醫(yī)學(xué)數(shù)據(jù)可視化及軟組織建模
軟件工程 黃鵬飛 指導(dǎo)教師 顧力栩
【摘要】 自百年前倫琴發(fā)現(xiàn)X 射線以來,醫(yī)學(xué)圖像可視化經(jīng)歷了革命性的發(fā)展。醫(yī)學(xué)知識、物
理概念、數(shù)學(xué)方法和計(jì)算機(jī)科學(xué)理論有機(jī)地融合在醫(yī)學(xué)圖像處理之中。醫(yī)學(xué)虛擬現(xiàn)實(shí)是計(jì)算機(jī)科學(xué)
家孜孜不倦的追求。近年來,人體器官軟組織的三維建模更是計(jì)算機(jī)圖形學(xué)的重要研究課題。而軟
組織建模是實(shí)時(shí)手術(shù)虛擬和人機(jī)交互的基礎(chǔ)。
本文提出并討論了質(zhì)點(diǎn)彈簧算法,它將形變物體表面建模成質(zhì)點(diǎn)彈簧網(wǎng)絡(luò),其計(jì)算量小,但是
算法精度不高。然后介紹了中心線描繪算法,這種新型算法通過中心線信息對表面進(jìn)行重繪,從而
模擬形變,常被用作圖像的分割、配準(zhǔn)。雖然它的實(shí)時(shí)性不是很理想,但是它重繪的思路在軟組織
建模中頗有價(jià)值。于是,筆者結(jié)合了簡化了的中心線描繪模型與質(zhì)點(diǎn)彈簧模型,即在物體主要受力
形變區(qū)域采取質(zhì)點(diǎn)彈簧模型,在其它區(qū)域采取中心線描繪模型。這樣既保證了局部形變的實(shí)時(shí)性,
同時(shí)也保證了全局形變的逼真性。由于醫(yī)學(xué)數(shù)據(jù)可視化是軟組織三維建模的前提,本文還將介紹可
視化相關(guān)的三維重建、圖像分割算法等問題。除了核心的三維建模部分,本文亦將介紹人機(jī)交互技
術(shù)、力反饋、碰撞檢測、實(shí)時(shí)性與精確性等手術(shù)虛擬相關(guān)問題。
【關(guān)鍵詞】 醫(yī)學(xué)圖像 網(wǎng)格 形變 質(zhì)點(diǎn)彈簧 中心線描繪
【Abstract】 Since 100 years ago, when Roentgen discovered x-rays, medical image visualization has
revolutionarily developed. Medicine knowledge, physics concept, mathematics method and computer
science have interdisciplinarily worked together on the medical image processing. It is inherent for the
computer scientists to simulate the medical reality. In recent years, the 3D modeling of human organic
soft tissue has been an important research subject in computer graphics. And the soft tissue modeling is
the basis for the real-time surgery simulation and human computer interaction.
In this paper, we propose and discuss the mass-spring algorithm. It models the surface of deformable
object as the network of masses and springs. Its computational complexity is low but it is limited in
accuracy. And we propose a latest algorithm, medial representation. It redraws the surface based on the
centerline information to model the deformation and it is often used for image segemantation and
registration. Although its real-time property is not ideal enough, we can take advantage of its redrawing
strategy in soft tissue modeling. Therefore, we combine the mass-spring and medial representation
models so that we can achieve the real-time performance of local deformation and, at the same time, the
accuracy of entire deformation. Because medical data visualization is the precondition for soft tissue
modeling, we introduce the relating contents of 3D reconstruction and image segmentation. Besides 3D
modeling, which is the core part of surgery simulation, we also introduce the simulation’s relating issues
including human computer ineraction technique, force feeback, collision detection, accuracy and
real-time performance.
【Keywords】 Medical Image Mesh Deformation Mass-Spring Medial Representation
醫(yī)學(xué)數(shù)據(jù)可視化及軟組織建模
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目錄
醫(yī)學(xué)數(shù)據(jù)可視化及軟組織建模 1
1 引言 3
1.1 研究背景····························································································· 3
1.2 研究目標(biāo)····························································································· 3
1.3 內(nèi)容組織····························································································· 3
2 醫(yī)學(xué)數(shù)據(jù)可視化技術(shù) 3
2.1 概述····································································································· 3
2.2 醫(yī)學(xué)數(shù)據(jù)三維重建·············································································· 3
2.2.1 醫(yī)學(xué)圖像數(shù)據(jù)格式······························································· 3
2.2.2 表面繪制技術(shù)······································································· 3
2.2.3 體繪制技術(shù)··········································································· 3
2.3 醫(yī)學(xué)圖像分割······················································································ 3
2.3.1 形態(tài)學(xué)方法··········································································· 3
2.3.2 快速步進(jìn)法··········································································· 3
2.4 醫(yī)學(xué)可視化平臺開發(fā)實(shí)現(xiàn)·································································· 3
2.4.1 VTK 軟件開發(fā)包···································································· 3
2.4.2 ITK 軟件開發(fā)包···································································· 3
2.4.3 Atamai 手術(shù)導(dǎo)航軟件開發(fā)包·············································· 3
2.4.4 基于Atamai 的醫(yī)學(xué)可視化平臺········································· 3
3 三維物體表面網(wǎng)格化技術(shù) 3
3.1 概述····································································································· 3
3.2 VTK 數(shù)據(jù)格式···················································································· 3
3.3 行進(jìn)立方體算法·················································································· 3
3.4 氣球算法····························································································· 3
4 人體軟組織三維建模 3
4.1 概述····································································································· 3
4.2 質(zhì)點(diǎn)彈簧算法······················································································ 3
4.2.1 質(zhì)點(diǎn)彈簧拓?fù)浣Y(jié)構(gòu)······························································· 3
4.2.2 質(zhì)點(diǎn)彈簧系統(tǒng)原理······························································· 3
4.2.3 表面模型··············································································· 3
4.2.4 體模型··················································································· 3
醫(yī)學(xué)數(shù)據(jù)可視化及軟組織建模
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4.3 中心線描繪算法·················································································· 3
4.3.1 中心線幾何結(jié)構(gòu)··································································· 3
4.3.2 根據(jù)中心線繪制表面··························································· 3
4.4 質(zhì)點(diǎn)彈簧算法與中心線描繪算法的結(jié)合·········································· 3
4.5 三維建模應(yīng)用程序開發(fā)實(shí)現(xiàn)······························································ 3
5 醫(yī)學(xué)虛擬現(xiàn)實(shí) 3
5.1 概述····································································································· 3
5.2 交互作用技術(shù)······················································································ 3
5.2.1 三維圖形坐標(biāo)選取······························································· 3
5.2.2 碰撞檢測··············································································· 3
5.2.3 力反饋··················································································· 3
5.3 實(shí)時(shí)性與真實(shí)性·················································································· 3
結(jié)論與展望 3
謝辭 3
主要參考文獻(xiàn) 3
附錄 3
醫(yī)學(xué)數(shù)據(jù)可視化及軟組織建模
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1 引言
1.1 研究背景
醫(yī)學(xué)圖像處理與分析技術(shù)涉及很多學(xué)科,包括計(jì)算機(jī)圖像處理、計(jì)算機(jī)圖形學(xué)、
模式識別、虛擬現(xiàn)實(shí)以及醫(yī)學(xué)相關(guān)知識等。
關(guān)于醫(yī)學(xué)圖像的發(fā)展,是德國物理學(xué)家倫琴開創(chuàng)了人體圖像的先河。1895 年11
月8 日,倫琴在研究時(shí)無意中發(fā)現(xiàn)了X 射線, |
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