Hardware implementation algorithm and error analysis of high-speed fluorescence lifetime sensing systems using center-of-mass method

Abstract

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Video-rate fluorescence lifetime imaging camera with CMOS single-photon avalanche diode arrays and high-speed imaging algorithm

“…We applied median filtering to remove the noisy pixels on FLIM images, and the noisy pixels were also excluded from the lifetime histogram solely to reveal the performance of the proposed algorithm. (14,12) marked as "O" and (6, 16) marked as "P" versus the frame number, respectively. During the video recording, the sample stage was initially static for 15 frames and it started to move.…”

“…The data was stored in memory and then post-processed using maximum-likelihoodestimation (MLE) or least-square method (LSM)-based curvefitting software pixel-by-pixel to generate a lifetime image. Although the MLE (or LSM) has merits of wide resolvability range and high photon efficiency, and usually hundreds of photons are enough to reach an acceptable accuracy, 14,15 the data acquisition is still slow (measurement time = N x × N y /f p , where f p is the scanning frequency and N x × N y is the dimension of the array) and limits the systems to imaging only stationary objects. In many biological applications, real-time FLIM imaging for monitoring cell dynamics in low light level is desirable.…”

“…14 It was proven to be suitable for sensing and confocal scanning applications. To apply the CMM for imaging applications, we need to collect arrival time information of every detected photon event for each pixel.…”

FPGA-based multi-channel fluorescence lifetime analysis of Fourier multiplexed frequency-sweeping lifetime imaging

“…Phasor analysis of frequency-domain or time-domain FLIM data can present a global and graphic view of FLIM data [10,11]. Center of mass method has been widely used in time-domain lifetime image analysis, and has been successfully implemented in FPGA for real-time calculation [9,12].…”

Upgrading time domain FLIM using an adaptive Monte Carlo data inflation algorithm

“…To address this issue, many recent efforts focused on reducing acquisition time by developing high-speed FLIM techniques, using specific detectors and dedicated electronic cards (18)(19)(20). In contrast, the work presented here uses a standard TCSPC FLIM acquisition system.…”