Endoscope Imaging System Variable Aperture Depth of Field
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Solution Overview
Problem
Conventional endoscopes struggle to provide a dynamic and expandable depth of field, limiting the amount of in-focus image information that can be utilized for accurate depth assessment in medical procedures.
Innovation Solution
A dynamic imaging system for endoscopes that utilizes a variable lens or actuated sensor to adjust the focal plane, combined with beam splitters and polarizing optics to separate and manipulate light beams, allowing for the capture and processing of multiple focal planes for enhanced depth of field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a static beam splitter arrangement is used to provide two separate imaging channels, then depth of field information can be reconstructed from two separately focused images, but the depth of field difference is static and limited to two focal planes
Solution Approach 1:
The patent applies the dynamics principle by introducing a variable lens that can dynamically adjust its focal length, transforming the static beam splitter arrangement into a dynamic system. This allows the endoscope to capture images at multiple different focal planes by changing the lens focal length, thereby expanding depth of field information beyond the limited two focal planes provided by static arrangements.
Solution Approach 2:
The patent employs parameter changes by varying the focal length of the lens as a key optical parameter. By adjusting this parameter, the system can capture images at different focal planes, enabling dynamic depth of field adjustment and providing adaptability to different imaging requirements while maintaining the benefit of separate imaging channels.
2Loss of information
If separate imaging channels with different path lengths are used, then depth information can be provided at two focal planes, but the amount of in-focus image information is limited
Solution Approach 1:
The patent applies the merging principle by combining multiple images captured at different focal planes into a single composite image with extended depth of field. This post-processing approach merges the information from separate imaging channels to maximize in-focus image content, effectively reducing information loss while utilizing the complexity of separate channels productively.
Solution Approach 2:
The patent employs preliminary action by capturing multiple images at different focal planes before processing. This preliminary capture of diverse focal information allows subsequent computational methods to select and combine the sharpest regions from each image, thereby maximizing the amount of in-focus information in the final composite image.
3Adaptability or versatility
If variable lens or actuated sensor is used to adjust focal plane, then usable depth of field is expanded, but system complexity increases
Solution Approach 1:
The patent applies mechanics substitution by replacing complex mechanical variable lens mechanisms with simpler fixed lens arrangements combined with digital image processing. Instead of mechanically adjusting the lens to change focal planes, the system captures multiple images with fixed optics and uses computational methods to achieve the equivalent effect, thereby reducing mechanical complexity while maintaining adaptability.
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
The system effectively expands the usable depth of field, enabling the capture of high-resolution images with improved depth information, while maintaining or even enhancing image resolution, thus overcoming the limitations of conventional endoscopes.
Implementation Method 1
The beam splitter 5 at the distal end of the endoscope 1 divides the incoming captured light into two channels
Implementation Method 2
The separate light beams may be differently polarized by a variable wave plate or a polarized beam splitter to allow separate manipulation of the beams
Implementation Method 3
The imaging system utilizes a variable lens to adjust the focal plane of the beam
Implementation Method 4
or an actuated sensor to adjust the detected focal plane
Data Source
AI summary
A dynamic imaging system for use with endoscope, or as an element of a video endoscope, utilizes path length differences and/or a variable aperture size to expand a usable depth of field and/or improve image resolution in an area of interest in the image field. In some implementations, the imaging system utilizes a variable aperture in conjunction with unequally spaced image sensors placed downstream from a beam splitter. An imaging system captures multiple focal planes of an image scene on separate sensors. A variable aperture permits the capture of enhanced resolution images or images with longer depths of field. These differently focused images and/or images with different resolutions and depths of field are then combined using image fusion techniques.