title: Computerized Dead-Space Volume Measurement of Face Masks Applied to Simulated Faces.
abstract: BACKGROUND
  The dead-space volume (VD) of face masks for metered-dose inhaler treatments is particularly important in infants and young children with asthma, who have relatively low tidal volumes. Data about VD have been traditionally obtained from water displacement measurements, in which masks are held against a flat surface. Because, in real life, masks are placed against the face, VD is likely to differ considerably between masks depending upon their contour and fit. The aim of this study was to develop an accurate and reliable way to measure VD electronically and to apply this technique by comparing the electronic VD of commonly available face masks.
  
  
  METHODS
  Average digital faces were obtained from 3-dimensional images of 270 infants and children. Commonly used face masks (small and medium) from various manufacturers (Monaghan Medical, Pari Respiratory Equipment, Philips Respironics, and InspiRx) were scanned and digitized by means of computed tomography. Each mask was electronically applied to its respective digital face, and the VD enclosed (mL) was computerized and precisely measured.
  
  
  RESULTS
  VD varied between 22.6 mL (SootherMask, InspiRx) and 43.1 mL (Vortex, Pari) for small masks and between 41.7 mL (SootherMask) and 71.5 mL (AeroChamber, Monaghan Medical) for medium masks. These values were significantly lower and less variable than measurements obtained by water displacement.
  
  
  CONCLUSIONS
  Computerized techniques provide an innovative and relatively simple way of accurately measuring the VD of face masks applied to digital faces. As determined by computerized measurement using average-size virtual faces, the InspiRx masks had a significantly smaller VD for both small and medium masks compared with the other masks. This is of considerable importance with respect to aerosol dose and delivery time, particularly in young children. (ClinicalTrials.gov registration NCT01274299.).
authors.affiliation: Ziv Medical Center, Faculty of Medicine, Bar-Ilan University, Safed, Israel. amirav@012.net.il.
authors.forename: Israel
authors.initials: I
authors.lastname: Amirav
authors.affiliation: Ziv Medical Center, Faculty of Medicine, Bar-Ilan University, Safed, Israel.
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Luder
authors.affiliation: Technosaf, Karkur, Israel.
authors.forename: Asaf
authors.initials: A
authors.lastname: Halamish
authors.affiliation: Ziv Medical Center, Faculty of Medicine, Bar-Ilan University, Safed, Israel.
authors.forename: Chatib
authors.initials: C
authors.lastname: Marzuk
authors.affiliation: Ziv Medical Center, Faculty of Medicine, Bar-Ilan University, Safed, Israel.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Daitzchman
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: D000280:Administration, Inhalation; D000336:Aerosols; D001993:Bronchodilator Agents / Q000008:administration & dosage; D002675:Child, Preschool; D003198:Computer Simulation; D004867:Equipment Design; D005145:Face; D006801:Humans; D021621:Imaging, Three-Dimensional; D007223:Infant; D007231:Infant, Newborn; D008397:Masks; D036501:Metered Dose Inhalers / Q000706:statistics & numerical data*; D012126:Respiratory Dead Space; D012138:Respiratory Therapy / Q000295:instrumentation / Q000706:statistics & numerical data*; D013990:Tidal Volume
chemical_list: D000336:Aerosols; D001993:Bronchodilator Agents
keywords: aerosol; dead space; infants; masks