Computational qMAPP
Synthetic aperture or tomographic quantitative microscopy for amplitude, phase, and polarization
Conventional microscopy requires focusing the image by changing the distance between the objective and the sample. At ≥20× magnifications, changes of a few microns can bring an object in focus or make it completely dissappear, which makes surveying thicker samples, like cytopathology slides, very time-consuming.
Having to move heavy components for proper imaging severely limits the speed of conventional microscopy.
Our qMAPP measures the optical field transmitted/reflected by the sample to computationally generate the sample’s image at different focusing distances, fully digitally, post-detection.
Our system can reach orders of magnitude higher speeds and throughput through decoupling data acquisition from highly-parallelizable post-detection image reconstruction and analysis.
Principle of Operation
The sample is illuminated at different angles and the transmitted/reflected amplitude, phase, and polarization are measured. The image is reconstructed from the coherent superposition of the optical field measurements back-propagated to the desired distance.
Instead of relying on moving the microscope’s stage or its objective lens, the operator or the data processing algorithm simply selects a different reconstruction distance.
The reconstruction process is highly parallelizable and can be implemented on multiple GPUs/computers.
The system can be set up for both synthetic aperture and/or tomographic acquisition and reconstruction.
Inherent Phasing
Synthetic aperture and/or tomographic high-sensitivity phase and amplitude imaging requires coherently combining optical field measurements obtained at different illumination angles. Any uncontrolled phase changes between different data frames can significantly lower the quality of the image.
qMAPP measures the image-plane optical field using the SFS, which is inherently phase stable due to its common-path, phase-gradient detection.
qMAPP can be designed to trade one or more of data accuracy, sensitivity, and dynamic range for speed and/or system cost.
Super-resolved (synthetic aperture) image of a resolution target: 2% estimation error of absorption coefficient vs 26% in a conventional image (same camera, limited dynamic range).
Super-resolved (synthetic aperture) image of 0.5μm-diameter polystyrene beads in index matching fluid (very low contrast). Bar indicates resolution limit of the microscope objective used.
Label-Free Super-Resolution Microscopy
Most cells and tissues are naturally highly transparent. Conventional microscopy-based pathology requires staining and/or fluorescently labeling the samples. In addition to increasing cost, staining/labeling can introduce artifacts and/or interfere with live samples (e.g. cell cultures).
qMAPP interferometrically quantifies refractive index and optical density differences in the sample much more accurately than conventional microscopy.
Digital Focusing
Digital, post-detection, re-focusing is a data efficient, simple, linear operation. Unlike regular deconvolution techniques, it does not require acquiring images densely spaced around the Z positions where the target of interest is located.
Glass-like, through-volume, refocusing is possible post-detection, enabling data-efficient remoteDX and new types of feature-detection algorithms.
New insights can be gained on previously acquired, fully-digital microscope slide representations.
Post-detection digitally re-focused image of cells. Arrows: different features clearly distinguishable at different Z positions.
DIC vs Synthetic Aperture Microscopy
Focal plane arrays (and cameras) have limited dynamic range and sensitivity because of the low well depths of their pixels (especially at high resolutions). Low-contrast features, characteristic to unlabeled cells and tissue sections, are difficult to image. Below: 0.5μm-diameter polystyrene beads in index-matching fluid (very-low contrast).
DIC image at 40x/0.5: beads are unresolved and noisy
Super-resolved SA image from 40x/0.5 data.
Digital Post-Detection Focusing
For maximum throughput when imaging a thick sample, digital refocusing should function well outside the depth of field (DOF) of the imaging system. Conventional deconvolution breaks down at more than ∼2×DOF. Below we show the digitally refocused image of a resolution target at ∼17×DOF!
Log(Intensity) image of the defocused target (pseudo-color). Target too far, no features visible in conventional intensity (limited screen dynamic range).
Target is correctly reconstructed (pseudo-color), despite vignetting caused by the limited objective aperture (wavy features).
Let’s Work Together
Microscopy technology has not evolved in its general practice for a century: it is still a generally manual, difficult to scale, process.
Our technology is uniquely capable of fully-digital, high-accuracy, quantitative microscopy of stained and unstained samples.
Through synergistic collaboration, we can solve important health screening and diagnostic challenges, benefiting humanity.
Contact Us
We’re eager to learn about your requirements and happy to tell you more about our technology.
Ithaca, NY 14850
+1 917 436 1624
info@cdei.net