Automated Vitrification of Embryos: A Robotics Approach

Abstract

This article reports on the first robotic system for vitrification of mammalian embryos. Vitrification is a technique used for preserving oocytes and embryos in clinical in vitro fertilization (IVF). The procedure involves multiple steps of stringently timed pick-and-place operation for processing an oocyte/embryo in vitrification media. In IVF clinics, the vitrification is conducted manually by highly skilled embryologists. Processing one oocyte/embryo takes the embryologist 15-20 min, depending on the protocols chosen to implement. Due to poor reproducibility and inconsistency across operators, the success and survival rates also vary significantly. Through collaboration with IVF clinics, we are in the process of realizing robotic vitrification (RoboVitri) and ultimately aim to standardize clinical vitrification from manual operation to fully automated robotic operation. Our robotic system is embedded with two contact detection methods to determine the relative z positions of the vitrification micropipette, embryo, and vitrification straw. A three-dimensional (3-D) tracking algorithm is developed for visually served embryo transfer and real-time monitoring of embryo volume changes during vitrification. The excess medium is automatically removed from around the vitrified embryo on the vitrification straw to achieve a high cooling rate.