Centre National De La Recherche Scientifique

Universite Claude Bernard – Lyon1

Ecole Superieure De Physique Et De Chimie Industrielles De La Ville De Paris

Centre Leon Berard

Ecole SupÉrieure De Physique Et De Chimie Industrielles

De La Ville De Paris

Institut National De La Sante Et De La Recherche Medicale (inserm)—raison Sociale Obsolete

Centre Hospitalier National D'opthalmologie Quinze-vingts

Michael Atlan

Jean-Pierre Huignard

Stefan Catheline

Benjamin Samson

Léo Puyo

Gabrielle Laloy-Borgna

This computer-implemented method allows assessing the shear elasticity modulus of a flexible tube, such as a blood vessel. In the field of medicine, this allows assessing whether a blood vessel is at risk of breakage or tearing. In the case of an artificial tube to be implanted in a patient's body, this allows verifying that this tube is compatible with the patient's body. The method includes the following further steps: a) obtaining () a first dataset relating to spatiotemporal deformations of the tube; b) detecting and storing () a wall inner surface of the tube and its diameter (D); c) identifying () a number of transverse sections (Sij) of the tube; d) computing () an average particle velocity (Vij) over each section; e) computing () a wave propagation speed (C) of an antisymmetric wave (W); f) based on the wave propagation speed (C) and on the diameter (D), assessing () the shear elasticity modulus (μ) of the tube.

Computer-implemented method and apparatus for characterizing a flexible tube

According to a first aspect, the present disclosure relates to a digital holography device () for full-field blood flow imaging of ocular vessels of a field of view of a layer () of the eye (). The device comprises an optical source () configured for the generation of an illuminating beam (Eobj) and a reference beam (E), and a detector () configured to acquire a plurality of interferograms (I(x,y,t)) wherein an interferogram is defined as the signal resulting from the interference between the said reference beam (E) and a part of said illuminating beam (Eobj) that is backscattered from said layer (). The device further comprises a processing unit () configured for processing said plurality of interferograms, (I(x,y,t)), wherein said processing comprises: the calculation (), for each interferogram, of a hologram (H(x,y,t)), resulting in a first plurality of holograms; the selection (), in sequential time windows, (tw), of second pluralities of holograms; the calculation (), for each said second plurality of holograms, of a Doppler power spectrum (S(x,y,f)); the calculation (), based on said Doppler power spectrum, of at least a first Doppler image thus generating at least a first plurality of Doppler images; the processing of each first Doppler image, wherein said processing comprises the devignetting () of said first Doppler image, resulting in a devignetted first Doppler image; the normalization () of said devignetted first Doppler image based on a spatial average of an intensity of said first Doppler image, resulting in a normalized first Doppler image; and the subtraction (), from said normalized first Doppler image, of said spatial average of said intensity of said first Doppler image, resulting in a corrected first Doppler image.

Methods and devices for full-field ocular blood flow imaging

According to one aspect, the invention concerns an optical imaging device () for an object (OBJ) by off-axis holography comprising a light source () adapted for emitting an illumination wave (E) on the object, in transmission or reflection, and an assembly formed by one or more thick Bragg gratings () for receiving a wave (E) coming from the object thus illuminated and for deflecting a first component (E) of the wave coming from the object, called the reference wave, and to allow a second component (E) of the wave coming from the object, called the signal wave, to pass without deflection in such a way that the deflected reference wave presents predetermined deflection angles with respect to the non-deflected signal wave defined in two perpendicular planes. The imaging device according to the first aspect further comprises a two-dimensional detection device () for acquiring an interferogram resulting from the interference between said deflected reference wave and said signal wave and a computing unit for determining, from said interferogram, an amplitude and phase distribution of the signal wave in the plane of the object (hologram).

Devices and methods for optical imaging by means of off-axis digital holography

The invention relates to a digital holography method for detecting the vibration amplitude of an object () having a vibration frequency &#x3c9;, comprising: generating object illumination waves (W) and reference waves (W); acquiring interferograms between the reference wave (W) and a signal wave (W) by means of a bandwidth &#x3c9; s detector (), the reference wave comprising two components E, Eof frequencies &#x3c9;, &#x3c9;that are respectively staggered in relation to the laser frequency &#x3c9;by a quantity &#x3b4;=&#x3b3;&#x3c9;and &#x3b4;2=q&#x3c9;+&#x3b3;2&#x3c9;, where q is an integer and &#x2212;0.5&#x2266;&#x3b3;1, &#x3b3;&#x2266;0.5; and calculating the vibration amplitude of the object from the optical beats spectrum deduced from the complex amplitude of an interferogram.

Digital off-axis heterodyne holographic interferometry for detecting vibration amplitude

Growing community of inventors

Paris, France

Michael Atlan