Vision Catheter Window Geometry for Wider Internal Field of View
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Solution Overview
Problem
Existing catheters with vision devices have a large portion of the field of view obstructed by the catheter, limiting the operator's ability to verify correct positioning within the body.
Innovation Solution
A catheter design with a vision lumen and window surfaces angled non-orthogonal to the optical axis, allowing the view direction to be refracted away from the catheter, using a window material with a higher refractive index than air, and optionally omitting a lens arrangement to enhance the field of view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a standard orthogonal window is used in the catheter, then the manufacturing process is simple and cost-effective, but the field of view is obstructed by the catheter tube
Solution Approach 1:
The window is designed with asymmetric orientation where the interior window surface is angled at a first angle relative to the optical axis, and the exterior window surface is angled at a second angle relative to the optical axis. These angles are specifically configured to refract light rays and redirect the effective view direction away from the catheter tube, thereby expanding the visible field of view while maintaining manufacturing feasibility through angled cutting or molding processes.
2Area of stationary object
If the window surfaces are angled non-orthogonal to the optical axis, then the field of view is improved by refracting light away from the catheter, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies particular angle ranges for the interior and exterior window surfaces relative to the optical axis. By defining these angular parameters within specific ranges, the design optimizes the refraction of light rays to redirect the effective view direction away from the catheter tube while maintaining manufacturability. The angled surfaces are configured to achieve the desired field of view expansion without requiring excessively precise manufacturing tolerances.
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 design provides an improved field of view by reducing the catheter's obstruction, enabling better anatomical visualization while maintaining navigability and allowing for a cost-effective manufacturing process.
Implementation Method 1
the interior window surface and/or the exterior window surface is/are non-orthogonal with respect to the optical axis of the vision module... a view direction of the vision module may thus, upon passing the window, effectively refracted away from the catheter
Implementation Method 2
The window may comprise a window material, such as polycarbonate, having a refraction index different from air... a refractive index of window material, e.g. polycarbonate, may be higher than a refractive index of an internal medium, e.g. air
Data Source
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AI summary
A catheter having a distal end for insertion into a patient, and comprising: a catheter tube enclosing at least a first catheter lumen and a vision lumen separated from the first catheter lumen, the first catheter lumen having a first distal opening at the distal end of the catheter; a window closing off a distal end of the vision lumen and having a planar interior window surface facing the vision lumen and a planar exterior window surface; and a vision device positioned in the vision lumen and comprising a vision module, such as a camera with an image sensor or an optical fibre, having an optical axis extending through the window; wherein the interior window surface and/or the exterior window surface is/are non-orthogonal with respect to the optical axis of the vision module, and the window surfaces are non-parallel.