A Modeling Study on Inspired CO2 Rebreathing Device for Sleep Apnea Treatment by Means of CFD Analysis and Experiment
| Autor: | Ashley Mulchrone, Mehdi Shokoueinejad, Chris Fernandez, Arman Pazouki, John G. Webster, Jake Levin, Jerome A. Dempsey, Fa Wang, Samuel Rusk, Icaro dos Santos |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
business.industry Dead space Biomedical Engineering Apnea Sleep apnea General Medicine 030204 cardiovascular system & hematology Computational fluid dynamics medicine.disease 03 medical and health sciences 0302 clinical medicine 030228 respiratory system Volume (thermodynamics) Control theory Approximation error medicine Breathing Transient (oscillation) medicine.symptom business Simulation |
| Zdroj: | Journal of Medical and Biological Engineering. 37:288-297 |
| ISSN: | 2199-4757 1609-0985 |
| Popis: | We present the device design, simulation, and measurement results of a therapy device that potentially prevents sleep apnea by slightly increasing inspired CO2 through added dead space (DS). The rationale for treatment of sleep apnea with CO2 manipulation is based on two recently reported premises: (i) preventing transient reductions in PaCO2 will prevent the patient from reaching their apneic threshold, thereby preventing “central” apnea and instabilities in respiratory motor output; and (ii) raising PaCO2 and end-tidal CO2, even by a minimal amount, provides a strong recruitment of upper airway dilator muscles, thereby preventing airway obstruction. We have also provided the simulation results, obtained from solving the Navier–Stokes (NS) equations within the device volume. Therein, the NS equations are coupled with a convection–diffusion equation that represents the transport of CO2 in the device, thus enabling the transient simulation of CO2 propagation. Using this procedure, a prototype of variable volume dead space reservoir device was designed. Volumetric factors influencing carbon dioxide increases in the added reservoir (open-ended DS) were investigated. The maximum/minimum amount of CO2 concentration were obtained for the maximum/minimum device volume; 3.4 and 2.4 mol/m3 for the DS volumes of 1.2 and 0.5 × 10−3 m3, respectively. In all case studies, the CO2 buildup reached a plateau after approximately 20 breathing cycles. The experimental measurement results are in agreement with the simulation and numerical results obtained using the proposed simplified modeling technique, with a maximum relative error of 3.5%. |
| Databáze: | OpenAIRE |
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