【作者】 刘旭；

【导师】 肖夏；

【作者基本信息】 天津大学 ， 微电子学与固体电子学， 2010， 硕士

【摘要】 乳腺癌已经成为了危害妇女健康的主要恶性癌症之一,对于患者越早被诊断出来,其存活率也就越高,乳腺癌的早期诊断也就成了拯救患者生命的关键所在。目前的早期乳腺癌诊断手段包括:乳房X光摄影、核磁共振和CT扫描等,尽管它们有着各自的优点,但它们的缺点,例如误检率高、分辨率低、对人体有着潜在的危险、费用较高等,这些缺点限制了它们作为乳腺癌早期普检的应用。目前,基于人体组织中正常乳腺组织与乳腺肿瘤组织之间在微波频段下的巨大电特性差(高达5:1的介电常数比和10:1的电导率比)的原理的超宽带微波成像技术被提出来,而这项技术具有很多适用于普检的优点,例如:精确、安全、成像方便、便宜、无痛、在满足足够的成像深度的条件下具有较高的成像分辨率。在本文中,建立了用来获取成像所需的散射信号的二维平面乳房模型,通过时域有限差分方法原理来模拟电磁波在模型中的传播情况。为了与实际情况相符合,考虑了皮肤、乳腺组织、乳腺肿瘤和肋骨等的色散情况,而通过单极Debye模型来模拟实际乳房组织的电特性。特别是考虑在完美匹配层边界条件下单极Debye模型的传播方程。在本文中使用了两种成像方法:微波共焦成像算法和Capon波束形成算法。为了检验成像算法的成像效果,给出了一些成像例子。通过对这些例子的研究,证明了Capon波束形成算法的优越性。更多还原

【Abstract】 Breast cancer is becoming one of the primary malignant cancers which are harmful to women’s health. The early detection is very significant for long-term survival of the breast cancer patients. Now the most common breast cancer detection method such as X-ray mammography, MRI, CT, despite their advantages, there are some limitations and potential risk to limit its application as a regular screening for early breast cancer detection. Recently, the ultra-wideband (UWB) imaging technique for the breast cancer detection is developed intensively based on the high contrast in the electric properties of malignant tumor related to normal fatty breast tissue, which is approximately 5:1 in the relative dielectric constant and 10:1 in the conductivity at microwave frequencies. This technology has many obvious advantages such as accurate, safe, inexpensive, sensitive, and painless and it can provide both the enough imaging resolution and the adequate penetration depth in the breast.In this paper, the two-dimensional planar breast model for obtaining the data is demonstrated. The microwave propagation in the breast is simulated by the finite difference time domain method (FDTD). The dispersive properties of the normal breast fatty, the skin, the tumor, and the chest wall are taken into consideration by single pole Debye model to approach the real electrical properties of the breast. Especially the Perfectly matched layer absorption boundary condition (PML ABC) in the case of single pole Debye model is taken into consideration.Two imaging algorithms are introduced, confocal microwave imaging and Capon beamforming imaging. Some examples are proposed to verify the imaging algorithms are correct. By studying these examples, the superiority of the Capon beamforming imaging algorithm is manifested.更多还原