Large Scale Optical Projection Tomography without the Use of Refractive-Index-Matching Liquid.

The practical, rapid, and accurate optical 3D reconstruction of transparent objects with contemporary non-contact optical techniques, has been an open challenge in the field of optical metrology. The combination of refraction, reflection, and transmission in transparent objects makes it very hard to use common off-the-shelf 3D reconstruction solutions to accurately reconstruct transparent objects in three dimensions without completely coating the object with an opaque material. We demonstrate in this work that a specific class of transparent objects can indeed be reconstructed without the use of opaque spray coatings, via Optical Projection Tomography (OPT).

Highly sensitive resistance spectroscopy technique for online monitoring of biofilm growth on metallic surfaces.

Online techniques for monitoring biofilm formation and evolution are limited, especially as regards its application in flowing water systems. This is chiefly due to the absence of efficient non-destructive and non-invasive sensing methods. In this study, a sensitive electrical resistance spectroscopy technique is developed to monitor non-invasively and in real time the growth of biofilms over metallic surfaces inside water flow systems.

Relationship of 24-h ambulatory blood pressure variability with micro and macrovascular parameters and hypertension status.

Objectives: Increased blood pressure variability (BPV) has been associated with an increased risk of subclinical organ damage and cardiovascular events, independently of elevated average BP values. We aimed to investigate the association of BPV indices with micro- and macrovascular parameters, some of them not previously studied.

Methods: We evaluated 344 individuals (233 never-treated/newly diagnosed hypertensive and 111 normotensive individuals).

Bubble growth analysis during subcooled boiling experiments on-board the international space station: Benchmark image analysis.

This work compares four different image processing algorithms for the analysis of image data obtained during the Multiscale Boiling Experiment of ESA, executed on-board the International Space Station. Two separate experimental campaigns have been performed in 2019 and 2020, aiming to investigate boiling phenomena in microgravity, with and without the presence of shear flow and electric field. A heated substrate, at the bottom of the test cell, creates a temperature profile across the liquid bulk above it.

Monitoring Health Parameters of Elders to Support Independent Living and Improve Their Quality of Life.

Improving the well-being and quality of life of the elderly population is closely related to assisting them to effectively manage age-related conditions such as chronic illnesses and anxiety, and to maintain their independence and self-sufficiency as much as possible. This paper presents the design, architecture and implementation structure of an adaptive system for monitoring the health and well-being of the elderly. The system was designed following best practices of the Human-Centred Design approach involving representative end-users from the early stages.

Retinal image registration as a tool for supporting clinical applications.

Background And Objective: The study of small vessels allows for the analysis and diagnosis of diseases with strong vasculopathy. This type of vessels can be observed non-invasively in the retina via fundoscopy. The analysis of these vessels can be facilitated by applications built upon Retinal Image Registration (RIR), such as mosaicing, Super Resolution (SR) or eye shape estimation.

REMPE: Registration of Retinal Images Through Eye Modelling and Pose Estimation.

Objective: In-vivo assessment of small vessels can promote accurate diagnosis and monitoring of diseases related to vasculopathy, such as hypertension and diabetes. The eye provides a unique, open, and accessible window for directly imaging small vessels in the retina with non-invasive techniques, such as fundoscopy. In this context, accurate registration of retinal images is of paramount importance in the comparison of vessel measurements from original and follow-up examinations, which is required for monitoring the disease and its treatment.

Association of Urinary Sodium Excretion with Vascular Damage: A Local Kidney Effect, Rather Than a Marker of Generalized Vascular Impairment.

Evidence suggests that increased salt consumption induces blood pressure- (BP) mediated organ damage, yet it remains unclear whether it reflects a generalized micro- and macrovascular malfunction independent of BP. We studied 197 newly diagnosed and never-treated individuals with hypertension, intermediate hypertensive phenotypes, and normal BP, classified by use of 24-hour ambulatory BP monitoring. Sodium excretion and microalbuminuria were estimated in 24-hour urine samples, dermal capillary density was estimated from capillaroscopy, and arterial stiffness was estimated with pulse wave velocity (PWV) and augmentation index (AIx).

Urinary albumin excretion in rheumatoid arthritis is not associated with markers of vasculopathy in distal microvascular beds.

Objective: Increased UAE is a marker of generalized vascular damage in high-cardiovascular risk patients. However, it remains unknown whether it corresponds to a state of diffuse vasculopathy in high-risk patients with RA.

Methods: UAE was estimated in 24-hour urine samples in RA and non-RA individuals.

Dermal capillary rarefaction as a marker of microvascular damage in patients with rheumatoid arthritis: Association with inflammation and disorders of the macrocirculation.

Objective: Capillary rarefaction is observed in various cardiovascular diseases, yet it remains understudied in RA, a chronic inflammatory disease accompanied by excess cardiovascular risk. We quantified capillary density in RA patients and explored potential associations with macrocirculatory disorders, inflammation, and cardiovascular risk.

Methods: Dermal capillary density was assessed with nailfold capillaroscopy in RA and non-RA individuals, using specifically designed semiautomated software.

An experimental evaluation of the accuracy of keypoints-based retinal image registration.

This work regards an investigation of the accuracy of a state-of-the-art, keypoint-based retinal image registration approach, as to the type of keypoint features used to guide the registration process. The employed registration approach is a local method that incorporates the notion of a 3D retinal surface imaged from different viewpoints and has been shown, experimentally, to be more accurate than competing approaches. The correspondences obtained between SIFT, SURF, Harris-PIIFD and vessel bifurcations are studied, either individually or in combinations.

Retinal vessel morphology in rheumatoid arthritis: Association with systemic inflammation, subclinical atherosclerosis, and cardiovascular risk.

Objective: Quantification of retinal vessel morphology has emerged as a marker of cardiovascular health. We examined retinal microvascular diameters in RA, particularly in regard to systemic inflammation, subclinical atherosclerosis, and cardiovascular risk.

Methods: Retinal images from RA patients and controls were processed using computerized software, to obtain CRAE and CRVE and AVR.

Retinal image registration through simultaneous camera pose and eye shape estimation.

In this paper, a retinal image registration method is proposed. The approach utilizes keypoint correspondences and assumes that the human eye has a spherical or ellipsoidal shape. The image registration problem amounts to solving a camera 3D pose estimation problem and, simultaneously, an eye 3D shape estimation problem.

Retinal image registration under the assumption of a spherical eye.

We propose a method for registering a pair of retinal images. The proposed approach employs point correspondences and assumes that the human eye has a spherical shape. The image registration problem is formulated as a 3D pose estimation problem, solved by estimating the rigid transformation that relates the views from which the two images were acquired.

Impaired metabolic profile is a predictor of capillary rarefaction in a population of hypertensive and normotensive individuals.

Capillary rarefaction is typically encountered in essential hypertension, yet identification of factors interfering with this phenomenon remains substantially underinvestigated. We examined whether components of metabolic profile (dyslipidemia, insulin resistance), inflammatory (high-sensitivity C-reactive protein, high-sensitivity C-reactive protein), and angiogenic (vascular endothelial growth factor) factors are implicated in this phenomenon in a population of newly diagnosed, never-treated hypertensive patients and normotensive controls. Nailfold capillary density was estimated with nailfold capillaroscopy using specifically designed software.

Retinal image registration based on keypoint correspondences, spherical eye modeling and camera pose estimation.

In this work, an image registration method for two retinal images is proposed. The proposed method utilizes keypoint correspondences and assumes a spherical model of the eye. Image registration is treated as a pose estimation problem, which requires estimation of the rigid transformation that relates the two images.

In vivo analysis of the time and spatial activation pattern of microglia in the retina following laser-induced choroidal neovascularization.

Microglia play a major role in retinal neovascularization and degeneration and are thus potential targets for therapeutic intervention. In vivo assessment of microglia behavior in disease models can provide important information to understand patho-mechanisms and develop therapeutic strategies. Although scanning laser ophthalmoscope (SLO) permits the monitoring of microglia in transgenic mice with microglia-specific GFP expression, there are fundamental limitations in reliable identification and quantification of activated cells.

Super resolution for fundoscopy based on 3D image registration.

An approach to the generation of super-resolution (SR) images from fundoscopy images is proposed that is based on the 3D registration of the original fundoscopy images. The proposed approach utilizes a simple 3D registration method to enable the application of conventional SR techniques which, otherwise, employ 2D image registration. Qualitative and quantitative comparative evaluation shows that the obtained results improve image definition and alleviate noise.

Accumulation of microvascular target organ damage in newly diagnosed hypertensive patients.

Early identification of hypertensive target organ damage (TOD) emerges as important for global cardiovascular risk assessment. Retinal vascular alterations, capillary rarefaction, and microalbuminuria represent different forms of microvascular TOD. However, data regarding their concomitant presence in the early stages of hypertension, the association of the number of affected organs with cardiovascular risk, and aldosterone effect on multiple TOD are lacking.

Association between retinal vessel caliber and arterial stiffness in a population comprised of normotensive to early-stage hypertensive individuals.

Background: Although impairment of the micro- and macrocirculation is considered inherent to sustained hypertension, there is a substantial lack of studies investigating whether an association exists between micro- and macrovascular damage, especially in early-stage hypertension.

Methods: We studied a meticulously selected population, free of diabetes and cardiovascular disease, of 223 individuals: 137 never-treated, newly diagnosed patients with recent onset of hypertension and 86 normotensive individuals. Nonmydriatic retinal photography was used to assess retinal microvascular diameters, including central retinal arteriolar (CRAE) and venular equivalent and arteriovenous ratio (AVR).

Divergent retinal vascular abnormalities in normotensive persons and patients with never-treated, masked, white coat hypertension.

Background: Hypertensive patients with retinal arteriolar abnormalities are at increased risk for cardiovascular events. However, the extent of retinal microvascular changes in naïve, never-treated patients with hypertension of short duration has not been established. In addition to this, the lack of relevant data about other phenotypes of hypertension (masked and white-coat hypertension) determined by ambulatory blood-pressure measurement (ABPM) is notable, despite their relationship to increased cardiovascular risk mediated by underlying target-organ and vascular damage.

Development of a three-dimensional surface imaging system for melanocytic skin lesion evaluation.

Even though surface morphology is always taken into account when assessing clinically pigmented skin lesions, it is not captured by most modern imaging systems using digital imaging. Our aim is to develop a novel three-dimensional (3D) imaging technique to record detailed information of the surface anatomy of melanocytic lesions that will enable improved classification through digital imaging. The apparatus consists of three high-resolution cameras, a light source, and accompanying software.

Effects of vibratory actuation on endoscopic capsule vision.

Current research in capsule endoscopy aims at endowing the capsules with some means of actively propelling themselves inside the gastrointestinal (GO tract, as opposed Advantages of these active capsules are the sipificant potential in the duration of the associated diagnostic procedures. as well as the oossihilitv to direct the line-of-sieht of the oh-hoard cameras towards interesting features of the GI tissue. One such means of active propulsion is by vibratory actuation, employing eccentric-mass micromotors, which is shown to reduce the friction of the capsule with the GI tract.

Starry night: a texture devoid of depth cues.

From a modern Bayesian point of view, the classic Julesz random-dot stereogram is a cue-conflict stimulus: Texture cues specify an unbroken, unslanted surface, in conflict with any variation in depth specified by binocular disparity. We introduce a new visual texture-the starry night texture (SNT)--that is incapable of conveying slant, depth edges, or texture boundaries, in a single view. For SNT, changing density is equivalent to changing intensity, so an instance of the texture is characterized (up to the random locations of the texture elements) by what we call its densintensity.

WebOnCOLL: medical collaboration in regional healthcare networks.

This paper presents WebOnCOLL, a web-based medical collaboration environment, which has been designed in the context of the regional healthcare network of Crete. WebOnCOLL employs the infrastructure of regional healthcare networks to provide integrated services for virtual workspaces, annotations, e-mail, and on-line collaboration. Virtual workspaces support collaborative concepts like personal web pages, bulletin boards, discussion lists, shared workspaces, and medical case folders.