Angled OCT Probe Cannula Lens Back Reflection
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Solution Overview
Problem
Conventional OCT probes face challenges in minimizing back reflection due to the difficulty and expense of fabricating a lens with a small, angled surface, which is critical for reducing undesirable light signals and improving optical performance.
Innovation Solution
The OCT probe design features a cannula with an angled distal segment and a lens with parallel proximal and distal sides, allowing light reflected from the lens to be misaligned with the optical fiber path, reducing back reflection and simplifying manufacturing by eliminating the need for an angled lens surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the lens first surface is fabricated with an angled surface to reflect light away from the return path, then back reflection is reduced and optical performance is improved, but manufacturing difficulty and cost increase due to small dimensional scale and tight tolerances
Solution Approach 1:
The optical system is segmented into two functional components: a standard lens with a planar first surface and an angled window or housing structure. The lens maintains its simple planar geometry for easy manufacturing, while the angled structure performs the light redirection function, separating the focusing and angle-control functions into distinct elements.
Solution Approach 2:
An intermediary angled window or housing structure is introduced between the lens and the optical fiber. This intermediary element performs the light angle modification function, allowing the lens itself to remain simple and easy to manufacture while still achieving the desired back reflection reduction through the combined optical path.
2Object-generated harmful factors
If the lens first surface is fabricated with an angled surface to minimize back reflection, then light signal quality is improved, but manufacturing cost increases due to complex fabrication requirements
Solution Approach 1:
The angled surface function is extracted from the lens itself and placed into a separate window or housing structure. This allows the lens to be manufactured as a simple, low-cost planar element while the angled structure, which can be made from standard optical materials, performs the back reflection reduction function.
Solution Approach 2:
The angled window or housing structure can be manufactured using simpler, more cost-effective methods compared to precision angular lens fabrication. This substitute structure achieves the same optical function at lower manufacturing cost, making the overall system more economical despite the specialized geometry.
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 design enhances the optical signal-to-noise ratio by minimizing back-reflected light, making the OCT probe easier and less expensive to manufacture while maintaining effective imaging capabilities.
Implementation Method 1
the proximal side being disposed relative to the fiber so that light emitted through the fiber and reflected from the proximal side reflects at an angle misaligned with the fiber
Data Source
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AI summary
An OCT probe for imaging patient tissue includes a probe housing, and includes a cannula extending from the probe housing and arranged to penetrate patient tissue. The cannula may include a main body segment and a distal segment. The main body segment may have a lumen defining a first central axis, and the distal segment may have a lumen defining a second central axis that is angled from the first central axis. A lens is disposed in the distal segment. The lens may have a proximal side and a distal side and an optical axis. The optical axis may be substantially parallel to the second central axis and may be angled relative to the first central axis.