An Artificial Optoelectronic Nociceptor Based on In2S3 Memristor

Nociceptors are an indispensable part of the human nervous system that can sense potential dangers from external environmental stimuli. The biomimetic studies of artificial nociceptors have inspired advanced technology in neuromorphic computing, humanoid robots and artificial visual sensors. In this work, we demonstrate an artificial optoelectronic nociceptor using the memristor of large-area In2S3 thin films. The nociceptor responses not only to electrical stimuli but also illumination of visual light, showing complete nociceptive behaviors of "threshold", "inadaptation", "flabby" and "sensitization". The features of the sensory signal such as responding threshold, relaxation time and sensitivity can be tuned in controllable manner, by the strength and frequency of the external stimuli as well as the biasing of electrostatic gate. Such realization of sensory response to multiple external stimuli in the artificial perceptron demonstrates the feasibility of constructing advanced electronic receptor and artificial human eye.

TOWARDS A FRAMEWORK FOR LIGHT-DOSIMETRY STUDIES: METHODOLOGICAL CONSIDERATIONS

For field research of non-visual effects of light, accurate measurement of personal light exposure is required. A consensus framework for light-dosimetry could improve non-visual field research and ensure comparability between studies. Here we present a review of methodologies used in non-visual light-dosimetry studies published to date, focussing on considerations regarding the measurement and preparation of personal light exposure data. Overall, a large variability in the studies’ methodologies is observed, highlighting the need for a consensus framework. We propose methodological considerations that should be included in such a framework and that can guide future studies. Furthermore, we highlight important points that should be addressed in future research to ensure compatibility between different dosimetry studies. Taken together, this review effort underlines the importance of a systematic approach to light-dosimetry in order to harness all the power of integrative lighting research in real-life.

Archaeoparasitology — a new source of reconstruction of migrations of ancient populations: opportunities, results, and prospects

The resilience of intestinal parasite ova to harsh environmental conditions and possibility of identification of many of them down to genus/species with the aid of conventional visual light microscopy make parasites an im-portant source of information on different aspects of life of ancient populations. Of special interest is the study of the phenomenon of parasitoidism aimed at reconstruction of ancient human migrations. Ectoparasites (the head louse) and a range of intestinal parasites of such groups as the helminths, tapeworms, and trematodes can be used as a marker of contacts and/or migration of people. Finding helminth ova in ancient samples collected in territories outside the endemic pockets can be direct evidence of contacts and/or migrations of the ancient popu-lation. An example of reconstruction of such migrations is given by, for instance, finding ova of the ascarids and whipworm on the territories of the Far North, mountainous Altai, deserts of the Central Asia etc. A remarkable example of migrations, according to the archaeoparasitology data, is the use of the helminths as a marker of an-cient human migrations, with the example of population of the American continent. It is noteworthy that almost a century old archaeoparasitology data find confirmation in the results of modern paleogenetic studies. In the recent decades, there have been review publications concerned with the finds of ova of various parasitic organisms in archaeological sites, many of which consolidated archaeoparasitology materials dealing with specific intestinal parasites, the impact of the parasites on the human evolution and their (viz., parasites and human) coevolution, and spread of the parasitic diseases as a result of climate changes both in ancient and modern times. All the works, without exception, emphasize the importance of archaeoparasitology data for the deeper understanding of these processes. However, although the first works on the reconstruction of migrations from parasitological data were published back in the beginning of the last century, the research works substantiating this approach and demonstrating its viability appeared only early in this century and elucidated biological pre-requisites for the re-construction of migrations. Therefore, new broad consolidation of the materials on the reconstruction of migrations from the data of archaeoparasitology is motivated not only by the need of reconsideration of already existing and new data, but also by the need of examination and verification of the archaeoparasitology facts in the context of the genetic data, archaeology, anthropology etc.

Measurement of Circadian Effectiveness in Lighting for Office Applications

As one factor among others, circadian effectiveness depends on the spatial light distribution of the prevalent lighting conditions. In a typical office context focusing on computer work, the light that is experienced by the office workers is usually composed of a direct component emitted by the room luminaires and the computer monitors as well as by an indirect component reflected from the walls, surfaces, and ceiling. Due to this multi-directional light pattern, spatially resolved light measurements are required for an adequate prediction of non-visual light-induced effects. In this work, we therefore propose a novel methodological framework for spatially resolved light measurements that allows for an estimate of the circadian effectiveness of a lighting situation for variable field of view (FOV) definitions. Results of exemplary in-field office light measurements are reported and compared to those obtained from standard spectral radiometry to validate the accuracy of the proposed approach. The corresponding relative error is found to be of the order of 3–6%, which denotes an acceptable range for most practical applications. In addition, the impact of different FOVs as well as non-zero measurement angles will be investigated.

Pain and its management: Dante’s Divine Comedy

Dante Alighieri died in 1321; therefore, 2021 is the 700th anniversary of his death. His best known work is the Divine Comedy, which explores Dante’s journey through the three realms of the underworld. Each realm is associated with three different sensations: Inferno, bodily (pain); Purgatorio, acoustic (music); and Paradiso, visual (light). The progression of the painful experiences and the resolution through music and light mirror the modern understanding of pain and its management. Music has both direct and indirect benefits and can help with coping. Sunlight promotes well-being and self-awareness.

Conceptual Design of an Anti-collision System for Light Rail Vehicles

This paper presents the concepts for an anti-collision system intended for trams. The purpose of the anti-collision system is to develop and provide information to support the driver’s decision to initiate the braking of a tram. The anti-collision system is based on the processing of data from multiple sources (obstacle detection, image processing, and visual light communication system) and an expert system. The information about the road situation is visually presented on HUD (Head-up Display) of the driver.

Beyond colour gamuts: Novel metrics for the reproduction of photoreceptor signals

Colour gamuts describe the chromaticity reproduction capabilities of a display, i.e. its ability to reproduce the relative cone excitations from real-world radiance spectra. While the cones dominate “canonical” visual function (i.e. perception of colour, space, and motion) under photopic light levels, they are not the only photoreceptors in the human retina. Rods and melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs) also respond to light and contribute to both visual and non-visual light responses, including circadian rhythms, sleep-wake control, mood, pupil size, and alertness. Three-primary display technologies, with their focus on reproducing colour, are not designed to reproduce the rod and melanopsin excitations. Moreover, conventional display metrics used to characterize three-primary displays fail to describe the display’s ability (or inability) to reproduce rod and melanopsin excitations, and thus do not capture the display’s ability to reproduce the full human physiological response to light. In this paper, three novel physiologically relevant metrics are proposed for quantifying the reproduction and distortion of the photoreceptor signals by visual displays. A novel equal-luminance photoreceptor excitation diagram is proposed, extending the well-known MacLeod-Boynton chromaticity diagram, to allow visualizations of the five-dimensional photoreceptor signal space in a three-dimensional projection.

Visual light perceptions caused by medical linear accelerator: Findings of machine-learning algorithms in a prospective questionnaire-based case–control study

This study aimed to investigate the possible incidence of visual light perceptions (VLPs) during radiation therapy (RT). We analyzed whether VLPs could be affected by differences in the radiation energy, prescription doses, age, sex, or RT locations, and whether all VLPs were caused by radiation. From November 2016 to August 2018, a total of 101 patients who underwent head-and-neck or brain RT were screened. After receiving RT, questionnaires were completed, and the subjects were interviewed. Random forests (RF), a tree-based machine learning algorithm, and logistic regression (LR) analyses were compared by the area under the curve (AUC), and the algorithm that achieved the highest AUC was selected. The dataset sample was based on treatment with non-human units, and a total of 293 treatment fields from 78 patients were analyzed. VLPs were detected only in 122 of the 293 exposure portals (40.16%). The dataset was randomly divided into 80% and 20% as the training set and test set, respectively. In the test set, RF achieved an AUC of 0.888, whereas LR achieved an AUC of 0.773. In this study, the retina fraction dose was the most important continuous variable and had a positive effect on VLP. Age was the most important categorical variable. In conclusion, the visual light perception phenomenon by the human body during RT is induced by radiation rather than being a self-suggested hallucination or induced by phosphenes.

Segmentation Approaches for Diabetic Foot Disorders

Thermography enables non-invasive, accessible, and easily repeated foot temperature measurements for diabetic patients, promoting early detection and regular monitoring protocols, that limit the incidence of disabling conditions associated with diabetic foot disorders. The establishment of this application into standard diabetic care protocols requires to overcome technical issues, particularly the foot sole segmentation. In this work we implemented and evaluated several segmentation approaches which include conventional and Deep Learning methods. Multimodal images, constituted by registered visual-light, infrared and depth images, were acquired for 37 healthy subjects. The segmentation methods explored were based on both visual-light as well as infrared images, and optimization was achieved using the spatial information provided by the depth images. Furthermore, a ground truth was established from the manual segmentation performed by two independent researchers. Overall, the performance level of all the implemented approaches was satisfactory. Although the best performance, in terms of spatial overlap, accuracy, and precision, was found for the Skin and U-Net approaches optimized by the spatial information. However, the robustness of the U-Net approach is preferred.