Impact of logarithmic and linear spaced camera exposure durations for multi-exposure speckle imaging

Adam Santorelli; Christopher Smith; Andrew K. Dunn

doi:10.1117/12.2648443

7 March 2023 Impact of logarithmic and linear spaced camera exposure durations for multi-exposure speckle imaging

Adam Santorelli, Christopher Smith, Andrew K. Dunn

Proceedings Volume 12378, Dynamics and Fluctuations in Biomedical Photonics XX; 1237803 (2023) https://doi.org/10.1117/12.2648443
Event: SPIE BiOS, 2023, San Francisco, California, United States

Abstract

Neurosurgical interventions benefit greatly from monitoring of cerebral blood flow (CBF). Laser speckle contrast imaging (LSCI) is a label-free optical imaging technique that can provide continuous, high spatiotemporal maps of flow dynamics, allowing clinicians to monitor changes in CBF without any interruption to the surgical workflow. Multi-exposure speckle imaging (MESI) is an extension of LSCI that collects speckle images at numerous camera exposure times to create reproducible and quantifiable measurements of flow, through a more robust calculation of the correlation time constant. This work is focused on investigating whether the chosen spacing of the camera exposure times can impact the resulting computation of the inverse correlation time (ICT). A microfluidic phantom using a pressure-regulated flow control system is used to generate a 5-step and 7-step flow profile. MESI data is collected with three different exposure time spacings; logarithmic-spaced, linear-spaced, and the ad hoc exposure times from previous research. Using a nonlinear least squares fitting algorithm we fit the measured data to solve for the speckle correlation time constant at each MESI frame. We compare the quantified flow, based on the computed ICT for each exposure time collection method. These results suggest that future research and clinical adaptations should consider implementing logarithmic -spaced exposure times for MESI as it may provide more reliable and accurate estimates of flow, as well as faster acquisition times, without the need for specially chosen exposure times.

Conference Presentation

Citation Download Citation

Adam Santorelli, Christopher Smith, and Andrew K. Dunn "Impact of logarithmic and linear spaced camera exposure durations for multi-exposure speckle imaging", Proc. SPIE 12378, Dynamics and Fluctuations in Biomedical Photonics XX, 1237803 (7 March 2023); https://doi.org/10.1117/12.2648443

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available