2026-05-19T14:00:41Zhttps://keep.lib.asu.edu/oai/request

oai:keep.lib.asu.edu:node-2013042025-05-06T22:43:47Zoai_pmh:repo_items

201304 https://hdl.handle.net/2286/R.2.N.201304 http://rightsstatements.org/vocab/InC/1.0/ All Rights Reserved 2025 2027-05-01T17:46:23 84 pages Doctoral Dissertation Academic theses en Nguyen, Ngan Anh Forzani, Erica Raupp, Gregory Lind, Mary Laura Chen, Fang Mora, Sabrina Arizona State University Partial requirement for: Ph.D., Arizona State University, 2025 Field of study: Chemical Engineering This study explores the relationship between fat oxidation and breath acetone by addressing three key objectives. First, a novel fat oxidation model incorporating ketogenesis (Ketogenesis-Integrated Model, KIM) was developed to represent a crucial metabolic process that influences weight loss and energy balance. The model, derived from fundamental mass balance and biochemical process principles, provides a comprehensive representation of fat metabolism. Second, the model was validated through a pilot study involving 16 healthy subjects undergoing controlled ketogenic interventions, including exercise, fasting, and ketogenic meal while controlling the baseline at four different conditions: 1- normal diet with energy balance, 2- ketogenic diet with energy balance, 3- normal diet with negative energy balance, and 4- ketogenic diet with negative energy balance. Ketogenesis contributions to fat oxidation rates in the new model were evaluated with a previously established and widely used model. The comparisons demonstrated that the new model exhibits better predictive fat oxidation rate during ketogenesis. Correlation between calculated fat oxidation rate from the developed model and measurable breath acetone was also obtained. A strong correlation (R² = 0.96) between model-predicted fat oxidation and breath acetone levels confirmed acetone as a reliable non-invasive biomarker for fat oxidation. In the third objective, a colorimetric acetone sensor was developed to enable the practical quantification of fat oxidation. This sensor was designed for integration into a commercially available portable breath analyzer, allowing for non-invasive and real-time metabolic monitoring. The system employs green LEDs and photodiodes to detect colorimetric changes that correspond to acetone concentration. The measured breath acetone concentration is then used to estimate the fat oxidation rate, based on the validated correlation established in the second objective between fat oxidation and breath acetone levels. Chemical Engineering breath acetone sensor Colorimetric Detection fat oxidation model ketogenesis ketone biomarkers liquid-core microspheres A Novel Fat Oxidation Model Integrating Ketogenesis and Breath Acetone Sensor for Non-Invasive Metabolic Assessment