MCAM refers to an assembly of microscopes, usually in a rectangular array-like fashion where each microscope module consists of a lens and a sensor. Here we first discuss basic assumptions and design parameters that are involved in designing such systems. We then broadly classify these systems into three configuration categories, where each of them primarily differ in resolution and field of view as discussed below.
Main assumptions for the imaging systems:
- Imaging through a planar array which consists of identical imaging system arranged in uniform grid.
- The imaging sample is a large 2D sample.
Design parameters and Properties:
- Maximum magnification(M) ; M = s/p
- Inter-sensor pitch (p)
- Active area width of an image sensor (s).
- Full-pitch resolution rpix= 2δ / M.(1.4-2.4 um)
- Also rpix= 2δp/s
- Number of micro-cameras.
We note that based on physical separation between each imaging module w.r.t. to each other, which decides the intersensor pitch(p), we can alter the imaging magnification and ensure continuous Field of View (FOV) imaging, as shown in the figure below.
Based on the above discussed parameters we arrive at three different configurations, namely the Multi View, Continuous and the Tiled. The tiled configurations ensures, complete field of view imaging by mechanical scanning across the sample.
Various MCAM configurations, in general s < p
Three different configurations for the MCAM: 2D diagram
Pixel limited resolution for the MCAM, plotted for different common pixel sizes of the sensor pixel
Configuration 1- Multi-View Imaging
- Each location is imaged by at least four unique micro-cameras.
- This allows for the usage of standard photogrammetry techniques, for jointly estimating sample height map along with composite image.
- MCAM configuration magnification:
- Maximum Full pitch resolution (rpix)= 8.8 um ( Approximately equal to the 1.25X microscope objective lens)
Configuration 2 – Continuous FOV Imaging:
- Field of View = Intersensor Pitch(p)
- Full pitch resolution: 1.4 um < rpix < 2um
(Resolution matching between 4x and 10 X objective lens with NA 0.15-0.3 range)
Configuration 3: Tiled high resolution imaging
- Full pitch resolution (rpix )= 1.1 um (Approximately equal to the 10x microscope objective lens)
- Higher resolution than the Multi-View Imaging and Continuous FOV imaging configurations.
Following table summarizes the specifications for all the three configurations of the MCAM.
- FOV refers to the imaging field of view
- Res, M, WD refer to the Optical resolution, Magnification and sample working distance, from the lens
- GP gigapixels per image composite