Exoscope Dual Optical Path Depth of Field Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Surgical microscopes face a trade-off between high magnification and optical resolution, which results in a small depth of field, making it difficult for surgeons to maintain anatomical landmarks in focus during procedures, particularly in minimally invasive surgeries like brain surgery, where anatomical context is crucial.
Innovation Solution
An exoscope with two optical paths is implemented, one with a fixed path length and image plane for stable focus and another with a variable path length and image plane, using a varifocal lens or moveable lenses, combined using a beamsplitter to enhance depth of field imaging, allowing for improved visualization and context during surgical procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high magnification and optical resolution are used, then visualization power is improved, but depth of field becomes smaller
Solution Approach 1:
The system divides the imaging function into two separate optical paths: a first optical path with fixed focus for high-resolution imaging of the surgical site, and a second optical path with variable focus for capturing anatomical landmarks at different depths. This segmentation allows each path to be optimized for its specific function, resolving the contradiction between high magnification and adequate depth of field.
Solution Approach 2:
The system extends the depth of field by adding a temporal dimension through image fusion. The variable focus optical path captures images at different focal planes, which are then computationally combined to create an extended depth of field image, effectively adding a time-based dimension to overcome the spatial limitation of shallow depth of field.
2Stability of the object's composition
If fixed focus is used, then image stability is improved, but ability to capture multiple depth planes is reduced
Solution Approach 1:
The system merges the outputs of two optical paths with different focusing characteristics. The first optical path provides stable, fixed-focus imaging of the surgical site, while the second optical path provides variable-focus imaging of anatomical landmarks. The combined image fusion process integrates both streams, preserving the stability of the primary view while adding the adaptability to capture multiple depth planes through the variable focus path.
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 enables surgeons to maintain better depth cues and context, reducing trauma to brain tissue and minimizing the accidental resection of healthy tissue by providing an extended depth of field, thus enhancing the precision and safety of minimally invasive surgical procedures.
Implementation Method 1
a beamsplitter positioned in both the first optical path and the second optical path, the beamsplitter configured to: combine the first optical path and the second optical path between the beamsplitter and both the fixed image plane and the variable image plane; and direct respective light from each of the first optical path and the second optical path respectively towards the first image detector and the second image detector
Implementation Method 2
The variable optical path length may be achieved using a varifocal lens, such as a liquid-based varifocal lens and/or a moveable plenoptic array of lenses and/or an optic wheel and/or a moveable lens
Data Source
AI summary
An exoscope with enhanced depth of field imaging is provided. The exoscope includes first and second sets of optical devices, the first set having a fixed image plane, the second set having a variable image plane adjacent the fixed image plane of the first set. The second set includes at least one variable device configured to change the position of the variable image plane. A beamsplitter splits light from a combined optical path of the first and second set to respective image devices of the first and second set of optical devices. A controller controls the at least one variable device to change the position of the variable image plane relative to the fixed image plane, combines images acquired by the respective image devices, and controls a display device to render a combined image.