Non-Contact Raman Probe Optics for Precise Tissue Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing Raman spectroscopy probes face challenges in maintaining collection efficiency and spatial specificity when operating in non-contact mode, particularly in small body cavities, due to diverging light and reduced ability to couple backscattered light into fibers.
Innovation Solution
A non-contact Raman spectroscopy probe design featuring a crystalline lens and optical filters that focus excitation light and collect Raman scattering light without contact, combined with a guidance mechanism for precise positioning, allowing dual-region spectral acquisition and spatially isolated signal detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If fiber optic probe is removed from contacting the sample for non-contact acquisition, then ease of operation is improved, but collection efficiency of Raman scattered light deteriorates
Solution Approach 1:
A lens is introduced as an intermediary optical element between the diverging laser beam and the target tissue, and between the tissue and the collection fiber. The lens focuses the excitation light onto a smaller spot on the tissue while simultaneously collecting and directing the Raman scattered light into the fiber, thereby maintaining high collection efficiency in non-contact mode
Solution Approach 2:
The system transitions from direct axial contact coupling to a configuration involving focal plane geometry. By positioning the lens to create a focused spot at a specific distance from the fiber tip, the system utilizes the focal dimension to achieve both non-contact operation and efficient light coupling
2Ease of operation
If fiber optic is removed from contacting the sample, then ease of operation is improved, but spatial specificity of Raman signal deteriorates
Solution Approach 1:
The lens serves as a spatial filtering intermediary that concentrates the excitation light into a tight focal spot on the tissue surface. This focused illumination geometry ensures that only a localized region of the tissue is excited, thereby maintaining spatial specificity even when the probe does not physically contact the sample
Solution Approach 2:
The lens creates a localized focused spot of excitation light at a specific position on the tissue, concentrating the optical energy into a small volume. This local quality of focused illumination ensures that the Raman signal originates from a specific spatial region, preserving spatial specificity in non-contact mode
3Ease of operation
If laser light is allowed to diverge during non-contact acquisition, then ease of operation is improved, but collection efficiency of Raman signal deteriorates
Solution Approach 1:
The lens acts as an optical intermediary that counteracts the natural divergence of the laser beam. By positioning the lens at an appropriate distance from the fiber tip, it reconverges the diverging light into a focused spot on the tissue, thereby maintaining high collection efficiency without requiring physical contact
4Ease of operation
If excitation light covers larger area of tissue during non-contact acquisition, then ease of operation is improved, but spatial specificity of Raman signal deteriorates
Solution Approach 1:
The lens transforms the two-dimensional diverging beam into a concentrated three-dimensional focal spot. By utilizing the focal plane geometry, the system achieves tight spatial confinement of the excitation light to a small volume on the tissue, thereby maintaining spatial specificity in non-contact 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
The probe maintains collection efficiency and spatial specificity, enabling reliable and repeatable Raman spectrum acquisition in non-contact mode, particularly in small body cavities, by using a crystalline lens to focus excitation and minimize lens interference, and incorporating optical filters and guidance mechanisms for precise positioning.
Implementation Method 1
a lens positioned between the working ends of the at least one first fiber and the at least one second fiber and the target site for focusing the excitation light onto the target site and retrieving collection efficiency of the Raman scattering light
Implementation Method 2
incorporating optical filters and guidance mechanisms for precise positioning
Implementation Method 3
RS utilizes the inelastic scattering interaction to analyze the presence and abundance of biomolecules relating to sample composition
Data Source
AI summary
A non-contact clinical Raman spectroscopy guided probe includes at least one first fiber operably coupled with a first light source and having a working end for delivering excitation light emitted from the first light source to the target site; at least one second fiber operably coupled with a detector and having a working end for collecting Raman scattering light scattered from the target site in response to excitation by the excitation light to the detector; and a lens positioned between the working ends of the at least one first fiber and the at least one second fiber and the target site for focusing the excitation light onto the target site and retrieving collection efficiency of the Raman scattering light. The probe is also guided during device positioning to provide the user with feedback on orientation in the lateral and axial directions to repeatably measure specific locations on the target site.