本文關(guān)鍵詞：動脈瘤射頻導(dǎo)管消融中多物理場耦合的計算與實驗研究　出處：《北京工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 動脈瘤 射頻消融 溫度場 有限元仿真

【摘要】：動脈瘤作為一種常見而危險的心腦血管疾病是醫(yī)學(xué)領(lǐng)域的研究熱點,特別是復(fù)雜動脈瘤的治療是一個富有挑戰(zhàn)性的醫(yī)學(xué)問題。近年來動脈瘤的介入治療術(shù)以其創(chuàng)傷性小、費(fèi)用低、療效好等特點已被廣泛應(yīng)用于臨床。但對于復(fù)雜的動脈瘤,介入治療會出現(xiàn)支架脫落、生物相容性問題及動脈瘤破裂等嚴(yán)重的并發(fā)癥。射頻導(dǎo)管消融是將很細(xì)的導(dǎo)管從頸部、大腿根部植入血管內(nèi),到達(dá)心臟等靶組織,然后釋放射頻電流,從而對“病灶”進(jìn)行一次性的消融。本課題將介入式熱療方法和動脈瘤栓塞機(jī)理結(jié)合起來,基于射頻導(dǎo)管消融術(shù)提出了一種新的方法治療動脈瘤,即采用射頻導(dǎo)管消融使動脈瘤瘤腔內(nèi)的血液快速凝固,形成血栓,阻止血液流向動脈瘤腔內(nèi),進(jìn)而逐步纖維化,最終導(dǎo)致動脈瘤萎縮,從而達(dá)到治療動脈瘤的目的。為了證明該方法的可行性,本研究通過有限元數(shù)值仿真和離體模型實驗兩種方法進(jìn)行驗證。在二維和三維模型的情況下進(jìn)行數(shù)值研究,分別研究了不同治療參數(shù)(包括不同激勵方式、電極形狀、消融方式等)對動脈瘤射頻消融的溫度場、流場的影響,分析消融范圍是否適合動脈瘤的治療。數(shù)值仿真的結(jié)果表明:在直管動脈瘤三維模型中,溫度場呈圓形,在加熱200s,電場強(qiáng)度為15V/mm時,最高溫度為101.52℃,動脈瘤腔的絕大部分都被60℃輪廓圖所包圍,但動脈瘤左側(cè)的小范圍的動脈壁與組織也被60℃輪廓圖所涵蓋,可能會造成小范圍的組織損傷。電極存在時,血管內(nèi)有電極處的血流速度升高0.04m/s左右,無電極處的流場速度降低0.1 m/s左右。瘤腔內(nèi)的流速較低有利于動脈瘤瘤腔內(nèi)溫度升高,60℃輪廓圖的形狀有利于動脈瘤腔內(nèi)的血液凝固,這從溫度場與流場兩個方面證明射頻消融治療動脈瘤的可行性。同時本研究利用三維打印構(gòu)建了理想的三維模型,經(jīng)過二次倒模得到透明的三維模型。利用微波消融儀自帶的水泵創(chuàng)建循環(huán)系統(tǒng),進(jìn)行離體模型實驗,觀察動脈瘤的溫度上升狀況。研究表明,當(dāng)天線在動脈瘤口頸處時,瘤腔內(nèi)溫度上升較小,在40W和60W,5min時,都約為1.6℃左右;80W時上升高于4℃。當(dāng)天線在動脈瘤腔內(nèi)時,瘤腔內(nèi)的溫度上升較快,在40W,5min時,為8℃左右,并且隨功率的升高,溫升變化不大。當(dāng)天線在動脈瘤腔內(nèi)時,在三種功率下溫度都上升11℃左右,溫度上升較大,有利于動脈瘤的消融。本研究表明類圓形的動脈瘤適合利用射頻消融方法進(jìn)行治療,且在激勵為15V/mm,消融時間為200s時,溫度場既能覆蓋整個動脈瘤又對外部組織損傷較小且對動脈內(nèi)的血流動力學(xué)狀況影響較小,可以作為動脈瘤射頻消融的最優(yōu)治療參數(shù)。在載瘤動脈為彎管時及囊狀動脈瘤時,可以利用射頻消融聯(lián)合支架來進(jìn)行動脈瘤的治療。
[Abstract]:As a common and dangerous cardiovascular and cerebrovascular disease, aneurysm is a hot topic in the field of medicine. In particular, the treatment of complex aneurysms is a challenging medical problem. In recent years, interventional treatment of aneurysms is less traumatic and less costly. The characteristics of good curative effect have been widely used in clinic, but for complex aneurysms, stent shedding will occur after interventional therapy. Serious complications such as biocompatibility and ruptured aneurysms. Radiofrequency catheter ablation (RFCA) is the implantation of a very thin catheter from the neck and the root of the thigh into the blood vessel to reach the target tissue such as the heart and then release the radiofrequency current. In this paper, we combine interventional hyperthermia with the mechanism of aneurysm embolization, and propose a new method for the treatment of aneurysm based on radiofrequency catheter ablation. That is, radiofrequency catheter ablation can rapidly coagulate the blood in the aneurysm cavity, form thrombus, prevent the blood flow into the aneurysm cavity, and then gradually fibrosis, and finally cause the aneurysm atrophy. In order to prove the feasibility of this method, the treatment of aneurysm can be achieved. This study was verified by finite element numerical simulation and in vitro model experiment. In the case of 2D and 3D models, different treatment parameters (including different excitation modes) were studied. The effect of electrode shape and ablation method on the temperature field and flow field of radiofrequency ablation of aneurysms is analyzed. The numerical simulation results show that the ablation range is suitable for the treatment of aneurysms. The temperature field is circular. When the heating time is 200 s and the electric field intensity is 15 V / mm, the highest temperature is 101.52 鈩，

本文編號：1360756