title: Respiratory inductive plethysmography: a comparative study between isovolume maneuver calibration and qualitative diagnostic calibration in healthy volunteers assessed in different positions.
abstract: OBJECTIVE
  To compare two methods of respiratory inductive plethysmography (RIP) calibration in three different positions.
  
  
  METHODS
  We evaluated 28 healthy subjects (18 women and 10 men), with a mean age of 25.4 ± 3.9 years. For all of the subjects, isovolume maneuver calibration (ISOCAL) and qualitative diagnostic calibration (QDC) were used in the orthostatic, sitting, and supine positions. In order to evaluate the concordance between the two calibration methods, we used ANOVA and Bland-Altman plots.
  
  
  RESULTS
  The values of the constant of proportionality (K) were significantly different between ISOCAL and QDC in the three positions evaluated: 1.6 ± 0.5 vs. 2.0 ± 1.2, in the supine position, 2.5 ± 0.8 vs. 0.6 ± 0.3 in the sitting position, and 2.0 ± 0.8 vs. 0.6 ± 0.3 in the orthostatic position (p < 0.05 for all).
  
  
  CONCLUSIONS
  Our results suggest that QDC is an inaccurate method for the calibration of RIP. The K values obtained with ISOCAL reveal that RIP should be calibrated for each position evaluated.
authors.affiliation: Department of Physical Therapy and Biomedical Engineering Laboratory, University of São Paulo, Avenida Dr. Arnaldo 455, São Paulo, Brazil.
authors.forename: Renata Cléia Claudino
authors.initials: RC
authors.lastname: Barbosa
authors.forename: Celso Ricardo Fernandes de
authors.initials: CR
authors.lastname: Carvalho
authors.forename: Henrique Takachi
authors.initials: HT
authors.lastname: Moriya
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002138:Calibration; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010991:Plethysmography / Q000379:methods*; D011187:Posture / Q000502:physiology; D012119:Respiration; D012129:Respiratory Function Tests / Q000379:methods*; D013990:Tidal Volume; D055815:Young Adult