Synthetic exposure with a CMOS camera for multiple exposure speckle imaging of blood flow - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Scientific Reports Année : 2022

Synthetic exposure with a CMOS camera for multiple exposure speckle imaging of blood flow

Résumé

Abstract Speckle contrast imaging is an established technique to obtain relative blood flow maps over wide fields of view. A major improvement of the method relies on the acquisition of raw speckle images at different exposure times but requires simultaneous modulation of a laser pulse in duration and intensity and precise synchronization with a camera. This complex instrumentation has limited the use of multiple exposure speckle imaging. We evaluate here the use of a CMOS camera for a simplified approach based on synthetic exposure images created from the sum of successive frames acquired at a 1 ms exposure time. Both methods have been applied to evaluate controlled flows in micro-channels. The contribution of noises to the speckle contrast have been quantified and compared. Dark, readout and shot noise contributions to the total contrast remain constant for modulated exposure, while all these contributions decrease with increasing exposure time for synthetic exposure. The relative contribution of noises to speckle contrast depends on the level of illumination and the exposure time. Guidelines for flow measurements and limitations of the use of a CMOS camera with a limited frame rate for synthetic exposure acquisition scheme are discussed. The synthetic exposure method is simple to implement and should facilitate the translation of multiple exposure speckle imaging to clinical set-ups.
Fichier principal
Vignette du fichier
Chammas _sci reports_2022.pdf (1.64 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-03613562 , version 1 (18-03-2022)

Identifiants

Citer

Marc Chammas, Frederic Pain. Synthetic exposure with a CMOS camera for multiple exposure speckle imaging of blood flow. Scientific Reports, 2022, 12 (1), pp.4708. ⟨10.1038/s41598-022-08647-6⟩. ⟨hal-03613562⟩

Relations

36 Consultations
27 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More