High Dynamic Range Imaging Using Diminishing Laser Pulses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current imaging techniques in fluorescence microscopy are limited by a low dynamic range, which is insufficient for capturing both bright and faint structures in a sample, particularly in applications like neural activity imaging, due to detector saturation and integration time limitations.
Innovation Solution
An imaging system that generates successive light pulses of diminishing intensity and processes signals based on these intensities, using a delay loop and beam splitters to create a series of pulses with controlled intervals, allowing for high dynamic range imaging by selecting appropriate buffer data for each focal point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the gain or integration time of the detector is increased to detect faint structures, then the detection sensitivity is improved, but the brightest objects in the sample saturate the detection system
Solution Approach 1:
The patent segments the detection process by dividing the field of view into multiple regions with different exposure parameters. Bright structures are captured with shorter integration times or lower gain settings, while faint structures are captured with longer integration times or higher gain settings. This segmentation allows each region to be optimized independently, preventing saturation of bright areas while enhancing detection of faint areas.
Solution Approach 2:
The patent employs dynamic adjustment of detector gain and integration time based on the local intensity characteristics of different regions in the sample. The system dynamically selects appropriate detection parameters for each region, transitioning between different detection modes to accommodate the wide range of intensities present in the field of view.
2Productivity
If a single integration time is used for the detector, then the detection speed is maintained, but both bright and faint structures cannot be simultaneously captured with adequate detail
Solution Approach 1:
The patent implements periodic capture of the same field of view at different integration times or gain settings. Multiple images are acquired in sequence with varying detection parameters, and then computationally combined to produce a final image that preserves both bright and faint structures. This periodic multi-parameter sampling enables comprehensive dynamic range coverage while maintaining reasonable detection speed through efficient image processing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the creation of high dynamic range images by overcoming detector saturation and integration time limitations, effectively capturing both bright and faint structures in a sample.
Implementation Method 1
a pulse laser configured to generate light pulses having a repetition interval
Implementation Method 2
a first beam splitter configured to receive a light pulse and to direct a first percentage of the light pulse onto a delay loop and output a second percentage of the light pulse
Implementation Method 3
the delay loop is configured to direct the first percentage of light pulse back to the first beam splitter with a time delay
Implementation Method 4
a photodetector configured to collect photons generated within the target volume in response to excitation of the target volume by the first and second sub-pulses
Implementation Method 5
the sample objective is configured to focus the successive light pulses at a focal plane within a sample
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system for generating a series of reducing intensity laser pulses from an ultrafast pulsed laser source. The reducing intensity series of pulses is equally temporally spaced between pulses from the laser source. The repeating series of reducing intensity laser pulses is fed to a microscope for imaging. The microscope is capable of detecting the fluorescence from a sample generated by each pulse in the series. The data is processed using knowledge of the pulse intensity, location on the test sample, and amount of fluorescence measured to create an increased dynamic range of the image relative to what can be obtained in a normal two-photon imaging system.