In-plane and Out-of-plane Visual Feedback Solution for Automated Zebrafish Larvae Microinjection System

Microinjection for Zebrafish heart is one of the most efficient methods to transfer foreign materials into Zebrafish circulation system. Automated microinjection for Zebrafish heart not only reduces personal involvement during the operation, but also frees technicians from laborious and time-consuming work. However, traditional visual-based detections are in two-dimensions, lacking the precise vertical measurement manner for three-dimensional spatial accessibility. Further, the application of the force sensors would lead to complicated mechanical structure to the end-effectors and are extremely sensitive to noise. Moreover, the contour of the heart is irregular and is difficult to capture, compared to contours of cells and embryos. To overcome these challenges, this paper proposed a reinforced approaching motion detection method for three-dimensional Zebrafish heart detection. The proposed method is composed of two parts, the in-plane heart detection and the approaching motion detection. A local-enhanced consecutive-frame motion-accumulated in-plane motion detection is developed for 2D heart locolization. The height detection of the heart is achieved with the injection pipette approaching the detecting area. The reinforced approach motion detection algorithm is verified not only on the Zebrafish heart area, but also on other important areas, such as brain, ear, tail muscle, and yolk. Experimental results demonstrate the enhanced accuracy, efficiency, and lowered computation time of the tailored visual solutions, which can significantly contribute to the microinjection automation.