Simulating the cardinal movements of childbirth using finite element analysis on the graphics processing unit

Gerikhanov, Zelimkhan (2017) Simulating the cardinal movements of childbirth using finite element analysis on the graphics processing unit. Doctoral thesis, University of East Anglia.

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Abstract

Many problems can occur during childbirth which may lead to instant or future
morbidity and even mortality. Therefore the computer-based simulation of the
mechanisms and biomechanics of human childbirth is becoming an increasingly
important area of study, to avoid potential trauma to the baby and the mother
throughout, and immediately following, the childbirth process. Computer-based
numerical methods, such as the Finite Element Method, have become more
widespread to simulate biological phenomena over the last two decades or so.
One of the important aspects of such methods is them being able to accurately
model the underlying physics and biomechanics of biological processes. In the
case of the childbirth process, an important role is played by the fetal head and
its motion as it is being born. The most important manifestations of the head’s
motion are described as the cardinal movements. Being able to model the cardinal
movements in a computer-based model of the human childbirth process is compulsory as they occur in almost every normal delivery. Many existing simulations
use reverse-engineered approaches to model the cardinal movements by imposing
pre-defined trajectories that approximate a real childbirth. These approaches lack
physical accuracy and are unable to extend the simulation to unseen scenarios
where for example the childbirth process does not develop normally. To create
a simulation software capable of simulating realistic, including unseen, scenarios,
and which does not make any pre-simulation assumptions about the cardinal
movements, a physical and forward-engineered approach in which the motions of
the head are determined by the underlying physics, is required.
This thesis presents a simulation system where the physical behaviour of the
fetal head is modelled during the second stage of childbirth. Accurate models
of the fetal head and trunk, the maternal uterine cervix, bony pelvis and pelvic
floor muscles, were created. Some of these are considered to be rigid bodies in
the simulation (fetal head, trunk and maternal bony pelvis), whereas others are
considered to be deformable (maternal uterine cervix and pelvic floor muscles.
The Finite Element Method (FEM) is used to model the deformable tissues by
implementing the Total Lagrangian Explicit Dynamics (TLED) approach on the
GPU. The combined TLED/contact mechanics method was first tested on simple hyperelastic objects. Following successful validation, the interaction between the
fetal head and the deformable tissues was evaluated using a projection based
contact method in conjunction with TLED.
Several experiments had to be done to find the required set of factors contributing
to the occurrence of the cardinal movements. These steps are reported
in the thesis as well as the results of the final experiments which do exhibit the
key cardinal movements of a normal childbirth process, marking the successful,
and key, contribution of this thesis.
The GPU based acceleration allows running the simulation in near real-time,
which makes it possible to create interactive simulations for training purposes
of trainee obstetricians and midwives. The simulation system presented in this
work is also the first step towards a fully patient specific system that would allow
clinicians to diagnose and/or predict adverse scenarios of childbirth based on the
MRI scans of real pregnancies prior to labour.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Science > School of Computing Sciences
Depositing User: Katie Miller
Date Deposited: 11 Jul 2017 15:23
Last Modified: 11 Jul 2017 15:23
URI: https://ueaeprints.uea.ac.uk/id/eprint/64077
DOI:

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