基于光镊的斑马鱼体内单细胞自动运输系统研究

发布时间：2018-01-03 19:10

本文关键词：基于光镊的斑马鱼体内单细胞自动运输系统研究　出处：《中国科学技术大学》2017年博士论文　论文类型：学位论文

【摘要】：体内生物学研究,特别是活体体内研究,对观察生物体整体生命活动、验证体外研究结果至关重要。开发一种可以在体内捕获并操纵单细胞的工具可以极大地促进对生物体内活动的研究。体内单细胞运输作为体内细胞操作的基础,可以控制在体内实验中细胞的数目与位置,有助于观察在体内特殊环境中目标细胞的特性。光镊的手动操作实验证明了它有能力进行活体体内单一细胞操作。然而人工操控的能力有限,特别是在多扰动高不确定性的体内环境中进行生物微粒操控存在着很大的难度。本文采用机器人与光镊技术相结合的方法开发出了一种自动细胞运输系统,旨在自动识别、捕获和运输体内环境中的单细胞。本论文研究从以下三个方面展开。第一,为了实现体内目标细胞的自动识别与跟踪,建立了一套体内细胞跟踪系统。通过利用诸如背景分割、阈值分割和霍夫变换等图像处理技术,系统可以对复杂体内环境中细胞的位置进行辨识,然后基于细胞运动的位置相关性跟踪被辨识出的细胞,可实现目标细胞的实时跟踪。第二,为了实现体内单个目标细胞的自动运送,构建了一套自动细胞运输系统。该系统将检测到的细胞位置作为反馈信息,采用抗饱和比例控制器对光镊位置进行控制,实现了体内细胞的自动运输。在此基础上,进一步开发了一种扰动补偿控制器,以减小血液流动所产生的粘滞阻力对细胞运输所造成的影响。这种控制方法具有细胞运输轨迹可调、轨迹矫正、最小化稳态误差、消除超调等优点,适用于复杂的体内环境。仿真和实验证明了所提方法可以有效地对斑马鱼体内单个血红细胞进行运输。第三,开发了一种具有避障功能的扰动补偿控制器,以处理在体内细胞运输过程中的碰撞问题。碰撞是体内运输任务失败的主要原因之一。本文提出了一种碰撞规避矢量法,并结合扰动补偿控制器实现了细胞运输过程中的避障。这种方法可以在一个单一步骤中实现障碍物检测和碰撞规避策略制定,以此减少了在线运算量,同时提高了避障的效率。该方法可以使用不同的避障策略来适应不同的运输环境。仿真和实验验证了所提出的控制器的有效性。综上所述,本文提出了一种体内单细胞自动运输控制系统,实现了斑马鱼体内单细胞的精确跟踪,控制与避障。本研究可以应用于诸多生物学研究中,如药物靶向递送,体内细胞提取和癌症转移机制的探索等,为这些领域的研究发展提供了新的研究工具与手段。
[Abstract]:In vivo biological studies, especially in vivo studies, to observe the overall life activities of organisms. The development of a tool that can capture and manipulate single cells in vivo can greatly facilitate the study of biological activities in vivo. In vivo single cell transport is the basis of cell operation in vivo. The number and location of cells can be controlled in vivo. It is helpful to observe the characteristics of target cells in a special environment in vivo. The experiment of manual operation of optical tweezers proves that it has the ability to operate single cell in vivo. However, the ability of manual manipulation is limited. In particular, it is very difficult to control biological particles in the environment with high uncertainty. In this paper, an automatic cell transportation system is developed by combining robot with optical tweezers. The purpose of this paper is to automatically recognize, capture and transport single cells in vivo. The research in this paper is carried out from the following three aspects. First, in order to achieve automatic recognition and tracking of target cells in vivo. By using image processing techniques such as background segmentation, threshold segmentation and Hough transform, the system can identify the location of cells in complex internal environment. Then tracking the identified cells based on the position correlation of cell motion can realize the real-time tracking of target cells. Secondly, in order to realize the automatic transport of single target cells in the body. A set of automatic cell transportation system is constructed, which takes the detected cell position as feedback information and uses anti-saturation proportional controller to control the position of optical tweezers. On the basis of this, a disturbance compensation controller is developed. In order to reduce the effect of viscous resistance caused by blood flow on cell transport, this control method has the advantages of cell transport trajectory adjustable, trajectory correction, minimization of steady-state error, elimination of overshoot and so on. Simulation and experiments show that the proposed method can effectively transport a single red blood cell in zebrafish. Thirdly, a disturbance compensation controller with obstacle avoidance function is developed. In order to deal with the problem of collision in the process of cell transport in vivo, collision is one of the main reasons for the failure of transportation in vivo. In this paper, a collision avoidance vector method is proposed. This method can realize obstacle detection and collision avoidance strategy in a single step, thus reducing the amount of online operation. At the same time, the efficiency of obstacle avoidance is improved. In this method, different obstacle avoidance strategies can be used to adapt to different transportation environments. Simulation and experiments verify the effectiveness of the proposed controller. In this paper, a single cell automatic transportation control system in vivo is proposed, which can accurately track, control and avoid obstacles in zebrafish. This study can be used in many biological studies, such as drug targeting delivery. In vivo cell extraction and the exploration of cancer metastasis mechanism provide new tools and means for the research and development of these fields.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：Q2-33

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