Rotating Dichroic Filter Light Source for Endoscope Fluorescence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional endoscope apparatuses face limitations in effectively switching between normal observation and fluorescence observation modes, particularly in ensuring sufficient excitation light for fluorescence detection, which can lead to inadequate detection of abnormal tissues like cancerous cells.
Innovation Solution
A light source device with a rotating plate that includes a first window for transmitting illumination light in a first wavelength band and a second window for transmitting illumination light in a second wavelength band, along with a second light source and optical device to enhance excitation light during fluorescence observation, allowing for improved light condensation and reflection to increase the amount of excitation light applied to the tissue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a rotating filter with excitation light filter is used for fluorescence observation, then fluorescence detection is enabled, but the amount of excitation light is insufficient
Solution Approach 1:
The patent combines a first light source (halogen lamp) for normal observation and a second light source (blue LED) for fluorescence observation into a single light source device. The optical device merges the optical paths of both light sources, allowing excitation light from the blue LED to be reflected onto the rotating filter and then to the subject, thereby increasing the amount of excitation light available for fluorescence detection
Solution Approach 2:
The optical device serves multiple functions: it transmits illumination light from the halogen lamp during normal observation mode and reflects excitation light from the blue LED during fluorescence observation mode. This multi-functionality allows a single device to support both observation modes effectively
2Illumination intensity
If a blue LED is placed at the distal end for fluorescence observation, then excitation light amount is increased, but heat-related power considerations arise
Solution Approach 1:
Instead of placing the blue LED at the distal end (inside the endoscope insertion portion), the patent inverts the arrangement by placing the blue LED at the proximal end (in the light source device). The excitation light is then transmitted through an optical fiber or optical path to reach the subject, reducing heat generation at the distal end while still providing sufficient excitation light
3Adaptability or versatility
If switching between normal and fluorescence modes is implemented, then observation versatility is improved, but device complexity increases
Solution Approach 1:
The patent employs a rotating filter mechanism that dynamically switches between different filter positions to enable mode switching. The rotating filter with excitation light filter and other filters allows the system to transition between normal observation and fluorescence observation modes by rotating to the appropriate filter position, providing adaptability without requiring completely separate optical paths for each mode
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 configuration enables effective switching between normal and fluorescence observation modes, providing a higher amount of excitation light for improved fluorescence detection, allowing for better differentiation between normal and abnormal tissues, such as cancerous cells, and reducing the need for a blue LED at the distal end, thus minimizing heat-related power considerations.
Implementation Method 1
an optical device which is arranged at the rotating plate, can transmit the illumination light emitted from the first light source, and can reflect the illumination light emitted from the second light source to the light condensing portion
Implementation Method 2
a light condensing portion which is arranged on an optical axis of illumination light emitted from the first light source and condenses light
Implementation Method 3
a rotating plate which has a first window portion that transmits illumination light in the first wavelength band and a second window portion that transmits at least illumination light in the second wavelength band
Data Source
AI summary
A switching filter is provided in a light source device. The switching filter has a first dichroic filter which transmits illumination light in a first wavelength band from a lamp and a fluorescence observation filter which transmits at least illumination light in a second wavelength band and is rotatably provided such that the first dichroic filter and the fluorescence observation filter pass through an illumination light optical axis. An LED portion has a blue LED which emits illumination light in the first wavelength band toward the switching filter. A second dichroic filter capable of transmitting illumination light from the lamp and reflecting illumination light from the LED portion to a condenser lens is also arranged at the switching filter.