Enhanced Computational Imaging for Microendoscopy

Microendoscope imaging systems suffer from high levels of aberrations, a narrow Field of View and short Depth of Field. We present a technique for enhanced imaging through a microendoscope using a novel computational imaging approach

Time-sequential Pipelined Imaging with Wavefront Coding and Super Resolution

Wavefront coding has long offered the prospect of mitigating optical aberrations and extended depth of field, but image quality and noise performance are inevitably reduced. We report on progress in the use of agile encoding and pipelined fusion of image sequences to recover image quality

Entropy Production Associated with Aggregation into Granules in a Subdiffusive Environment

We study the entropy production that is associated with the growing or shrinking of a small granule in, for instance, a colloidal suspension or in an aggregating polymer chain. A granule will fluctuate in size when the energy of binding is comparable to kBT , which is the “quantum� of Brownian energy. Especially for polymers, the conformational energy landscape is often rough and has been commonly modeled as being self-similar in its structure. The subdiffusion that emerges in such a high-dimensional, fractal environment leads to a Fokker–Planck Equation with a fractional time derivative. We set up such a so-called fractional Fokker–Planck Equation for the aggregation into granules. From that Fokker–Planck Equation, we derive an expression for the entropy production of a growing granul

Three-level filter for increased depth of focus and Bessel beam generation

Author Posting. © Optical Society of America, 2012. This article is posted here by permission of Optical Society of America for personal use, not for redistribution. The definitive version was published in Optics Express 20 (2012): 27212-27221, doi:10.1364/OE.20.25.027212.A novel axially-symmetric filter for increasing focal depth and generating an approximation to a Bessel beam is proposed. It consists of an array of rings of strength –1,0 and 1. The design is based on an analytic solution, and combines high resolution in the transverse direction with good efficiency. One presented design increases the depth of focus compared with a standard lens by more than 30 times, with a very flat axial intensity distribution over this range. Effects of discretization are discussed. Various different approaches to increasing depth of focus are compared, to put the new design into perspective.Support from the Singapore-MIT Alliance for Research and Technology (SMART) Program is acknowledged. SM acknowledges a post-doctoral fellowship from Human Frontier Science Program (HFSP)

The System of Long-Term Care in Poland

In the field of social protection, Poland belongs to the EU group of countries with the familybased welfare model, what is extremely visible for the long-term care where family is the main care provider for elderly individuals with limitations in activities of daily living. At the same time the proportion of elderly in the coming decades is projected to be among the highest in the European Union, what raises questions on the design of the long-term care. For the moment the system is highly unregulated and disintegrated between social assistance and health care services. But it is the health sector that concentrates policy debate with a proposal of an introduction of nursing insurance. In the social sector, the significant changes that were favorable to LTC services development were introduced by the law on the social assistance (2004) and family benefits (2003) widening the scope of care available at home and in adult day care centers. But still provision of services is insufficient and a market of private services, paid out-of-pocket rapidly develops. It seems that main problems of the long-term care development in the future will be raising demand against insufficient resources and diversified priorities of the health care system

Experimental demonstration of extended depth-of-field f/1.2f/1.2 visible High Definition camera with jointly optimized phase mask and real-time digital processing

International audienceIncreasing the depth of field (DOF) of compact visible high resolution cameras while maintaining high imaging performance in the DOF range is crucial for such applications as night vision goggles or industrial inspection. In this paper, we present the end-to-end design and experimental validation of an extended depth-of-field visible High Definition camera with a very small f-number, combining a six-ring pyramidal phase mask in the aperture stop of the lens with a digital deconvolution. The phase mask and the deconvolution algorithm are jointly optimized during the design step so as to maximize the quality of the deconvolved image over the DOF range. The deconvolution processing is implemented in real-time on a Field-Programmable Gate Array and we show that it requires very low power consumption. By mean of MTF measurements and imaging experiments we experimentally characterize the performance of both cameras with and without phase mask and thereby demonstrate a significant increase in depth of field of a factor 2.5, as it was expected in the design step

A multi-modal stereo microscope based on a spatial light modulator

Spatial Light Modulators (SLMs) can emulate the classic microscopy techniques, including differential interference (DIC) contrast and (spiral) phase contrast. Their programmability entails the benefit of flexibility or the option to multiplex images, for single-shot quantitative imaging or for simultaneous multi-plane imaging (depth-of-field multiplexing). We report the development of a microscope sharing many of the previously demonstrated capabilities, within a holographic implementation of a stereo microscope. Furthermore, we use the SLM to combine stereo microscopy with a refocusing filter and with a darkfield filter. The instrument is built around a custom inverted microscope and equipped with an SLM which gives various imaging modes laterally displaced on the same camera chip. In addition, there is a wide angle camera for visualisation of a larger region of the sample