The challenge of dry eye diagnosis

The currently available methods for the diagnosis of dry eye are still far from being perfect for a variety of reasons. This review attempts to highlight the advantages and disadvantages of both traditional tests (such as Schirmer’s test, break-up time and ocular surface staining) and innovative noninvasive procedures, including tear meniscus height measurement, corneal topography, functional visual acuity, tear interferometry, tear evaporimetry and tear osmolarity assessment

Technological enhancements to optometric clinical tests

A sizeable amount of the testing in eye care, requires either the identification of targets such as letters to assess functional vision, or the subjective evaluation of imagery by an examiner. Computers can render a variety of different targets on their monitors and can be used to store and analyse ophthalmic images. However, existing computing hardware tends to be large, screen resolutions are often too low, and objective assessments of ophthalmic images unreliable. Recent advances in mobile computing hardware and computer-vision systems can be used to enhance clinical testing in optometry. High resolution touch screens embedded in mobile devices, can render targets at a wide variety of distances and can be used to record and respond to patient responses, automating testing methods. This has opened up new opportunities in computerised near vision testing. Equally, new image processing techniques can be used to increase the validity and reliability of objective computer vision systems. Three novel apps for assessing reading speed, contrast sensitivity and amplitude of accommodation were created by the author to demonstrate the potential of mobile computing to enhance clinical measurement. The reading speed app could present sentences effectively, control illumination and automate the testing procedure for reading speed assessment. Meanwhile the contrast sensitivity app made use of a bit stealing technique and swept frequency target, to rapidly assess a patient’s full contrast sensitivity function at both near and far distances. Finally, customised electronic hardware was created and interfaced to an app on a smartphone device to allow free space amplitude of accommodation measurement. A new geometrical model of the tear film and a ray tracing simulation of a Placido disc topographer were produced to provide insights on the effect of tear film breakdown on ophthalmic images. Furthermore, a new computer vision system, that used a novel eye-lash segmentation technique, was created to demonstrate the potential of computer vision systems for the clinical assessment of tear stability. Studies undertaken by the author to assess the validity and repeatability of the novel apps, found that their repeatability was comparable to, or better, than existing clinical methods for reading speed and contrast sensitivity assessment. Furthermore, the apps offered reduced examination times in comparison to their paper based equivalents. The reading speed and amplitude of accommodation apps correlated highly with existing methods of assessment supporting their validity. Their still remains questions over the validity of using a swept frequency sine-wave target to assess patient’s contrast sensitivity functions as no clinical test provides the range of spatial frequencies and contrasts, nor equivalent assessment at distance and near. A validation study of the new computer vision system found that the authors tear metric correlated better with existing subjective measures of tear film stability than those of a competing computer-vision system. However, repeatability was poor in comparison to the subjective measures due to eye lash interference. The new mobile apps, computer vision system, and studies outlined in this thesis provide further insight into the potential of applying mobile and image processing technology to enhance clinical testing by eye care professionals

Examining the taphonomic challenges to the 3D digitisation of fragmented bone

The utilisation of 3D digitisation and visualisation has grown considerably since 2008 and is becoming an increasingly useful tool for the digital documentation and metric analysis of archaeological artefacts and skeletal remains. It provides public access to rare and fragile specimens of palaeontological and palaeopathological importance whilst reducing the physical impact on these remains. Research in engineering and computer vision provides some insight into the impact of surface properties such as colour, specularity, reflectance and shape on the quality of the recorded 3D image, but within the archaeological and palaeontological disciplines comparable work has not yet been developed. If archaeology and anthropology are to provide long term reliable data from archaeological and palaeontological specimens in a way that doesn’t require repeated re-digitisation, we need to understand the impacts that the taphonomic histories of such samples have on our ability to 3D record them. Understanding the relationship of these taphonomic histories and the surface and optical properties will promote informed choices about the suitability of recording techniques. This thesis considers the taphonomic processes that affect the preservation of bone over archaeological, forensic and palaeontological timescales and the effect this has on the quality of 3D digital models. The digital refit of fragmentary bone samples is considered in relation to the effect of taphonomic alterations to bone. Conclusions regarding the key taphonomic factors and 3D digital model quality are drawn and areas of further work are identified.Arts and Humanities Research Counci

Polymer Materials in Biomedical Application

Recently, the development of polymeric materials for biomedical applications has advanced significantly. Polymeric materials are favored in the development of therapeutic devices, including temporary implants and three-dimensional scaffolds for tissue engineering and in vitro disease modelling.Further advancements have also occurred in the utilization of polymeric materials for pharmacological applications, such as delivery vehicles for drug release.We would like to invite you to contribute to this Special Issue. Research topics of interest include, but are not limited to, recent advances related to 3D cell culture, biomaterials, tissue engineering, disease modelling, hydrogel, organoids, drug discovery, bioimaging, cardio-renal, metabolic disease, and stem cell biology

Terahertz (THz) biophotonics technology : instrumentation, techniques, and biomedical applications

Terahertz (THz) technology has experienced rapid development in the past two decades. Growing numbers of interdisciplinary applications are emerging, including material science, physics, communications, security, as well as biomedicine. THz biophotonics involves studies applying THz photonic technology in biomedicine, which has attracted attention due to the unique features of THz waves, such as the high sensitivity to water, resonance with biomolecules, favourable spatial resolution, capacity to probe the water-biomolecule interactions and non-ionizing photon energy. Despite the great potential, THz biophotonics is still at an early stage of development. There is a lack of standards for instrumentation, measurement protocols, and data analysis which makes it difficult to make comparisons among all the work published. In this article we give a comprehensive review of the key findings which have underpinned research into biomedical applications of THz technology. In particular, we will focus on the advances made in general THz instrumentation and specific THz-based instruments for biomedical applications. We will also discuss the theories describing the interaction between THz light and biomedical samples. We aim to provide an overview of both, basic biomedical research, as well as pre-clinical and clinical applications under investigation. The paper aims to provide a clear picture of the achievements, challenges and future perspectives of THz biophotonics

Nanofabrication

We face many challenges in the 21st century, such as sustainably meeting the world's growing demand for energy and consumer goods. I believe that new developments in science and technology will help solve many of these problems. Nanofabrication is one of the keys to the development of novel materials, devices and systems. Precise control of nanomaterials, nanostructures, nanodevices and their performances is essential for future innovations in technology. The book "Nanofabrication" provides the latest research developments in nanofabrication of organic and inorganic materials, biomaterials and hybrid materials. I hope that "Nanofabrication" will contribute to creating a brighter future for the next generation

Investigating the effect detector geometry has on heterodyne to non-heterodyne signal ratio (HNHR) in a low-coherence tissue imaging interferometer

A Monte Carlo simulation is used to simulate the emergent light distribution from a turbid media sample placed in the probe beam arm of a scanning low-coherence interferometer that is used to build-up voxelated images in three-dimensions. The sample is a simple three-layered model with an embedded cylinder which simulates the physical and optical properties of skin for near-infrared light passing through the sample. Coherent light from an input probe beam of variable profile and incidence angle is traced through the sample by means of ray-tracing, and any emergent beams are collected in a sample surface array which also logs any emergent Monte Carlo generated photons reaching the surface. At the surface, the heterodyne to nonheterodyne signal ratio (HNHR) measured by a user-defined variable geometry detector is calculated for each point upon a linear scan of the detector position across the sample surface. A coherence gate is set to image a voxel located at the uppermost point of the blood vessel-simulating cylinder. Monte Carlo simulations are performed for various input probe beam angles and probe beam profiles, and the HNHR analysed for various detector geometries by varying: the detector area, central detector axis angle and the acceptance angle at the detector. The Monte Carlo results confirm the benefit of confocal detection, and indicate that angular decoupling of the light delivery and detection systems can improve differential HNHR measurements at scan extremities by 25 to 30 dB provided that stratum comeum is either removed or the sample index matched to the imaging system. Also presented is the description of a prototype experimental low-coherence interferometer system and some of the results derived from it: at its best this system was able to measure reflected coherent signals with a dynamic range approximating 130 dB

Articles indexats publicats per investigadors del Campus de Terrassa: 2013

Aquest informe recull els 228 treballs publicats per 177 investigadors/es del Campus de Terrassa en revistes indexades al Journal Citation Report durant el 2013Preprin

Technology 2001: The Second National Technology Transfer Conference and Exposition, volume 2

Proceedings of the workshop are presented. The mission of the conference was to transfer advanced technologies developed by the Federal government, its contractors, and other high-tech organizations to U.S. industries for their use in developing new or improved products and processes. Volume two presents papers on the following topics: materials science, robotics, test and measurement, advanced manufacturing, artificial intelligence, biotechnology, electronics, and software engineering

EUROSENSORS XVII : book of abstracts

Fundação Calouste Gulbenkien (FCG).Fundação para a Ciência e a Tecnologia (FCT)