Fast Volumetric Imaging with Line-scan Confocal Microscopy by an Electro-tunable Lens

Abstract

Rapid and volumetric imaging has stayed as a significant challenge in imaging biological tissue techniques and visualizing neuronal activities. Yet, when using any varifocal lens conjugated with the back focal plane of the objective lens can result in 3D imaging in any microscopy system but it is required for the complication in the system or the tradeoff between the image resolution or speed of the image. In this study, we present a combination between the electrical tunable lens (ETL) and simple line-scan confocal microscopy to solve both of the issues. The scientific CMOS camera was used in rolling shutter mode as a line-detector in continuous to achieve volumetric imaging at speed 40 frame/s. The resolution in the axial direction of the 3D line-scan confocal microscopy system was measured with the 0.5μm fluorescent bead was 7.5 μm and 83.2 μm when the ETL is off and on, respectively with 20X objective lens. Our line-scan microscopy system can achieve the speed in volumetric imaging is at a video rate of 40 volumes per second (vps) in 141x120x106 μm3 in the clear sample. For in vivo mouse brain, our system can go for 141x120x50 μm3 in the same imaging speed. This confocal microscopy system can be helpful in not only visualizing biological structures such as neurons but also for blood vessel tracking.