Tissue actuation studies for a digital-imaged elasto-tomogarphy [i.e. tomography] (DIET) breast cancer screening system. (2005)
Type of ContentTheses / Dissertations
Thesis DisciplineMechanical Engineering
Degree NameMaster of Engineering
PublisherUniversity of Canterbury. Mechanical Engineering
AuthorsKinoshita, Shigeakishow all
Breast cancer is now the second leading cause of cancer death for women around the world . However, in New Zealand, according to the “Cancer Society of New Zealand’, breast cancer still has the dubious leadership of being the leading cause of cancer death . There are no “clear opportunities for prevention”  but early detection and treatment can significantly reduce the risk of death from breast cancer. The Digital-Imaged Elasto-Tomography (DIET) screening system is by no means a substitute nor a replacement for the existing methods of detection. Instead, it is being developed to compliment existing methods in early and better detection of carcinomas in the breast. The DIET system relies on the differential stiffness contrast between the healthy and abnormal tissue. The concept is to use these differences in the modulus of the breast tissues (elastography) to determine the existence or non-existence of invasive carcinoma and the location and size of such tumour within the breast, if possible. The work presented in this thesis is a small portion of a broader project focused on the development of this novel breast cancer screening system. It attempts to carry out a finite element analysis using a commercial FEM package, Ansys, on a simplified computer model of a breast to assess the validity of the DIET system in detecting the existence of ductal carcinoma in-situ (DCIS) within a breast. Harmonic response analyses of simple computational model of a human breast is carried out and the results presented in this work. In particular, surface wave motion in terms of the steady-state displacement and phase shift angle in the primary axis of the actuation is examined. Results indicate that consistent surface motion pattern is seen with both the displacement and phase shift of the surface motion at lower range of frequencies. There are also indications that use of higher excitation frequency does not always guarantee good indication of the location of the breast.