Design of Automated Moving Stage with Adaptive Focus System to Support Microscopy Image Stitching

Image stitching is a method to obtain high-resolution images through compositing several image elements using invariant pattern recognizing and matching between each image elements involved. This method can remove resolution restriction in digital microscopy imaging. This study aims to design automated stitching with adaptive focus mechanism to achieve high-quality final stitched image. We attach three-axis microscopic actuator into Olympus CX-21 light microscope. The actuator has been programmed to support image elements capture with adaptive focus ability to compensate focus plane changes due to unevenness object surface, inhomogeneous slide thickness and imperfection of preparation holder. Testing results show automated moving stage has horizontal step resolution 0.198±0.001 μm/step with hysteresis 5.99±1.09 μm and vertical step resolution 0.197±0.004 μm/step with hysteresis 2.36±1.28 μm at maximum speed 3,675μm/sec in 16 sub-division microstep setting value. Automated moving stage has also linear response with R2=0.999. Adaptive focus testing show satisfied optimum objective height locking stability using identical factor ε=95% for every objective application below 100x. Adaptive focus success stabilizes Zopt for every image element to generate final stitched image with homogenous focus value.