Precision ZP Perforation Automation: A Vision-Based Robotic Approach for Blastocyst Embryo Biopsy

Abstract

Microsurgical operations such as embryo biopsy require extracting a material sample from inside the embryo for genetic testing. A precise perforation for embryo zona pellucida (ZP) is required to permit access for the biopsy micropipette to extract the sample. Many approaches have been developed for the ZP perforation, such as mechanical, chemical, and photothermolysis (the laser). This paper presents an automatic method for the blastocyst embryo ZP perforation. This method utilizes a conventional laser system currently in use in manual approaches in research labs and in-vitro fertilization clinics and controls the whole perforation process using a vision feedback system. An experimental setup is developed to verify the behavior of the proposed method, in which a holding micropipette is used to hold and move the embryo, which is then moved in two coordinate directions toward the laser spot location. A computer vision algorithm is used to estimate the embryo ZP thickness to tune the laser parameters and estimate the ZP circle median quadrant coordinates. Then use this information as a feedback signal to a simple proportional controller to control the embryo motion. Experimental results demonstrate that the system is capable of embryo relocation and ZP perforation.