fully understanding and applying polarization properties in the 3D domain.
PubMed: 37891172
DOI: 10.1038/s41467-023-42678-5 -
Sensors (Basel, Switzerland) Aug 2023Depth estimation is an important part of the perception system in autonomous driving. Current studies often reconstruct dense depth maps from RGB images and sparse depth...
Depth estimation is an important part of the perception system in autonomous driving. Current studies often reconstruct dense depth maps from RGB images and sparse depth maps obtained from other sensors. However, existing methods often pay insufficient attention to latent semantic information. Considering the highly structured characteristics of driving scenes, we propose a dual-branch network to predict dense depth maps by fusing radar and RGB images. The driving scene is divided into three parts in the proposed architecture, each predicting a depth map, which is finally merged into one by implementing the fusion strategy in order to make full use of the potential semantic information in the driving scene. In addition, a variant L1 loss function is applied in the training phase, directing the network to focus more on those areas of interest when driving. Our proposed method is evaluated on the nuScenes dataset. Experiments demonstrate its effectiveness in comparison with previous state of the art methods.
PubMed: 37688016
DOI: 10.3390/s23177560 -
IEEE Transactions on Neural Networks... Jul 2023Monocular depth estimation is one of the fundamental tasks in environmental perception and has achieved tremendous progress by virtue of deep learning. However, the...
Monocular depth estimation is one of the fundamental tasks in environmental perception and has achieved tremendous progress by virtue of deep learning. However, the performance of trained models tends to degrade or deteriorate when employed on other new datasets due to the gap between different datasets. Though some methods utilize domain adaptation technologies to jointly train different domains and narrow the gap between them, the trained models cannot generalize to new domains that are not involved in training. To boost the transferability of self-supervised monocular depth estimation models and mitigate the issue of meta-overfitting, we train the model in the pipeline of meta-learning and propose an adversarial depth estimation task. We adopt model-agnostic meta-learning (MAML) to obtain universal initial parameters for further adaptation and train the network in an adversarial manner to extract domain-invariant representations for easing meta-overfitting. In addition, we propose a constraint to impose upon cross-task depth consistency to compel the depth estimation to be identical in different adversarial tasks, which improves the performance of our method and smoothens the training process. Experiments on four new datasets demonstrate that our method adapts quite fast to new domains. Our method trained after 0.5 epoch achieves comparable results with the state-of-the-art methods trained at least 20 epochs.
PubMed: 37410648
DOI: 10.1109/TNNLS.2023.3289051 -
Journal of the National Medical... Dec 2023To determine if there is a racial disparity in satisfaction with maternal healthcare, and examine the quality of care mothers of color receive.
OBJECTIVE
To determine if there is a racial disparity in satisfaction with maternal healthcare, and examine the quality of care mothers of color receive.
METHODS
An online survey of women in the United States who had been pregnant at least once was conducted. The study received an exempt determination by our Institution's Review Board.
RESULTS
Race, age, income, were all significant indicators for whether a woman was satisfied with maternal healthcare measures.
CONCLUSION
Race is one of many indicators for dissatisfaction with maternal healthcare. More in-depth research on patient perception of care is recommended.
Topics: Pregnancy; Female; Humans; United States; Hispanic or Latino; Black or African American; Healthcare Disparities; Mothers; Personal Satisfaction
PubMed: 37845146
DOI: 10.1016/j.jnma.2023.10.001 -
Annual Review of Vision Science Sep 2023This narrative review summarizes the literature on factors related to eye care access and utilization in the United States. Using the Healthy People 2030 framework, this... (Review)
Review
This narrative review summarizes the literature on factors related to eye care access and utilization in the United States. Using the Healthy People 2030 framework, this review investigates social determinants of health associated with general and follow-up engagement, screenings, diagnostic visits, treatment, technology, and teleophthalmology. We provide hypotheses for these documented eye care disparities, featuring qualitative, patient-centered research. Lastly, we provide recommendations in the hopes of appropriately eliminating these disparities and reimagining eye care.
Topics: Humans; Ophthalmology; Telemedicine; Vision Disparity
PubMed: 37254050
DOI: 10.1146/annurev-vision-112122-020934 -
Optometry and Vision Science : Official... Aug 2023Fixation disparity is a small vergence error that does not disrupt fusion. Fixation disparity measures correlate with binocular symptoms. This article covers... (Review)
Review
Fixation disparity is a small vergence error that does not disrupt fusion. Fixation disparity measures correlate with binocular symptoms. This article covers methodological differences between clinical fixation disparity measurement devices, findings when objective and subjective fixation disparities are compared, and the potential impact of binocular capture on fixation disparity measurements. Fixation disparity is a small vergence error that occurs in nonstrabismic individuals and does not disrupt fusion. This article reviews clinical fixation disparity variables and their clinical diagnostic value. Clinical devices that are used to measure these variables are described, as are studies in which the output from these devices has been compared. Methodological differences between the devices such as the location of the fusional stimulus, the rate at which judgments of dichoptic alignment are made, and the strength of the accommodative stimulus are all considered. In addition, the article covers theories of the neural origins of fixation disparity and control system models incorporating fixation disparity. Studies in which objective fixation disparities (oculomotor portion of fixation disparity assessed with an eye tracker) and subjective fixation disparities (sensory portion of fixation disparity assessed psychophysically with dichoptic Nonius lines) have been compared are also examined, and consideration is given to why some investigators find differences in these measures, whereas other investigators do not. The conclusion thus far is that there are likely complex interactions between vergence adaptation, accommodation, and the location of the fusional stimulus that lead to differences in objective and subjective fixation disparity measures. Finally, capture of the visual direction of monocular stimuli by adjacent fusional stimuli and the implications for fixation disparity measures are considered.
Topics: Humans; Fixation, Ocular; Vision Disparity; Eye Movements; Accommodation, Ocular; Judgment; Convergence, Ocular; Vision, Binocular
PubMed: 37436811
DOI: 10.1097/OPX.0000000000002041 -
Rheumatology and Therapy Oct 2023Within the EULAR recommendations, patient education (PE) is stated as the basis of the management of axial spondyloarthritis (axSpA). However, educational needs are...
INTRODUCTION
Within the EULAR recommendations, patient education (PE) is stated as the basis of the management of axial spondyloarthritis (axSpA). However, educational needs are scarcely qualitatively studied in axSpA. Therefore, we aimed to explore experiences and needs of PE in patients with axSpA.
METHODS
A phenomenological approach was used, with semi-structured in-depth interviews with patients with axSpA including broad variation in characteristics. Thematic analysis was applied. To enhance credibility, data saturation, research triangulation, peer debriefing, member checking, theoretical notes, and bracketing were performed.
RESULTS
Three interrelated themes regarding PE were identified from 20 interviews: illness perception, content, and 'availability'. Illness perception affects how patients experience and process PE, which consequently influences coping strategies. Prognosis, treatment, and coaching to self-management were identified as the most important content of PE. Regarding 'availability', face-to-face PE is preferred for exploring needs, supplemented by self-education, which can be freely applied. Additionally, sufficient time and a comprehensible amount of information were important and participants emphasized the need for axSpA-tailored information for relatives and friends. Participants reported a trusting patient-healthcare provider (HCP) relationship, and multidisciplinary and interdisciplinary attunement between HCPs as prerequisites for effective PE.
CONCLUSIONS
This first qualitative study exploring patients' experiences and needs of PE in axSpA revealed that prognosis, treatment, and coaching to self-management are important regarding content, and the combination of face-to-face contact and self-education the preferred modalities. It seems essential that patients' illness perceptions are taken into account for effective PE. These results add relevant insights for future PE guidelines in axSpA.
PubMed: 37523038
DOI: 10.1007/s40744-023-00585-7 -
Cortex; a Journal Devoted To the Study... Jun 2024Understanding the neural substrate of altered conscious states is an important cultural, scientific, and clinical endeavour. Although hypnosis causes strong shifts in...
Understanding the neural substrate of altered conscious states is an important cultural, scientific, and clinical endeavour. Although hypnosis causes strong shifts in conscious perception and cognition, it remains largely unclear how hypnosis affects information processing in cortical networks. Here we manipulated the depth of hypnotic states to study information processing between cortical regions involved in attention and awareness. We used high-density Electroencephalography (EEG) to record resting-state cortical activity from 30 hypnosis experts during two hypnotic states with different depth. Each participant entered a light and a deep hypnotic state as well as two well-matched control states. Bridging top-down and lateralisation models of hypnosis, we found that interhemispheric frontoparietal connectivity distinguished hypnosis and control conditions, while no difference was found between the two hypnotic states. Using a graph-theoretic measure, we revealed that the amount of information passing through individual nodes (measured via betweenness centrality) is reduced during hypnosis relative to control states. Finally, we found that theta power was enhanced during hypnosis. Our result contributes to the current discussion around a role for theta power in bringing about hypnotic states, as well as other altered conscious states. Overall, our findings support the notion that altered top-down control in frontoparietal regions facilitates hypnosis by integrating information between cortical hemispheres.
PubMed: 38865762
DOI: 10.1016/j.cortex.2024.05.008 -
PLoS Computational Biology Jan 2024Naturally occurring collective motion is a fascinating phenomenon in which swarming individuals aggregate and coordinate their motion. Many theoretical models of...
Naturally occurring collective motion is a fascinating phenomenon in which swarming individuals aggregate and coordinate their motion. Many theoretical models of swarming assume idealized, perfect perceptual capabilities, and ignore the underlying perception processes, particularly for agents relying on visual perception. Specifically, biological vision in many swarming animals, such as locusts, utilizes monocular non-stereoscopic vision, which prevents perfect acquisition of distances and velocities. Moreover, swarming peers can visually occlude each other, further introducing estimation errors. In this study, we explore necessary conditions for the emergence of ordered collective motion under restricted conditions, using non-stereoscopic, monocular vision. We present a model of vision-based collective motion for locust-like agents: elongated shape, omni-directional visual sensor parallel to the horizontal plane, and lacking stereoscopic depth perception. The model addresses (i) the non-stereoscopic estimation of distance and velocity, (ii) the presence of occlusions in the visual field. We consider and compare three strategies that an agent may use to interpret partially-occluded visual information at the cost of the computational complexity required for the visual perception processes. Computer-simulated experiments conducted in various geometrical environments (toroidal, corridor, and ring-shaped arenas) demonstrate that the models can result in an ordered or near-ordered state. At the same time, they differ in the rate at which order is achieved. Moreover, the results are sensitive to the elongation of the agents. Experiments in geometrically constrained environments reveal differences between the models and elucidate possible tradeoffs in using them to control swarming agents. These suggest avenues for further study in biology and robotics.
Topics: Humans; Animals; Grasshoppers; Vision, Ocular; Models, Theoretical; Computer Simulation; Motion; Motion Perception; Depth Perception
PubMed: 38285716
DOI: 10.1371/journal.pcbi.1011796 -
Healthcare Technology Letters 2024Root canal therapy (RCT) is a widely performed procedure in dentistry, with over 25 million individuals undergoing it annually. This procedure is carried out to address...
Root canal therapy (RCT) is a widely performed procedure in dentistry, with over 25 million individuals undergoing it annually. This procedure is carried out to address inflammation or infection within the root canal system of affected teeth. However, accurately aligning CT scan information with the patient's tooth has posed challenges, leading to errors in tool positioning and potential negative outcomes. To overcome these challenges, a mixed reality application is developed using an optical see-through head-mounted display (OST-HMD). The application incorporates visual cues, an augmented mirror, and dynamically updated multi-view CT slices to address depth perception issues and achieve accurate tooth localization, comprehensive canal exploration, and prevention of perforation during RCT. Through the preliminary experimental assessment, significant improvements in the accuracy of the procedure are observed. Specifically, with the system the accuracy in position was improved from 1.4 to 0.4 mm (more than a 70% gain) using an Optical Tracker (NDI) and from 2.8 to 2.4 mm using an HMD, thereby achieving submillimeter accuracy with NDI. 6 participants were enrolled in the user study. The result of the study suggests that the average displacement on the crown plane of 1.27 ± 0.83 cm, an average depth error of 0.90 ± 0.72 cm and an average angular deviation of 1.83 ± 0.83°. Our error analysis further highlights the impact of HMD spatial localization and head motion on the registration and calibration process. Through seamless integration of CT image information with the patient's tooth, our mixed reality application assists dentists in achieving precise tool placement. This advancement in technology has the potential to elevate the quality of root canal procedures, ensuring better accuracy and enhancing overall treatment outcomes.
PubMed: 38638496
DOI: 10.1049/htl2.12077