Publications associées à Vectorial reconstruction of retinal blood flow in three dimensions measured with high resolution resonant Doppler Fourier domain optical coherence tomography

Design, computational and experimental investigation of a small-scale turbopump for organic Rankine cycle systems

Jürg Alexander Schiffmann, Sajjad Zakeralhoseini

The hydraulic design, computational analysis, and experimental investigations of a high-speed small-scale turbopump for mobile waste heat recovery applications based on organic Rankine cycle systems are presented in this paper. Such applications demand hig ...

Elsevier2023

The influence of splitter blades and meridional profiles on the performance of small-scale turbopumps for ORC applications; analysis, neural network modeling and optimization

Jürg Alexander Schiffmann, Sajjad Zakeralhoseini

This work presents the influence of splitters on the performance of small-scale turbopumps for organic Rankine cycle applications numerically. Different design parameters, such as impeller diameter at the outlet, number of blades, blade angle at the traili ...

2023

Cardiovascular monitoring system

Marco Mattavelli, Catherine Dehollain, Diego Ruben Barrettino, Kerim Türe, Mustafa Besirli

A cardiovascular monitoring system for measuring at least cardiac output comprises an implantable unit (2) configured for placement in a section of artery of a patient and a portable external unit (1) configured for mounting against or close to a patient's ...

2022

Ultra-high voltage, low power and energy recovering electronics for dielectric elastomer actuators

Raphaël Johannes Charles Mottet

Heart failure is a cardiovascular disease affecting between 1 and 2% of the population of developed countries alone - more than 10 million people - with this number bound to increase due to the ageing of the population. This condition starts to develop its ...

EPFL2022

Model order reduction of flow based on a modular geometrical approximation of blood vessels

Simone Deparis, Luca Pegolotti

We are interested in a reduced order method for the efficient simulation of blood flow in arteries. The blood dynamics is modeled by means of the incompressible Navier–Stokes equations. Our algorithm is based on an approximated domain-decomposition of the ...

2021

Computational Analysis of Turbulent Hemodynamics in Radiocephalic Arteriovenous Fistulas to Determine the Best Anastomotic Angles

Alfio Quarteroni, Christian Vergara

Background: Hemodynamics has been known to play a major role in the development of intimal hyperplasia leading to arteriovenous fistula failure. The goal of our study is to investigate the influence of different angles of side-to-end radiocephalic anastomo ...

ELSEVIER SCIENCE INC2020

Graph-based regularization of inverse problems in imaging

Mattia Rossi

As of today, the extension of the human visual capabilities to machines remains both a cornerstone and an open challenge in the attempt to develop intelligent systems. On the one hand, the development of more and more sophisticated imaging devices, capable ...

EPFL2020

Optical phase contrast imaging of human retinal cells by changing the tissue refractive index

Christophe Moser, Mathieu Künzi, Timothé Laforest, Laura Emmanuelle Kowalczuk

Purpose : Based on oblique partially coherent illumination of transparent samples, we developed a simple custom Optical Phase Imaging (OPI) microscope providing a label-free, semi-quantitative phase contrast imaging. The aim of this study was to explore th ...

ASSOC RESEARCH VISION OPHTHALMOLOGY INC2020

Analysis of morphological and haemodynamical indexes in abdominal aortic aneurysms as preliminary indicators of intraluminal thrombus deposition

Alfio Quarteroni, Simone Deparis, Claudia Maria Colciago

In this paper we study the correlation between the Wall Shear Stress (WSS), a haemodynamical index derived from numerical simulations, and an new index MFA-ILT for the characterisation of intraluminal thrombus (ILT) in presence of abdominal aortic aneurysm ...

2020

Structural and functional brain imaging using extended-focus optical coherence tomography and microscopy

Paul James Marchand

Neuroimaging techniques aim at revealing the anatomy and functional organisation of cerebral structures. Over the past decades, functional magnetic resonance imaging (fMRI) has revolutionized our understanding of human cerebral physiology through its abili ...

EPFL2018

Brain Perfusion Measurements Using Multidelay Arterial Spin-Labeling Are Systematically Biased by the Number of Delays

Dimitri Nestor Alice Van De Ville, Nicolas Gninenko, Merel Margaretha van der Thiel

BACKGROUND AND PURPOSE:Multidelay arterial spin-labeling is a promising emerging method in clinical practice. The effect of imaging parameters in multidelay arterial spin-labeling on estimated cerebral blood flow measurements remains unknown. We directly c ...

AMER SOC NEURORADIOLOGY2018

En face retinal imaging

Dino Carpentras

Retinal imaging is routinely used to provide information about vision health. Recent studies showed that retinal images can also provide information on general health (e.g. stress level), brain pathologies and attention. Depending on the target information ...

EPFL2018

System, method and apparatus for retinal absorption phase and dark field imaging with oblique illumination

Christophe Moser, Mathieu Künzi, Dino Carpentras, Timothé Laforest

A method for imaging a tissue of an eye, the method including the steps of providing oblique illumination to the eye by a plurality of light emitting areas of a light delivery device, the plurality of light emitting areas being independently controllable a ...

2017

A Monolithic Approach to Fluid–Composite Structure Interaction

Simone Deparis, Annalisa Quaini, Davide Forti

We study a nonlinear fluid–structure interaction (FSI) problem between an incompressible, viscous fluid and a composite elastic structure consisting of two layers: a thin layer (membrane) in direct contact with the fluid, and a thick layer (3D linearly ela ...

Springer Verlag2017

ORC Driven Heat Pump Running on Gas Bearings for Domestic Applications: Proof of Concept and Thermo-Economic Improvement Potential

Jürg Alexander Schiffmann, Violette Mounier

ORC driven Heat Pumps (HP-ORC) offer a promising technology of thermally driven heat pumps (TDHPs) for domestic applications. Recently, a 40 kW HP-ORC unit based on gas supported turbomachinery has been investigated in which the ORC radial turbine drives t ...

2017

The Role of Impeller Outflow Conditions on the Performance of Vaned Diffusers

Jürg Alexander Schiffmann

Highly loaded impellers, typically used in turbocharger and gas turbine applications, exhaust an unsteady, transonic flow that is nonuniform across the span and pitch and swirling at angles approaching tangential. With the exception of the flow angle, conf ...

American Society of Mechanical Engineers2017

Pitfalls Of Doppler Measurements For Arterial Blood Flow Quantification In Small Animal Research: A Study Based On Virtual Ultrasound Imaging

Patrick Segers, Bram Trachet

High-resolution Doppler is a popular tool for evaluating cardiovascular physiology in mutant mice, though its 1-D nature and spectral broadening processes complicate interpretation of the measurement. Hence, it is crucial for pre-clinical researchers to kn ...

Elsevier2016

Methods for reliable estimation of pulse transit time and blood pressure variations using smartphone sensors

David Atienza Alonso, Srinivasan Murali, Francisco Javier Rincon Vallejos, Alair Dias Junior

Hypertension is known to affect around one third of adults globally and early diagnosis is essential to reduce the effects of this affliction. Today’s Blood Pressure (BP) monitoring cuffs are obtrusive and in- convenient for performing regular measurements ...

Elsevier Science Bv2016

Sampling Models in Light Fields

Zhou Xue

What is the actual information contained in light rays filling the 3-D world? Leonardo da Vinci saw the world as an infinite number of radiant pyramids caused by the objects located in it. Nowadays, the radiant pyramid is usually described as a set of ligh ...

EPFL2016

Visualization of hepatic arteries with 3D ultrasound during intra-arterial therapies

Alexandre Bigot, François Michaud, Anaïs Laure Marie-Thérèse Badoual

Liver cancer represents the second most common cause of cancer-related mortality worldwide. The prognosis is poor with an overall mortality of 95%. Moreover, most hepatic tumors are unresectable due to their advanced stage at discovery or poor underlying l ...

Spie-Int Soc Optical Engineering2016