Geometric characterization of cell membrane of mouse oocytes for ICSI.

Intracytoplasmic sperm injection (ICSI) is a broadly utilized assisted reproductive technology. A number of technologies for this procedure have evolved lately, such as the most commonly utilized piezo-assisted ICSI technique (P-ICSI). An important problem with this technique, however, is that it requires a small amount of mercury to stabilize the tip of the penetration micropipette. A completely different and mercury-free injection technology, called the rotationally oscillating drill (Ros-Drill) (RD-ICSI), was recently developed. It uses microprocessor-controlled rotational oscillations of a spiked micropipette after the pipette deforms the membrane to a certain tension level. Inappropriate selection of this initiation instant typically results in cell damage, which ultimately leads to unsuccessful ICSI. During earlier manual clinical tests of Ros-Drill, the technicians' expertise determined this instant in an ad hoc fashion. In this paper, we introduce a computer-vision-based tool to mechanize this process with the objective of maintaining the repeatability and introducing potential automation. Computer images are used for monitoring the membrane deformations and curvature variations as the basis for decision making. The main contribution of this paper is in the specifics of the computer logic to perform the monitoring. These new tools are expected to provide a practicable means for automating the Ros-Drill-assisted ICSI operation.