Date of Award

Fall 12-2022

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Electrical & Computer Engineering

Program/Concentration

Modeling and Simulation

Committee Director

Yuzhong Shen

Committee Member

Michel Audette

Committee Member

Robert E. Kelly, Jr.

Abstract

Congenital chest wall deformities (CWD) are malformations of the thoracic cage that become more pronounced during early adolescence. Pectus excavatum (PE) is the most common CWD, characterized by an inward depression of the sternum and adjacent costal cartilage. A cross-sectional computed tomography (CT) image is mainly used to calculate the chest thoracic indices. Physicians use the indices to quantify PE deformity, prescribe surgical or non-surgical therapies, and evaluate treatment outcomes. However, the use of CT is increasingly causing physicians to be concerned about the radiation doses administered to young patients. Furthermore, radiographic indices are an unsafe and expensive method of evaluating non-surgical treatments involving gradual chest wall changes. Flexible tape or a dowel-shaped ruler can be used to measure changes on the anterior side of the thorax; however, these methods are subjective, prone to human error, and cannot accurately measure small changes. This study aims to fill this gap by exploring three-dimensional optical imaging techniques to capture patients’ chest surfaces.

The dissertation describes the development and validation of a cost-effective and safe method for objectively evaluating treatment progress in children with chest deformities.

First, a study was conducted to evaluate the performance of low-cost 3D scanning technologies in measuring the severity of CWD. Second, a multitemporal surface mesh registration pipeline was developed for aligning 3D torso scans taken at different clinical appointments. Surface deviations were assessed between closely aligned scans. Optical indices were calculated without exposing patients to ionizing radiation, and changes in chest shape were visualized on a color-coded heat map. Additionally, a statistical model of chest shape built from healthy subjects was proposed to assess progress toward normal chest and aesthetic outcomes.

The system was validated with 3D and CT datasets from a multi-institutional cohort. The findings indicate that optical scans can detect differences on a millimeter scale, and optical indices can be applied to approximate radiographic indices. In addition to improving patient awareness, visual representations of changes during nonsurgical treatment can enhance patient compliance.

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In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

Copyright, 2023, by Nahom Kidane, All Rights Reserved.

DOI

10.25777/c8y0-ma84

ISBN

9798371979759

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