Visual-based impedance force control of three-dimensional cell injection system

Biological cell injection is laborious work which requires lengthy training and suffers from a low success rate. Even a tiny excessive manipulation force can destroy the membrane or tissue of the biological cell. This makes the control of the injection force an important factor in the cell injection process. In this paper, a vision-based impedance force control algorithm is proposed based on dynamic modeling of a laboratory test-bed injection system. The injection force is calibrated in a cell injection task to derive the relationship between the force and the cell deformation. A cell biomembrane point-load model is utilized in this force calibration. In three-dimensional cell injection task, the total cell membrane deformation is estimated, based on the X - Y coordinate frame deformation of the cell, as measured with a microscope, and the known angle between the injector and the X - Y plane. Further, a relationship between the injection force and the injector visual displacement of the cell membrane is derived. Based on this force visual estimation scheme, an impedance force control algorithm is developed. Finally, experimental results are given which demonstrate the effectiveness of the proposed approach.