Differential Phase Contrast Microscope With Conjugate Pupil Filtering
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Solution Overview
Problem
Conventional differential phase contrast microscopy is limited by high costs and restricted user access due to the need for dedicated objectives and motorized stages, and is inefficient in multi-well plates due to reduced illumination angles and pupil plane filter adaptation requirements for various magnifications and numerical apertures.
Innovation Solution
A microscope design incorporating an infinity-corrected objective, tube lens, and adjustable aperture stop at a conjugate back focal plane, with a configurable illumination source that can illuminate the object from multiple angularly displaced positions, allowing for adaptable pupil plane filtering and standard objective use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional phase contrast microscopy uses dedicated objectives with embedded phase plates, then phase contrast imaging is achieved, but cost increases and user access is restricted
Solution Approach 1:
The invention extracts the phase plate from the objective and relocates it to the condenser turret, allowing standard objectives to be used while maintaining phase contrast capability. This separation reduces the need for specialized expensive objectives.
Solution Approach 2:
The condenser turret is designed to accommodate multiple phase plates with different phase shifts, enabling a single microscope system to perform phase contrast imaging across multiple objectives and magnifications, increasing universality and reducing overall system cost.
2Device complexity
If conventional DPC uses a standard objective for pupil plane filtering, then cost is reduced, but efficiency of phase-to-amplitude conversion is significantly reduced in multi-well plates
Solution Approach 1:
The invention introduces an annular aperture that matches the specific illumination geometry of multi-well plates, optimizing the pupil plane filter for the local conditions of reduced illumination angles. This restores phase-to-amplitude conversion efficiency specifically for multi-well plate applications.
Solution Approach 2:
The aperture shape is changed from circular to annular, and the aperture parameters are optimized for the reduced numerical aperture and specific illumination angles encountered in multi-well plate microscopy, thereby improving conversion efficiency for this specific application.
3Device complexity
If conventional DPC uses a fixed pupil plane filter, then system is simple, but adaptability to different magnifications and numerical apertures is limited
Solution Approach 1:
The invention implements a motorized turret that can rotate to position different phase plates and aperture combinations according to the selected objective magnification and numerical aperture. This dynamic adaptation allows the system to optimize performance for each objective while maintaining overall system simplicity.
Solution Approach 2:
The system pre-configures multiple phase plates and aperture settings corresponding to different objective specifications. When an objective is selected, the appropriate pre-configured settings are automatically engaged, eliminating the need for real-time calculations or manual adjustments.
4Ease of operation
If conventional DPC requires motorized stage for phase-plate conjugate plane switching, then illumination matching is achieved, but device complexity and cost increase
Solution Approach 1:
The invention replaces the motorized stage mechanism with a motorized turret that rotates to bring different phase plates into the correct conjugate plane. This substitution achieves the same illumination matching function while using a more compact and cost-effective mechanical system.
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
Enables efficient phase-to-amplitude conversion and enhanced contrast imaging across a range of magnifications and numerical apertures, including in multi-well plates, while reducing costs and improving user accessibility.
Implementation Method 1
Local phase gradients within the specimen cause incident light to be diffracted in proportion to the steepness of the local gradient. Phase-to-amplitude conversion is performed whereby incident light encountering local phase gradients is diffracted such that it is blocked at a pupil plane aperture
Data Source
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Figure 3A~3C
AI summary
A microscope for performing differential phase contrast (DPC) microscopy comprises an infinity-corrected microscope objective and a tube lens, and at least one lens configured to image a back focal plane of the microscope objective to a conjugate back focal plane outside of the microscope objective. An aperture stop is located at said conjugate back focal plane. The object plane is located between the objective and the illumination source, the illumination source being configurable to illuminate the object from any one of a plurality of locations that are angularly displaced about an axis that is perpendicular to the object plane. The illumination source is placed at a working distance from the object to allow the user unrestricted access to the specimen area. The microscope may use a standard objective, which reduces cost.