本文選題：柔性組織變形 + 柔性針穿刺��； 參考：《哈爾濱工業(yè)大學(xué)》2015年碩士論文

【摘要】：經(jīng)皮穿刺術(shù)是微創(chuàng)介入手術(shù)中一種重要的方法。傳統(tǒng)的經(jīng)皮穿刺術(shù)使用剛性針作為穿刺工具,但剛性針通常難以滿足穿刺過程中的避障要求,由此產(chǎn)生斜角柔性針。盡管柔性針軌跡十分靈活,但大曲率圓弧軌跡易造成人體組織撕裂,且針尖反復(fù)轉(zhuǎn)向產(chǎn)生的直線軌跡會(huì)造成組織挫傷。本文針對(duì)此問題,對(duì)柔性組織操控技術(shù)進(jìn)行研究,通過控制柔性組織變形使穿刺目標(biāo)靶點(diǎn)發(fā)生偏移,從而簡化穿刺軌跡并降低傷害。通常的柔性體變形控制方法要先對(duì)柔性體建模,這需要大量變形參數(shù),而人體組織通常是無先驗(yàn)知識(shí)目標(biāo)。對(duì)此,本文使用基于無標(biāo)定視覺伺服的柔性組織控制理論估計(jì)變形模型并進(jìn)行變形控制:通過對(duì)包含未知的柔性組織變形特征及攝像機(jī)投影模型的變形雅克比矩陣進(jìn)行估計(jì),得到系統(tǒng)的預(yù)估雅克比矩陣,并由預(yù)估矩陣通過速度控制器生成系統(tǒng)的變形控制速度使柔性組織變形,通過視覺檢測(cè)出實(shí)際變形特征與理論變形特征的誤差,反饋給估計(jì)器來修正預(yù)估雅克比矩陣。本文由李雅普諾夫第二法驗(yàn)證算法的穩(wěn)定性,并通過仿真實(shí)驗(yàn)分析算法各項(xiàng)指標(biāo)。本課題提出了針對(duì)柔性針穿刺的柔性組織變形控制方案。本文通過對(duì)柔性針進(jìn)行軌跡規(guī)劃,逆向推導(dǎo)出柔性組織靶點(diǎn)位移從而變形控制方案。柔性針穿刺軌跡種類較多,為解決平面的變形控制問題,本文對(duì)均勻組織中的平面圓弧穿刺軌跡進(jìn)行分析,提出復(fù)數(shù)障礙物約束條件下的軌跡求解方案,并建立評(píng)價(jià)函數(shù)來對(duì)穿刺軌跡進(jìn)行分級(jí)�？紤]到這是一個(gè)多目標(biāo)優(yōu)化問題,本文使用改進(jìn)的NSGA2遺傳算法求解,通過種群最優(yōu)面對(duì)于評(píng)價(jià)函數(shù)進(jìn)行修正,并最終通過權(quán)重系數(shù)將多目標(biāo)合成為單一評(píng)價(jià)函數(shù)并得到最優(yōu)穿刺軌跡,從而確立柔性組織變形控制方案。最后,本文對(duì)現(xiàn)有的圖像處理方法進(jìn)行分析比較,使用Open CV實(shí)現(xiàn)目標(biāo)檢測(cè)與跟蹤,并編寫了變形控制的軟件平臺(tái),包括視覺系統(tǒng)、機(jī)器人系統(tǒng)、控制系統(tǒng)等。本文提出的變形控制分為兩部分:一是根據(jù)具體環(huán)境,通過軌跡優(yōu)化求得目標(biāo)靶點(diǎn)位移方案,二是通過變形控制系統(tǒng)控制柔性材料達(dá)到預(yù)定變形目標(biāo)。通過對(duì)實(shí)驗(yàn)數(shù)據(jù)進(jìn)行分析,進(jìn)一步檢驗(yàn)控制理論,并驗(yàn)證變形控制系統(tǒng)的可行性。
[Abstract]:Percutaneous puncture is an important method in minimally invasive interventional surgery. The traditional percutaneous puncture uses rigid needle as puncture tool, but rigid needle is usually difficult to meet the requirements of obstacle avoidance in the process of puncture, resulting in oblique flexible needle. Although the flexible needle trajectory is very flexible, the arc trajectory with large curvature can easily lead to the tear of human tissue, and the straight line track caused by the repeated turning of the needle will cause tissue contusion. Aiming at this problem, this paper studies the flexible tissue manipulation technology, which makes the target deviation by controlling the deformation of the flexible tissue, thus simplifies the puncture trajectory and reduces the injury. The common deformation control method of flexible body is to model the flexible body first, which requires a large number of deformation parameters, while human tissue is usually no prior knowledge of the target. In this paper, the theory of flexible organization control based on uncalibrated visual servo is used to estimate the deformation model and control the deformation. The prediction Jacobian matrix of the system is obtained, and the deformation control speed of the system is generated by the predictive matrix through the velocity controller. The errors between the actual deformation characteristics and the theoretical deformation characteristics are detected by vision. Feedback is given to the estimator to modify the estimated Jacobian matrix. In this paper, the stability of the algorithm is verified by Lyapunov's second method, and the indexes of the algorithm are analyzed by simulation experiments. In this paper, a flexible tissue deformation control scheme for flexible needle puncture is proposed. In this paper, the target displacement of flexible tissue is derived by trajectory planning of flexible needle, and the deformation control scheme is derived. There are many kinds of flexible needle puncture trajectory. In order to solve the problem of plane deformation control, this paper analyzes the plane arc puncture trajectory in uniform organization, and puts forward the trajectory solution scheme under the condition of complex obstacle constraint. An evaluation function was established to grade the puncture track. Considering that this is a multi-objective optimization problem, an improved NSGA2 genetic algorithm is used to solve the problem. Finally, the multi-objective is synthesized into a single evaluation function through the weight coefficient, and the optimal puncture trajectory is obtained, thus the flexible tissue deformation control scheme is established. Finally, this paper analyzes and compares the existing image processing methods, uses Open CV to realize target detection and tracking, and compiles the software platform of deformation control, including vision system, robot system, control system and so on. The deformation control proposed in this paper is divided into two parts: one is to obtain the target target displacement scheme by trajectory optimization according to the specific environment, and the other is to control the flexible material to achieve the predetermined deformation target through the deformation control system. Through the analysis of experimental data, the control theory is further tested and the feasibility of deformation control system is verified.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：R616;TP273

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 陳定方;潘超;;彈性體建模仿真新方法[J];華中科技大學(xué)學(xué)報(bào)(自然科學(xué)版);2007年07期

相關(guān)碩士學(xué)位論文 前1條

1 張際超;斜角柔性針的非均勻介質(zhì)穿刺模型及針體實(shí)時(shí)監(jiān)測(cè)研究[D];哈爾濱工業(yè)大學(xué);2014年

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本文編號(hào)：1866283