ORCID Identifier(s)

0009-0003-9182-6843

Graduation Semester and Year

Spring 2026

Language

English

Document Type

Thesis

Degree Name

Master of Science in Biomedical Engineering

Department

Bioengineering

First Advisor

Liping Tang

Second Advisor

Shiyao Lin

Third Advisor

Jun Liao

Abstract

Nasal prongs are widely used for continuous positive airway pressure (CPAP) therapy in premature infants, yet 20-60% develop nasal injury. Although nasal masks and binasal prongs deliver comparable respiratory support, each interface produces distinct injury patterns: masks commonly injure the philtrum, while prongs predominantly overload the columella and nasal septum. Injury persists despite routine interface rotation, largely due to prong-size mismatch, the fragility of neonatal skin, prolonged use, and positioning variability. However, the mechanical basis of these injuries remains poorly quantified, and existing models lack anatomical fidelity. To address this gap, a three-dimensional finite element (FE) framework was developed to characterize the mechanical interaction between CPAP prongs and neonatal nasal anatomy. Anatomically accurate head models representing infants aged 2 weeks and 4.5 months were reconstructed from MRI scans. Commercial prongs (sizes 3020-5560) were digitally replicated and inserted into each model. Using Abaqus/Explicit and a hyperelastic silicone surrogate for neonatal soft tissue, simulations quantified von Mises normal stress, shear stress, and contact pressure at a standardized reaction force of approximately 0.005 N. Across all simulations, peak stress consistently localized to the columella, confirming it as the primary site of mechanical overload. In the 2-week infant, maximum normal stress ranged from 0.0557 MPa with the 3020 prongs to 0.1107 MPa with the 5050 prongs. In the 4.5-month infant, the lowest stress occurred with the 4030 prongs (0.08202 MPa), whereas the undersized 3020 prongs produced the highest stress (0.1223 MPa) due to pronounced pinching. This work provides the first anatomically grounded, quantitative assessment of prong-tissue loading in neonates. The framework establishes a foundation for evaluating prong fit, guiding clinical sizing practices, and informing future device design to reduce CPAP-associated nasal injury in premature infants.

Keywords

Neonatal CPAP, nasal prongs, preterm infants, nasal septum injury, finite element analysis, contact mechanics, medical device design, MRI-based anatomical modeling, Abaqus

Disciplines

Applied Mechanics | Biomechanical Engineering | Biomechanics and Biotransport | Biomedical Devices and Instrumentation | Computer-Aided Engineering and Design | Respiratory System | Tissues

License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Download

Available for download on Sunday, December 12, 2027

Share

COinS