Fast Fluorescence Lifetime Imaging Method Based on Single Photon Avalanche Diode Detector

Abstract

The invention discloses a fast fluorescence lifetime imaging method based on a single-photon avalanche diode detector. The method uses a single-photon avalanche diode as a detection device, and performs photon sampling through discrete and aliasing multiplexed detection windows. Through the principle of Monte Carlo simulation, the fluorescence decay curve is fitted, and the fluorescence lifetime is calculated. The whole circuit work is divided into the preparation stage of detection, the detection stage and the readout stage. In the detection stage, the laser excites the fluorescence of the sample to be tested, and uses the control of the working state of the SPAD and the gating signal to control the gating of the avalanche pulse caused by the photon to realize the window detection of discrete and aliasing, and record the detected data down. The invention utilizes the discrete and aliasing multiplexing detection method to expand the optimal detection range of the time detection window method and reduce detection errors. Two counting modules are integrated in each pixel unit, so that two sets of data can be sampled after a single fluorescence excitation, which can effectively improve the imaging speed.

Description

technical field [0001] The invention belongs to the field of optoelectronic technology, and in particular relates to a fast fluorescence lifetime imaging method based on single-photon detection technology. Background technique [0002] Due to its high sensitivity and molecular specificity, as well as its non-destructive measurement method, fluorescence lifetime imaging can measure many biophysical parameters in the microenvironment of the test sample, such as oxygen pressure, solution, hydrophobicity, etc. and biochemical parameters. Quantitative measurement such as pH value ion concentration has important applications. In the process of fluorescence lifetime imaging, fluorescence photons need to be detected. Single-photon avalanche diode (SPAD) detectors have high sensitivity and high time-precision resolution, and have been widely used in biomedicine, military, and optical communications. They are very suitable as photon detectors in fluorescence lifetime imaging systems....

AI Technical Summary

Problems solved by technology

Moreover, the detection window of the traditional fluorescence lifetime measurement method is mostly continuous or aliased detection, and the sampling range is mostly concentrated in the front part of the fluorescence decay, and the data obtained by sampling are not representative, which will cause certain calculation errors and can ensure a small The optimal detection range of errors is small, which is not conducive to general application

In addition, since only one counting circuit is included in the pixel circuit, only one set of data can be detected in each laser excitation cycle, which will lead to a slow imaging speed.

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