Development of a Vision-Based Robotic Manipulation System for Transferring of Oocytes

Embryos/oocytes vitrification is an essential cryopreservation technique in IVF (in vitro fertilization) clinics. The reliable and effective transferring of embryos/oocytes is crucial to the subsequent steps in the whole procedure of vitrification. After each transferring, the straw needs to be replaced with a new one. Due to the uncertainties in the fabrication and installation, the exact knowledge of the kinematic model of the straw is usually unknown, and the relationship between the microscope and the straw is also unknown without calibration beforehand. In such situation, automatically transferring the oocytes from micropipette to the narrow tip of straw (0.7mm) is very challenging. In this paper, a new vision-guided robotic system is developed to automate the transferring of the oocyte without calibration. To this end, the unknown depth information is estimated then compensated by constructing a deep vision network through microscope image, and an approximate Jacobian control algorithm is also proposed to servo control the end tip of the uncalibrated straw to contact the micropipette with the vision feedback. After that, the oocyte is automatically transferred from the micropipette to the straw to finalize the task. The stability of the closed-loop control system is rigorously proved with Lyapunov methods, and the effectiveness of the developed robot is validated in experiments.