Methods and devices for full-field ocular blood flow imaging

Abstract

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.