Optical devices

It is a widely accepted belief in clinical practice that children with a visual impairment can profit from the use of a low vision aid (LVA). However, we found a considerable gap in our scientific understanding of LVA use, particularly in young children. This is the reason for the analysis presented in this paper. A selected overview of LVA use in adults is given, from which valuable insights are taken. Additionally, an action perspective for analysing LVA use is discussed as well as the results of tool-use studies in children. Mainly based on these three ingredients, we developed a conceptual framework for LVA use. The framework consists of three interacting relations between LVA, child and task. Performance of a particular child on a specific task with a certain LVA is constrained by the following three reciprocal and dynamic relations: the Child-to-Task relation (related to goal-information), the Child-to-LVA relation (related to control-information), and the LVA-to-Task relation (related to topology information).► Both definition and performance of a task change critically when using a LVA. ► LVAs change properties and possibilities of attached perception and action systems. ► Performance with LVA is shaped by the relations between LVA, user, and task. ► Research on the developing interrelations in the LVA-Child-Task system is needed.

Bite mark analysis offers the opportunity to identify the biter based on the individual characteristics of the dentitions. Normally, the main focus is on analysing bite mark injuries on human bodies, but also, bite marks in food may play an important role in the forensic investigation of a crime. This study presents a comparison of simulated bite marks in different kinds of food with the dentitions of the presumed biter. Bite marks were produced by six adults in slices of buttered bread, apples, different kinds of Swiss chocolate and Swiss cheese. The time-lapse influence of the bite mark in food, under room temperature conditions, was also examined. For the documentation of the bite marks and the dentitions of the biters, 3D optical surface scanning technology was used. The comparison was performed using two different software packages: the ATOS modelling and analysing software and the 3D studio max animation software. The ATOS software enables an automatic computation of the deviation between the two meshes. In the present study, the bite marks and the dentitions were compared, as well as the meshes of each bite mark which were recorded in the different stages of time lapse. In the 3D studio max software, the act of biting was animated to compare the dentitions with the bite mark. The examined food recorded the individual characteristics of the dentitions very well. In all cases, the biter could be identified, and the dentitions of the other presumed biters could be excluded. The influence of the time lapse on the food depends on the kind of food and is shown on the diagrams. However, the identification of the biter could still be performed after a period of time, based on the recorded individual characteristics of the dentitions.

La caja óptica, como parte de la cultura del entretenimiento durante los siglos XVIII y XIX, fue concebida en sus distintas versiones como medio para la visualización de vistas bidimensionales.
El presente artículo explica el proceso de concepción y elaboración de un dispositivo que pretende continuar con la evolución de este aparato materializando una de sus variantes técnico-conceptual de la cual no hay constancia documental de su desarrollo en su época; así, es ahora rediseñada como visor de objetos tridimensionales utilizando, en ese proceso, los principios de la arqueología de los medios como disciplina o metodología de análisis teórico-práctico.
Por una parte, desde la puesta en valor de la experiencia del espectador, en tanto que tecnológica y culturalmente estructurada por los medios; por otra, desde la consideración del diseño y la materialización de dispositivos, de la práctica, como metodología de investigación.
Por último, desde la utilización de técnicas obsoletas como medio de enfatizar sus valores estéticos, utilizarlos con nuevos usos o materializar posibles vías de evolución no desarrolladas.
Desde esta voluntad de rescatar y valorar las cualidades genuinas de un dispositivo obsoleto, pero innovador de un modo anacrónico, surge el Visor de dioramas con enfoque selectivo.
El Visor de dioramas con enfoque selectivo es un dispositivo óptico, dotado de lente, para la presentación y visualización de dioramas, maquetas a escala u otros objetos. Mediante dicho dispositivo el espectador puede modular la profundidad de campo, regulando la distancia entre la lente y el diorama, enfocando y desenfocando los distintos planos en los que están dispuestos los elementos ubicados en su interior.

This article presents a novel approach for vision-based detection and tracking of humans wearing high-visibility clothing with retro-reflective markers. Addressing industrial applications where heavy vehicles operate in the vicinity of humans, we deploy a customized stereo camera setup with active illumination that allows for efficient detection of the reflective patterns created by the worker's safety garments. After segmenting reflective objects from the image background, the interest regions are described with local image feature descriptors and classified in order to discriminate safety garments from other reflective objects in the scene. In a final step, the trajectories of the detected humans are estimated in 3D space relative to the camera. We evaluate our tracking system in two industrial real-world work environments on several challenging video sequences. The experimental results indicate accurate tracking performance and good robustness towards partial occlusions, body...

Real-time measurements of biological/chemical/physical processes, with no interferences, are an ultimate goal for in vivo intracellular studies. To construct intracellular biosensors that meet such a goal, nanoparticle (NP) platforms seem to be most promising, because of their small size and excellent engineerability. This review describes the development of NP-based opical sensors and their intracellular applications. The sensor designs are classified into two types, based on the sensor structures regarding analyte receptor and signal transducer. Type 1 sensors, with a single component for both receptor and transducer, work by mechanisms similar to those of 'molecular probes'. Type 2 sensors, with a separate component for receptor and transducer, work by different mechanisms that require the presence of specific NPs. A synergistic increase in optical signal or selectivity has been reported for these second type of NP sensors. With ongoing rapid advances in nanotechnology an...

The domestic market for home-use hair removal devices is rapidly expanding and there are numerous intense pulsed light (IPL) products now available globally to consumers. Technological challenges for the design of such devices include the need to be cost-effective in mass production, easy to use without training, and most importantly, clinically effective while being eye-safe. However inexpensively these light-based systems are produced, they are designed to cause biological damage to follicular structures, so precautions to prevent both ocular and epidermal damage must be considered. At present, there are no dedicated international standards for IPL devices. This review directly compares three leading domestic IPL hair removal devices: iPulse Personal (CyDen, UK), Silk'n/SensEpil (Home Skinovations, Israel), and SatinLux/Lumea (Philips, Netherlands) for fluence, emitted wavelength spectrum, time-resolved footprint, and spatial distribution of energy. Although each device has a primary mechanical or electrical safety feature to ensure occlusion of the output aperture on the skin to prevent accidental eye exposure, the ocular hazard of each device has been measured to IEC TR 60825-9 standard using an Ocean Optics HR2000+ photo spectrometer for both potential corneal and retinal damage. Using established measurement methods, this review has shown that the measured output parameters were significantly different for the three systems. Using equipment traceable to national standards, one device was judged at its two highest settings to be hazardous for naked eye viewing. This investigation also reports on the significantly different pulse durations of the devices measured and considers the potential impact on safety and efficacy in the light of the theory of selective photothermolysis. Although these devices offer low-cost personal convenience of treatment in the privacy of the home, ocular safety may be inadequate in the event of primary safety mechanism failure.

This paper presents an enhanced haptic-enabled master-slave teleoperation system which can be used to provide force feedback to surgeons in minimally invasive surgery (MIS). One of the research goals was to develop a combined-control architecture framework that included both direct force reflection (DFR) and position-error-based (PEB) control strategies. To achieve this goal, it was essential to measure accurately the direct contact forces between deformable bodies and a robotic tool tip. To measure the forces at a surgical tool tip and enhance the performance of the teleoperation system, an optical force sensor was designed, prototyped, and added to a robot manipulator. The enhanced teleoperation architecture was formulated by developing mathematical models for the optical force sensor, the extended slave robot manipulator, and the combined-control strategy. Human factor studies were also conducted to (a) examine experimentally the performance of the enhanced teleoperation system w...

Inorganic light-emitting diodes and photodetectors represent important, established technologies for solid-state lighting, digital imaging and many other applications. Eliminating mechanical and geometrical design constraints imposed by the supporting semiconductor wafers can enable alternative uses in areas such as biomedicine and robotics. Here we describe systems that consist of arrays of interconnected, ultrathin inorganic light-emitting diodes and photodetectors configured in mechanically optimized layouts on unusual substrates. Light-emitting sutures, implantable sheets and illuminated plasmonic crystals that are compatible with complete immersion in biofluids illustrate the suitability of these technologies for use in biomedicine. Waterproof optical-proximity-sensor tapes capable of conformal integration on curved surfaces of gloves and thin, refractive-index monitors wrapped on tubing for intravenous delivery systems demonstrate possibilities in robotics and clinical medicine. These and related systems may create important, unconventional opportunities for optoelectronic devices.

This review investigates optical sensor platforms for protein multiplexing, the ability to analyze multiple analytes simultaneously. Multiplexing is becoming increasingly important for clinical needs because disease and therapeutic response often involve the interplay between a variety of complex biological networks encompassing multiple, rather than single, proteins. Multiplexing is generally achieved through one of two routes, either through spatial separation on a surface (different wells or spots) or with the use of unique identifiers/labels (such as spectral separation-different colored dyes, or unique beads-size or color). The strengths and weaknesses of conventional platforms such as immunoassays and new platforms involving protein arrays and lab-on-a-chip technology, including commercially-available devices, are discussed. Three major public health concerns are identified whereby detecting medically-relevant markers using Point-of-Care (POC) multiplex assays could potentiall...