title: More Realistic Face Model Surface Improves Relevance of Pediatric In-Vitro Aerosol Studies.
abstract: BACKGROUND
  Various hard face models are commonly used to evaluate the efficiency of aerosol face masks. Softer more realistic "face" surface materials, like skin, deform upon mask application and should provide more relevant in-vitro tests. Studies that simultaneously take into consideration many of the factors characteristic of the in vivo face are lacking. These include airways, various application forces, comparison of various devices, comparison with a hard-surface model and use of a more representative model face based on large numbers of actual faces.
  
  
  OBJECTIVE
  To compare mask to "face" seal and aerosol delivery of two pediatric masks using a soft vs. a hard, appropriately representative, pediatric face model under various applied forces.
  
  
  METHODS
  Two identical face models and upper airways replicas were constructed, the only difference being the suppleness and compressibility of the surface layer of the "face." Integrity of the seal and aerosol delivery of two different masks [AeroChamber (AC) and SootherMask (SM)] were compared using a breath simulator, filter collection and realistic applied forces.
  
  
  RESULTS
  The soft "face" significantly increased the delivery efficiency and the sealing characteristics of both masks. Aerosol delivery with the soft "face" was significantly greater for the SM compared to the AC (p< 0.01). No statistically significant difference between the two masks was observed with the hard "face."
  
  
  CONCLUSIONS
  The material and pliability of the model "face" surface has a significant influence on both the seal and delivery efficiency of face masks. This finding should be taken into account during in-vitro aerosol studies.
authors.affiliation: Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada; Ziv Medical Center, Safed, Israel.
authors.forename: Israel
authors.initials: I
authors.lastname: Amirav
authors.affiliation: Ziv Medical Center, Safed, Israel.
authors.forename: Asaf
authors.initials: A
authors.lastname: Halamish
authors.affiliation: Nuclear Medicine Department, Ziv Medical Center, Safed, Israel.
authors.forename: Miguel
authors.initials: M
authors.lastname: Gorenberg
authors.affiliation: Nuclear Medicine Department, Ziv Medical Center, Safed, Israel.
authors.forename: Hamza
authors.initials: H
authors.lastname: Omar
authors.affiliation: Firestone Institute for Respiratory Health, St. Joseph's Hospital, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Newhouse
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004867:Equipment Design; D005145:Face / Q000033:anatomy & histology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008397:Masks; D008953:Models, Anatomic