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Dynamic HIV/AIDS parameter estimation with Applications

Dissertation (MEng)--University of Pretoria, 2006.

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Other Authors: Xia, Xiaohua
Format: Thesis
Published: University of Pretoria 2013
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access_status_str Open Access
author2 Xia, Xiaohua
author_browse Xia, Xiaohua
author_facet Xia, Xiaohua
collection Thesis
dc_rights_str_mv © 2004, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MEng)--University of Pretoria, 2006.
format Thesis
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institution University of Pretoria (South Africa)
last_indexed 2026-06-10T12:39:30.899Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2013
publishDateRange 2013
publishDateSort 2013
publisher University of Pretoria
publisherStr University of Pretoria
record_format dspace
source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/25492 Dynamic HIV/AIDS parameter estimation with Applications Xia, Xiaohua s98014051@student.up.ac.za Filter, Ruben Arnold Dynamic parameter estimation Optimization and medical systems Parameter variation Viral set point estimation Dynamic systems Hiv/aids model parameters Bioengineering UCTD Dissertation (MEng)--University of Pretoria, 2006. This dissertation is primarily concerned with dynamic HIV/AIDS parameter estimation, set against the background of engineering, biology and medical science. The marriage of these seemingly divergent fields creates a dynamic research environment that is the source of many novel results and practical applications for people living with HIV/AIDS. A method is presented to extract model parameters for the three-dimensional HIV/AIDS model in situations where an orthodox LSQ method would fail. This method allows information from outside the dataset to be added to the cost functional so that parameters can be estimated even from sparse data. Estimates in literature were for at most two parameters per dataset, whereas the procedures described herein can estimate all six parameters. A standard table for data acquisition in hospitals and clinics is analyzed to show that the table would contain enough information to extract a suitable parameter estimate for the model. Comparison with a published experiment validates the method, and shows that it becomes increasingly hard to coordinate assumptions and implicit information when analyzing real data. Parameter variations during the course of HIV/AIDS are not well understood. The results show that parameters vary over time. The analysis of parameter variation is augmented with a novel two-stage approach of model identification for the six-dimensional model. In this context, the higher-dimensional models allow an explanation for the onset of AIDS from HIV without any variation in the model parameters. The developed estimation procedure was successfully used to analyze the data from forty four patients of Southern Africa in the HIVNET 28 vaccine readiness trial. The results are important to form a benchmark for the study of vaccination. The results show that after approximately 17 months from seroconversion, oscillations in viremia flattened to a log10 based median set point of 4:08, appearing no different from reported studies in subtype B HIV-1 infected male cohorts. Together with these main outcomes, an analysis of confidence intervals for set point, days to set point and the individual parameters is presented. When estimates for the HIVNET 28 cohort are combined, the data allows a meaningful first estimate of parameters of the three-dimensional HIV/AIDS model for patients from southern Africa. The theoretical basis is used to develop an application that allows medical practitioners to estimate the three-dimensional model parameters for HIV/AIDS patients. The program demands little background knowledge from the user, but for practitioners with experience in mathematical modeling, there is ample opportunity to fine-tune the procedures for special needs. Electrical, Electronic and Computer Engineering Unrestricted 2013-09-06T21:52:01Z 2005-06-13 2013-09-06T21:52:01Z 2004-10-09 2006-06-13 2005-06-13 Dissertation Filter, R 2004, Dynamic HIV/AIDS parameter estimation with Applications, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/25492 > http://hdl.handle.net/2263/25492 http://upetd.up.ac.za/thesis/available/etd-06132005-140606/ © 2004, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle Dynamic parameter estimation
Optimization and medical systems
Parameter variation
Viral set point estimation
Dynamic systems
Hiv/aids model parameters
Bioengineering
UCTD
Dynamic HIV/AIDS parameter estimation with Applications
title Dynamic HIV/AIDS parameter estimation with Applications
title_full Dynamic HIV/AIDS parameter estimation with Applications
title_fullStr Dynamic HIV/AIDS parameter estimation with Applications
title_full_unstemmed Dynamic HIV/AIDS parameter estimation with Applications
title_short Dynamic HIV/AIDS parameter estimation with Applications
title_sort dynamic hiv aids parameter estimation with applications
topic Dynamic parameter estimation
Optimization and medical systems
Parameter variation
Viral set point estimation
Dynamic systems
Hiv/aids model parameters
Bioengineering
UCTD
url http://hdl.handle.net/2263/25492
http://upetd.up.ac.za/thesis/available/etd-06132005-140606/