Placental haemodynamics: a computational study of maternal blood flow and oxygen transport in the human placenta
In this thesis, we present mathematical models used to describe maternal blood flow and oxygen transport in the at-term human placenta. We take a computational approach using discontinuous Galerkin finite element methods, which allows us to expand upon previous work by considering a complex 2D place...
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| Format: | Thesis (University of Nottingham only) |
| Language: | English English English English English |
| Published: |
2024
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| Online Access: | https://eprints.nottingham.ac.uk/79788/ |
| Summary: | In this thesis, we present mathematical models used to describe maternal blood flow and oxygen transport in the at-term human placenta. We take a computational approach using discontinuous Galerkin finite element methods, which allows us to expand upon previous work by considering a complex 2D placental geometry that respects the main structural features of the placenta.
One third of stillbirths are related to placental dysfunction, and therefore the overarching motivation for this work is to better understand characteristics of diseased placentas. This thesis studies maternal placental flow in three contexts, listed as follows.
Firstly, we study how placental efficiency is affected by changes in structural parameters. We achieve this by generating a large number of flow and oxygen realisations, whereby parameters such as the number and position of arteries and veins in our computational domain are varied; this allows us to infer how changes in placental structure affect placental function.
Taking the work in a second direction, we provide a method for comparing simulated flows with MRI data. We achieve this by advecting particles due to an underlying flow field, and modelling the evolution of each particle's magnetic spin, from which we can compute MRI signals. We compute these signals on simulated flow fields from our model of maternal blood flow, and on simpler manufactured sub-voxel shear flow, rotational flow, and accelerating flow fields; this allows us to infer the relationship between simple sub-voxel flow fields, our model of maternal blood flow, and real placental MRI data.
Thirdly, we introduce a preliminary model of the recently-documented utero-placental pump, where the entire placenta periodically reduces by up to 40% in volume, resulting in periodic ejection of blood from the placenta. We achieve this by prescribing a simple form of boundary motion in order to study the effect this has on flow and oxygen concentration. We show that contractions of this nature do influence the oxygen transport dynamics, and therefore could prove useful in understanding disease in the placenta. |
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