Date of Completion
Tai-Hsi Fan; Mehmet Toner; Robert Gao
Field of Study
Master of Science
ICSI (intra-cytoplasmic sperm injection) has attracted research interest from both biological and engineering groups. The technology is constantly evolving to perform this procedure with precision and speed. One such development is the contribution of this thesis. We focus on a relatively recent procedure called Ros-Drill© (rotationally oscillating drill), of which the early versions have already been effectively utilized for the mice. In the first part, we present a procedure to automate a critical part of the operation: initiation of the rotational oscillation, Visual feedback is used to track the pipette tip. Predetermined species-specific penetration depth is successfully utilized to initiate the rotational oscillation command. Penetration-depth-based decisions concur with a curvature-based approach. In the second part for the automation we improve the performance of the rotational motion tracking.
Ros-Drill© is an inexpensive set-up, which creates high-frequency rotational oscillations at the tip of an injection pipette tracking a harmonic motion profile. These rotational oscillations enable the pipette to drill into cell membranes with minimum biological damage. Such a motion control procedure presents no particular difficulty when it uses sufficiently precise motion sensors. However, size, costs and accessibility of technology on hardware components may severely constrain the sensory capabilities. Then the trajectory tracking is adversely affected. In this thesis we handle such a practical case, and present hardware and software improvements using a commonly available microcontroller and extremely low-resolution position measurements. Biological tests are performed and it is confirmed that the mechanical structure plays a crucial role for success.
Diaz, Jhon F., "Ros-Drill Automation: Visual Feedback Control And Rotational Motion Tracking" (2011). Master's Theses. 136.