Precise Cell Injection and Extraction Control Based on Microscopic Visual Feedback

Nuclear transplantation is an effective method for processing, modifying, and reconstructing cells, which is widely used in biological experiments. Microinjections and extractions are key steps in nuclear transplantation. It is beneficial to the promotion and the application of nuclear transplantation by increasing the efficiency and improving the quality of microinjections. At present, little research has been implemented for the speed/volume control problem in the microinjection process. Motivated by this observation, this article designs an update-law-improved adaptive control scheme to implement precise injections and extractions. Specifically, a precise mathematical model of the overall system is established first, which takes the imaging, pneumatic pump, cell, and micropipette elements into full consideration. Since parameters in the model are difficult to calibrate or measure, an update-law-improved adaptive control algorithm, together with a trajectory planner, is constructed for the microinjection and extraction system, which shows great tolerance to parameter uncertainties, avoids overshoot of the system to ensure great protection for the manipulated cells, and demonstrates fast convergence rate. The stability of the designed control system is proved theoretically by LaSalle's principle. Finally, the controller is tested by both numerical simulation and practical experiments, with the obtained data demonstrating satisfactory performances of the overall system.