Aperture Diaphragm for Fluorescence Imaging Light Balance
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Solution Overview
Problem
Current light source devices struggle to balance the intensity of illumination light and excitation light in the visible and infrared regions, leading to fluorescence images being buried within subject images in medical imaging applications, particularly in photodynamic diagnosis and therapy, due to the complexity of existing solutions such as RGB separation and optical filter configurations.
Innovation Solution
A light source device employing an aperture diaphragm that transmits excitation light wavelengths without attenuation while reducing visible light transmission, allowing for a variable aperture region to balance the light quantities between fluorescence and subject images, thereby preventing fluorescence images from being obscured by subject images in a simplified system configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a white light source is used to provide both illumination light and excitation light, then the system configuration is simplified, but the fluorescence image becomes buried in the subject image due to excessive visible light intensity
Solution Approach 1:
The aperture diaphragm is divided into a filter region with light-blocking properties and an aperture region with light-transmitting properties. The filter region blocks visible light to prevent it from burying the fluorescence image, while the aperture region transmits excitation light to enable fluorescence excitation. This segmentation allows simultaneous simplification of the light source system and preservation of fluorescence image visibility.
Solution Approach 2:
Different regions of the aperture diaphragm are assigned different optical properties: the filter region has light-blocking properties for visible wavelengths, while the aperture region has light-transmitting properties for excitation wavelengths. This local differentiation of optical characteristics enables the system to simultaneously achieve simple configuration and effective fluorescence imaging.
2Measurement precision
If an aperture diaphragm with a filter region is used to block visible light, then fluorescence image visibility is improved, but excitation light transmission may be attenuated
Solution Approach 1:
The aperture diaphragm is segmented into a filter region that blocks visible light and an aperture region that transmits excitation light. This segmentation ensures that the filter region does not interfere with excitation light transmission, as the aperture region remains fully transparent for the excitation wavelength band, thereby preventing energy loss while improving fluorescence visibility.
Solution Approach 2:
The aperture diaphragm acts as an intermediary optical element that selectively manages light transmission. By positioning it in the optical path between the light source and the subject, it can block visible light without affecting excitation light, as the aperture region maintains full transparency for excitation wavelengths.
3Measurement precision
If RGB separation and recombination is used to emphasize fluorescent light, then fluorescence visibility is improved, but the system complexity increases due to required filters and driving mechanisms
Solution Approach 1:
Instead of using complex RGB separation and recombination mechanisms, the invention extracts and blocks only the harmful visible light component using a filter region in the aperture diaphragm. This extraction approach eliminates the need for multiple filters and driving mechanisms while achieving the same goal of enhancing fluorescence visibility.
Solution Approach 2:
The invention replaces the complex RGB separation system with a simpler aperture diaphragm structure that achieves the same effect of emphasizing fluorescence. The aperture diaphragm with its filter and aperture regions serves as a simplified copy or alternative implementation that achieves fluorescence enhancement without requiring RGB separation machinery.
4Measurement precision
If optical filters with different transmittances are used to balance infrared and visible light, then fluorescence and subject image balance is improved, but the filter design becomes extremely difficult when fluorescence light is very weak
Solution Approach 1:
The aperture diaphragm is segmented into a filter region and an aperture region. The filter region is designed to block visible light while the aperture region transmits excitation light. This segmentation simplifies the design process by separating the light control functions into distinct regions, making it easier to manufacture compared to designing a single complex filter with multiple transmittance characteristics.
Solution Approach 2:
Different regions of the aperture diaphragm have different optical properties: the filter region has light-blocking properties and the aperture region has light-transmitting properties. This local quality differentiation simplifies manufacturing by allowing each region to be designed and fabricated independently with its specific optical characteristics, rather than requiring a single complex filter structure.
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
This solution effectively enhances the visibility of fluorescence images by adjusting the light ratio between fluorescence and subject images, improving the clarity of observations without increasing system complexity, using a white light source and a doughnut-shaped or rotary aperture diaphragm to control light transmission.
Implementation Method 1
an aperture diaphragm having a filter region that reduces or blocks light in a visible light region for forming a subject image and an aperture region that transmits light in a wavelength region of excitation light
Implementation Method 2
the property of a light-sensitive substance that is distinctively accumulated in tumor bearing tissue and emits fluorescent light when being irradiated with excitation light
Data Source
Figure 1(a)~1(b)
Figure 2(a)~2(b)
Figure 3(a)~3(b)
AI summary
An illumination aperture diaphragm 100A which is used in a light source device to simultaneously observe a subject image formed by reflected illumination light in the visible light region and a fluorescence image from a fluorescent substance in a subject has a filter region 1 formed in a flat plate-like base material 3 and an aperture region 2 formed inside the filter region 1. The filter region 1 transmits light in the wavelength region of excitation light for allowing the subject to emit fluorescent light and reduces or blocks the transmission of the light in the visible light region that forms the subject image. An illumination aperture diaphragm 200A may include a plurality of diaphragm blade members 20A which are each provided partially or entirely with a filter portion 21, so that a filter region 1 is formed of the plurality of diaphragm blade members 20A and an aperture region 2 is formed inside the filter region 1. This can provide an improved ratio in the quantity of light between the subject image provided by the reflected illumination light and the weak fluorescence image provided by the fluorescent substance in the subject.