Fig 1.
Materials used for MIP assessment by unidirectional expiratory valve method: (1) unidirectional expiratory valve; (2) straight connector; (3) T-tube; (4) face mask; (5) digital vacuum manometer.
Fig 2.
Process of MIPuni assessment.
Table 1.
Anthropometric characteristics and pulmonary function variables.
n: number of subjects; kg: kilograms; m: meters; BMI: body mass index. FVC (% predicted): estimated percentage of predicted forced vital capacity; FEV1 (% predicted): estimated percentage of predicted forced expiratory volume in the first second; FEF 25–75% (% predicted): estimated percentage of predicted mean forced expiratory flow between 25% and 75% of FVC; VC (% predicted): estimated percentage of predicted vital capacity; IC: inspiratory capacity (L: liter); ERV: expiratory reserve volume.
Fig 3.
Bland-Altman plots of the agreement between MIPsta and MIPuni values (absolute values).
MIPsta: Maximal inspiratory pressure evaluated by standard method; MIPuni: Maximal inspiratory pressure evaluated by unidirectional expiratory valve method; X axis: Mean of MIP values obtained by MIPuni and MIPsta for each subject of the study (MIPuni value + MIPsta value /2); Y axis: Difference between MIP values obtained by MIPuni and MIPsta for each subject (MIPuni value–MIPsta value); UL: Upper limit; LL: Lower limit.
Table 2.
MIP evaluated by unidirectional expiratory valve method.
n: number of subjects; cmH20: centimeters of water.
Table 3.
Inter- and intraobserver reproducibility of unidirectional expiratory valve method.
ICC[2,1]: intraclass correlation coefficient; CI 95%: 95% confidence interval, p: level of significance.
Fig 4.
Bland-Altman plots of the inter- and intraobserver agreement between MIPuni values (absolute values).
a) X axis: Mean of MIP values obtained by evaluators A and B for each subject of the study (Value by evaluator A + Value by evaluator B /2); Y axis: Difference between MIP values obtained by evaluators A and B for each subject (Value by evaluator B–Value by evaluator A). b) X axis: Mean of MIP values obtained by evaluator A or B for each subject in Tests 1 and 2 (Value by evaluator A or B in Test 1 + Value by evaluator A or B in Test 2 /2); Y axis: Difference between MIP values obtained by evaluator A or B for each subject in Tests 1 and 2 (Value by evaluator A or B in Test 2—Value by evaluator A or B in Test 1). UL: Upper limit; LL: Lower limit.
Table 4.
MIP measurement repeatability.
ICC[2,1]: intraclass correlation coefficient; CI 95%: 95% confidence interval, p: level of significance.
Fig 5.
Bland-Altman plots of the agreement between MIP values obtained by standard method and by unidirectional expiratory valve method (absolute values).
X axis: Mean between the first and last MIP values obtained by each method for each subject (First value + Last value /2); Y axis: Difference between the last and first MIP value obtained by each method for each subject (Last value–First value); UL: Upper limit; LL: Lower limit.