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Hajati, Nasim

University of British Columbia

Assessing the performance of the cardiovascular system is a crucial part of testing new medications and biomedical devices. To ensure the safety of these new products, it is necessary that their impact on performance factors, such as the strength or elasticity of the heart muscles be evaluated. These tests are typically performed on animals; specifically, rodents have been playing a significant role in such biomedical experimentations. Traditional methods of studying the cardiovascular system involve invasive surgeries to reach the heart and its vessels, to manually manipulate the blood return flow to the left ventricle and monitor the change in the patterns of ventricular or arterial pressure and volume through plotting pressure-volume graphs. These surgical methods often lead to blood loss or damage to vessels and organs of the rodents, which affects the test results, making them less accurate. They are also subject to human error which leads to low repeatability. Considering the issues of the traditional approaches, the literature suggests using a manually-operated Lower Body Negative Pressure (LBNP) chamber as a non-invasive alternative. This approach places sealed chambers around the lower body of the rodents and creates suction inside the chamber to control the blood flow to the heart by drawing the blood toward the lower body as an effect of the negative pressure. To remove direct human intervention, an automated servo-controlled system was built by previous UBC students, which controlled the blood pressure level, to be later plotted against the measured volume. This study aims to fix the shortcomings of that device, including low interface speed and lack of safety features for the electronics. In addition, this study performs system identification on the automated chamber and rodents’ left ventricular pressure models and designs a robust controller for the system based on the derived models.

Text; Still Image

2024-04-22

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/87913

Electrical Engineering

University of British Columbia

UBCO

http://creativecommons.org/licenses/by-nc-nd/4.0/