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Effect of Face Mask Leaks on Inhaled Corticosteroid Delivery to Infants

  • Author / Creator
    Carrigy, Nicholas B.
  • Infant face and throat replicas are used in research laboratories to compare the effectiveness of different valved holding chamber and face mask designs. The use of soft face models is thought to provide a better representation of mask dead volume and face mask seal than hard face models. However, a comparison of mask dead volume, face mask seal, and lung dose for soft versus hard face models is lacking. This study compares mask dead volume, face mask seal, and lung dose for hard ABS, soft silicone, and very soft polyurethane facial materials at two clinically relevant applied forces: 1.5 lb and 3.5 lb. Mask dead volume is quantified using water displacement. Face mask seal is quantified using flow rate measurement. The lung dose of beclomethasone dipropionate delivered via a Qvar® pressurized metered dose inhaler with AeroChamber Plus Flow-Vu™® Valved Holding Chamber and Small Mask, defined as that which passes through the nasal airways of an idealized infant model, is quantified using a bias tidal flow system with a filter. A mathematical model is used to predict lung dose based on experimental results of mask dead volume and flow rate through the valved holding chamber. This study shows that a greater lung dose is obtained using soft face models as compared to hard face models, with a greater difference at 1.5 lb than 3.5 lb. Face mask leakage led to decreased dose consistency and therefore a sealant should be applied when measuring lung dose with a hard ABS or soft silicone face model at 1.5 lb of applied force or less. Parametric analysis with the mathematical model showed that differences in face mask seal between face models were more predictive of lung dose than differences in mask dead volume.

  • Subjects / Keywords
  • Graduation date
    2014-11
  • Type of Item
    Thesis
  • Degree
    Master of Science
  • DOI
    https://doi.org/10.7939/R37082
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
    English
  • Institution
    University of Alberta
  • Degree level
    Master's
  • Department
    • Department of Mechanical Engineering
  • Supervisor / co-supervisor and their department(s)
    • Finlay, Warren H. (Mechanical Engineering)
  • Examining committee members and their departments
    • Noga, Michelle (Radiology and Diagnostic Imaging)
    • Finlay, Warren H. (Mechanical Engineering)
    • Martin, Andrew (Mechanical Engineering)