Dissertations and Theses (Open Access)
Date of Award
Spring 5-2026
Degree Name
Doctor of Philosophy in Nursing (PhD)
Advisor(s)
Cathy L. Rozmus, PhD
Second Advisor
Nikhil Padhye, PhD
Third Advisor
Jun Teruya, M.D.
Abstract
Background: Neonates requiring extracorporeal membrane oxygenation (ECMO) are at high risk for thrombotic complications, which contribute substantially to morbidity and mortality. Current circuit surveillance methods rely on intermittent visual inspection and indirect laboratory markers, both of which often detect thrombosis only after clinically significant progression. Optical approaches offer a non-invasive alternative for earlier clot visualization, yet the influence of illumination wavelength on detection performance under realistic ECMO conditions remains incompletely characterized.
Methods: This study evaluated wavelength-dependent clot detection performance in a controlled in-vitro neonatal ECMO circuit model using a portable imaging prototype designed to emulate bedside workflow. Twelve independent ECMO runs were performed using anonymized human whole blood, generating 131 clots and 1,718 wavelength-specific assessments. Four illumination conditions were compared: a broad-spectrum visible-light (flashlight) comparator operationally labeled as 400 nm, 660 nm, 850 nm, and dual-wavelength illumination (660 nm + 850 nm). Primary endpoints included time to first detection, apparent clot size at first detection, and probability of visualization across repeated assessments. Hierarchical mixed-effects models accounted for repeated measures within clots and clustering within runs.
Results: Illumination wavelength significantly influenced all three detection endpoints. Near-infrared illumination at 850 nm produced earlier detection, higher probability of visualization across repeated assessments, and larger apparent clot size at the moment of first visualization. The flashlight consistently demonstrated inferior detection performance. Differences in apparent size were interpreted as wavelength-dependent optical contrast effects rather than accelerated clot growth.
Conclusion: These findings demonstrate that wavelength selection affects the timeliness and reliability of clot visualization in blood-filled ECMO circuits. Near-infrared illumination at 850 nm offers a plausible and empirically supported advantage over conventional flashlight inspection. This work establishes a rigorous preclinical foundation for wavelength-optimized ECMO surveillance and supports further translational evaluation focused on bedside feasibility and patient-centered outcomes.
Recommended Citation
Holmes, Amanda, "In-Vitro Testing of Light Wavelength to Detect Clots in Neonatal Extracorporeal Membrane Oxygenation Circuitry" (2026). Dissertations and Theses (Open Access). 76.
https://digitalcommons.library.tmc.edu/uthson_etd/76
Keywords
In-Vitro Testing, Clots, Neonatal Extracorporeal Membrane Oxygenation Circuitry