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268 results on '"Ru, Changhai"'

7. Robotic denudation of zygotes

Author

Zhai, Rongan, primary, Shan, Guanqiao, additional, Dai, Changsheng, additional, Hao, Miao, additional, Wang, Yong, additional, Liu, Na, additional, Ru, Changhai, additional, and Sun, Yu, additional

Published
2023
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19. Automated Denudation of Oocytes

Author

Zhai, Rongan, primary, Shan, Guanqiao, additional, Dai, Changsheng, additional, Hao, Miao, additional, Zhu, Junhui, additional, Ru, Changhai, additional, and Sun, Yu, additional

Published
2022
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26. Robotic Blastocyst Biopsy

Author

Shan, Guanqiao, primary, Dai, Changsheng, additional, Liu, Hang, additional, Wang, Xian, additional, Dou, Wenkun, additional, Ru, Changhai, additional, Zhang, Zhuoran, additional, and Sun, Yu, additional

Published
2022
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30. Robotic Blastocyst Biopsy

Author

Shan, Guanqiao, Dai, Changsheng, Liu, Hang, Wang, Xian, Dou, Wenkun, Ru, Changhai, Zhang, Zhuoran, and Sun, Yu

Abstract

Soft tissue cutting is used for incision, separation and removal of tissues or cells. Due to the high deformation of soft tissues resulting from their viscoelasticity, it is challenging to accurately cut the tissue along a desired path and control the force applied to the tissue for reducing invasiveness, especially at the microscale. This paper presents a robotic biopsy system for cutting and collecting trophectoderm (TE) cells from a blastocyst (Day 5 embryo). The system, for the first time, enables TE cell junction detection for laser ablation throughout the blastocyst biopsy process by using U-Net with a modified Dice loss. A dynamics model taking into account cell mechanical properties was established to describe the motion of the TE cells inside a biopsy micropipette. Based on the model, an integral-based adaptive control method was developed for TE cell aspiration and positioning inside the biopsy micropipette. Experimental results revealed that the controller was capable of effectively compensating for the cell positioning error by updating the varying system parameters according to the update law. The biopsy success rate was 100% and the average biopsy time is 25 s. Compared to manual blastocyst biopsy, the robotic biopsy system reduced the necessary number of laser pulses ($\sim$5 vs. $\sim$7), reduced the number of lost nuclei in the collected TE cells (8% vs. 36%), and shortened the blastocyst.s recovery time (35 min vs. 50 min), indicating lower invasiveness to both the blastocyst and the collected TE cells.

Published
2023
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31. Automated Orientation Control of Motile Deformable Cells

Author

Dai, Changsheng, Shan, Guanqiao, Liu, Xingjian, Ru, Changhai, Xin, Liming, and Sun, Yu

Abstract

Automated manipulation of deformable objects is challenging due to the object’s deformation behavior. Different from still deformable objects such as wires and cloth, biological organisms such as sperm and worms are both deformable and motile, requiring the control of both deformation and motion. This paper reports automated orientation control of live sperm, as an example of motile deformable cells. Robotic manipulation of human sperm was performed by using a glass micropipette, which is a standard clinical tool, to rotate individual motile sperm. Sperm rotation must be performed before immobilization, as required in clinical cell surgery for infertility treatment. To control tail deformation during sperm rotation, a path planner was designed based on kinematic analysis and manipulation point update. To deal with the intrinsic motion of a motile sperm, a motorized stage was controlled to compensate for sperm swimming motion, and an observer was designed to decouple sperm orientation from its wiggling motion. A sliding mode controller was designed to cope with stiffness variances along the sperm tail and among different sperm. Deep neural networks were developed for robust sperm tail detection, and Kalman filter was used to predict tail motion. Experimental results demonstrated that automated sperm manipulation achieved an orientation error of 0.8° and operation time of 6.8 s, both significantly less than those of manual operation. The designed observer was effective to reduce sperm orientation error by reducing the disturbance from sperm wiggling motion. The developed sliding mode controller outperformed the PID controller in operation time, reducing the time of oocyte exposure to the ambient environment. Note to Practitioners—This work tackled the challenge of rotating a fast-swimming and deformable sperm in clinical cell surgeries. Automated manipulation of deformable objects has wide applications in industrial and service settings such as manipulating wires and folding cloth. However, the intrinsic motion of a motile sperm and the lack of a rotational degree of freedom in standard micromanipulators pose difficulties to automated sperm manipulation. In this paper, we propose automation techniques for sperm orientation control. For sperm tail detection, deep learning was used to handle the variances of shape and length among different sperm. A path planning strategy and a controller were designed to achieve automated rotation of motile sperm, with its deformation and motion both controlled. The developed methods can be generalized to the manipulation of other deformable objects such as wires, cables and cloth. These objects exhibit significant variance of mechanical properties, and calibration is often time-consuming. The designed controller can be used to manipulate deformable objects with robustness to varied mechanical parameters. Path planning was designed by updating the manipulation point based on the object’s deformation behavior, and is suitable in manipulation where constraints are imposed such as the object’s strain.

Published
2023
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