Field programmable gate array compression for large array multispeckle diffuse correlation spectroscopy
Open Access
- 1 May 2023
- journal article
- research article
- Published by SPIE-Intl Soc Optical Eng in Journal of Biomedical Optics
- Vol. 28 (05), 057001
- https://doi.org/10.1117/1.jbo.28.5.057001
Abstract
SignificanceDiffuse correlation spectroscopy (DCS) is an indispensable tool for quantifying cerebral blood flow noninvasively by measuring the autocorrelation function (ACF) of the diffused light. Recently, a multispeckle DCS approach was proposed to scale up the sensitivity with the number of independent speckle measurements, leveraging the rapid development of single-photon avalanche diode (SPAD) cameras. However, the extremely high data rate from advanced SPAD cameras is beyond the data transfer rate commonly available and requires specialized high-performance computation to calculate large number of autocorrelators (ACs) for real-time measurements.AimWe aim to demonstrate a data compression scheme in the readout field-programmable gate array (FPGA) of a large-pixel-count SPAD camera. On-FPGA, data compression should democratize SPAD cameras and streamline system integration for multispeckle DCS.ApproachWe present a 192 × 128 SPAD array with 128 linear ACs embedded on an FPGA to calculate 12,288 ACFs in real time.ResultsWe achieved a signal-to-noise ratio (SNR) gain of 110 over a single-pixel DCS system and more than threefold increase in SNR with respect to the state-of-the-art multispeckle DCS.ConclusionsThe FPGA-embedded autocorrelation algorithm offers a scalable data compression method to large SPAD array, which can improve the sensitivity and usability of multispeckle DCS instruments.Keywords
This publication has 17 references indexed in Scilit:
- A multipixel diffuse correlation spectroscopy system based on a single photon avalanche diode arrayJournal of Biophotonics, 2019
- A $192\times128$ Time Correlated SPAD Image Sensor in 40-nm CMOS TechnologyIEEE Journal of Solid-State Circuits, 2019
- Establishing the diffuse correlation spectroscopy signal relationship with blood flowNeurophotonics, 2016
- Diffuse correlation spectroscopy for measurement of cerebral blood flow: future prospectsNeurophotonics, 2014
- Diffuse correlation spectroscopy for non-invasive, micro-vascular cerebral blood flow measurementNeuroImage, 2013
- FPGA implementation of a 32x32 autocorrelator array for analysis of fast image series.Optics Express, 2012
- Detrimental effects of speckle-pixel size matching in laser speckle contrast imagingOptics Letters, 2008
- Fiber-based multispeckle detection for time-resolved diffusing-wave spectroscopy: characterization and application to blood flow detection in deep tissueApplied Optics, 2007
- Diffuse optical correlation tomography of cerebral blood flow during cortical spreading depression in rat brainOptics Express, 2006
- Diffuse optical measurement of blood flow, blood oxygenation, and metabolism in a human brain during sensorimotor cortex activationOptics Letters, 2004