Discipline: Technology and Engineering
Subcategory: Biomedical Engineering
Brianna Williams - North Carolina A&T State University
Co-Author(s): Dr. Sun Yi, North Carolina A&T State University, Greensboro, NC
Human Immunodeficiency Virus (HIV) has become a prevalent issue in society for some time now. It is a virus that attacks the T-cells or lymphocytes of the body, keeping the immune system from functioning properly. The goal of the research is to keep these T-cell level counts as normal as possible to extend the life span of HIV-infected patients. The infection has many unique features to it that researchers and scientists attempt to uncover. For example, the lag that exists between when an infection enters the cell and the onset of Acquired Immunodeficiency Disease(AIDS), and how antiretroviral drugs are given to HIV-infected patients to help reduce the virus present in their bodies are intensively being investigated by them. Mathematical models of the infection will help uncover these features by parameter estimation techniques and sensitivity analysis. These math models will not only uncover hidden features of HIV, but they will help prevent AIDS, which is the most harmful stage of HIV. Throughout this research, vivo HIV patient data from five patients was studied. These patients had been given 600 mg of protease inhibitor drug twice daily, and over the course of time, it was evident whether the presence of an antiretroviral drug was reducing the viral load in the patient’s blood or not. An ordinary differential equation solver (ode45) in MATLAB was used to generate a code for the solution curves. The ode45 MATLAB function serves to solve differential equations with high accuracy and efficiency. The MATLAB solution curves became very useful when creating the mathematical model that we aimed to get out of the whole research experiment. To assess the model, parameters were changed to improve the accuracy of model and analyze for sensitivity as parameter values changed. When attempting to reduce viral loads, the sensitivity analysis process became vital when altering parameter values to study which data sets respond with a quicker viral decay. Sensitivity analysis plays an important role in this research by having the ability to change vital parameters that affect how much of a drug should be given for HIV patients. Based on results of numerical simulation, the patients are more sensitive to the change in delta rather than change in ‘c’ parameter. These results also show that using the ode45 solver creates more efficient viral decay than using other MATLAB solvers. In this study, features such as delays, drug therapy and sensitivity of HIV were assessed throughout a cell. This research proved that different magnitudes of drug and intensity of parameters have different effects on each patient. Introducing inhibitor drugs, such as protease, added to the system and helped reduce the viral load in patients. Changes in parameters were put in place to see which produced more efficient treatment by the thought of sensitivity analysis being used for various purposes including improved estimation of parameters and model validation. Further, it is now possible to plan drug administration, and eventually find better treatment of HIV. In the future, quantitative data analysis of the models produced should be taken into consideration to improve accuracy of the results. This means measuring the slope of the models to better predict whether certain parameter values truly reduced viral loads the best. Also, the system identification toolbox in MATLAB could be used to provide more accurate parameter estimation and enhance the research. Viral dynamics and this approach could be applied to other viruses/infections other than HIV to examine that process, and compare the results to each other. Keywords *: HIV-1, viral dynamics, mathematical modeling, sensitivity analysis.Not Submitted
Funder Acknowledgement(s): I would like to acknowledge the National Science Foundation(NSF) grant # ACI-1560385 and North Carolina A&T State University for sponsoring my research project.
Faculty Advisor: Dr. Sun Yi, firstname.lastname@example.org
Role: I did everything associated with the research including producing the data and creating the written report.