Diagnosis of Cardiovascular Diseases via System Identification of Tube-Load Model

  • Author / Creator
    Ebrahimi Nejad, Shiva
  • Cardiovascular diseases, affecting the heart and the arteries are the leading cause of morbidity and mortality in the world. Many forms of these diseases begin and develop asymptomatically. Cardiovascular patients often not aware of the condition until later stages when the treatments are more invasive and costly. To overcome this problem, many medical researchers suggest using an active screening process for the primary diagnosis of cardiovascular diseases. This is specifically intended for patients with higher cardiovascular risk factors. However, this would not be possible without having an effective diagnostic method. This study focuses on the diseases affecting the arteries, specifically peripheral artery disease (peripheral atherosclerosis) and arterial stiffening (arteriosclerosis). The current primary diagnosis method for these diseases includes a risk assessment, the ankle brachial index, and the flow mediated dilatation test. Although the existing methods have many advantages, they are also known to have limitations. In order to overcome the drawbacks of these methods, this research pursued a novel method of diagnosis by applying wave analysis. This method is based on a mathematical model of the arterial tree, referred to as “tube-load model”, which simulates the arterial tree using a few easy to understand parameters, each representing a different characteristic of the arterial system. The aforementioned diseases affect the properties of the cardiovascular system in a specific way, such as narrowing the luminal area or stiffening of compliant arteries. Since the parameters of the tube-load model reflect the characteristics of the arterial tree, analysing its parameters is a potential method to detect diseases in the arterial system. In order to develop the diagnosis approach, the effects of the arterial diseases and arterial stiffening on the arterial tree were studied, first. Secondly, by considering the definition of each of the parameters of the tube-load model, the behavior of the tube-load parameters under these conditions were determined. In order to validate the method, different cases of peripheral artery disease and arterial stiffening were simulated using a high-fidelity model of the arterial tree. Pressure waveforms were then used to evaluate the parameters of the tube-load model. By comparing the parameters of diseased versus normal arterial tree simulations, the proposed diagnosis method was validated. In the next step, the sensitivity of the parameters of the tube-load model to the geometry of peripheral artery blockages were investigated. Moreover the parameter of tube-load model were used to determine the increase in the peripheral resistance. Based on the results, the tube-load model is reliable and is a promising field for future study.

  • Subjects / Keywords
  • Graduation date
    Fall 2015
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
  • Supervisor / co-supervisor and their department(s)
  • Examining committee members and their departments
    • Carey, Jason (Mechanical Engineering)
    • Hahn, Jin-Oh (Mechanical Engineering)
    • McMurtry, Sean (Medicine)
    • Raboud, Don (Mechanical Engineering)