Figures
- Fig. 1.—
(–)(‐‐‐)()-()Schematic illustration of the frequency dependence of respiratory impedance of adults in the medium frequency range, in health and disease. Compared to the normal impedance data , in airway obstruction, respiratory resistance is higher a and negatively frequencydependent, whereas respiratory reactance is lower b. Arrow indicates resonant frequency.
- Fig. 2.—
(Schematic arrangement of the forced oscillatory respiratory impedance Zrs,in) measurement. Pap: airway opening pressure; V': airflow.
Tables
- Table 1
(Overview of the average respiratory resistance Rrs) value obtained in healthy adults.
Reference Selection criteria Frequency band Hz Male Female Rrs·· kPasL−1 n Age yrs Rrs·· kPasL−1 n Age yrs 28 /Male Air Force membersapplicants –424 ()0.25 0.06 224 ()26 10 29 ? –824 ∼ 0.26 442 29 30 Patients undergoing rehabilitation and healthy hospital workers 10 ()+0.29 0.08 MF 102 50 31 ? –624 ()0.26 0.06 126 ()33 12 ()0.30 0.06 100 ()29 12 24 “”Healthy subjects referred for lung function testing –1032 ()0.26 0.07 32 ()48 15 ()0.34 0.07 28 ()55 13 32 “”Healthy subjects referred for lung function testing –624 ()0.25 0.05 137 ()53 14 ()0.31 0.07 140 ()58 14 -
(Data are presented as mean sd)
-
M: male
-
F: female
-
n: number of subjects studied
-
- Table 2
(Prediction equations for the average resistance Rrs())(0, average reactance Xrs())(0 and slope of resistance to frequency Rrs())1, and the residual sd( Rsd)
Male Rrs()=−+–+(00.2454.H0.001564.W0.00055.A0.5919 Rsd=)0.0493 Rrs()=–––(10.00842.H0.000047.W0.000018.A0.0095 Rsd=)0.00197 Xrs()=–––(00.1479.H0.000402.W0.00022.A0.1721 Rsd=)0.0306 Female Rrs()=−+–+(00.4300.H0.00165.W0.00070.A0.9312 Rsd=)0.0619 Rrs()=–––(10.01176.H0.000106.W0.000045.A0.00817 Rsd=)0.00256 Xrs()=–––(00.2487.H0.001700.W0.00053.A0.2158 Rsd=)0.0406 -
Rrs()0 and Xrs()··0 in kPasL−1, Rrs()·1 in kPas2·L−1
-
()H: height m
-
()W: weight kg
-
()A: age yrs
-
Reproduced with permission from 32
-
- Table 3
(Overview of the regression equations of respiratory resistance Rrs) as a function of height in healthy children
Reference Frequency band Hz Subjects n Age yrs Rrs·· kPasL−1 Rsd 42 –1535 16 –35 R(–)rs1535=−×+0.00529H1.102 41 4, 9 130 –314 Rrs4=–×2.470.013H 36 –310 121 –416 Rrs4=×1.87104×H–2.12 38 –226 138 –216 Rrs6=×9.210−5×H2–×+0.0341H3.52 0.15 40 2, 4, 12 218 –218 (logRrs4)=–×()4.4132.18log H %10.2 34 –226 255 –212 Rrs6=×0.00017H2–×+0.05407H4.77323 0.175 39 10 377 –318 Rrs10=–×1.3920.00635H 0.066 44 5 247 –36.5 Rrs5=−×+0.009528H2.0643065 45 8, 12, 16 199 –317 (ln Rrs8)=–×()10.9902.370ln H -
()H: height cm
-
Rsd: residual sd
-
- Table 4
()-()Short term within day intraindividual variability of forced oscillation technique FOT indices in adult, healthy subjects and patients
Reference FOT index Subjects studied %CV 48 R rs10 Healthy subjects 11.3 Asthmatics 10.3 49 R rs8 Healthy subjects 8.3 Asthmatics 10.0 50 |Zrs10| Asthmatics 4.9 12 R –rs432 Healthy subjects 4.7 30 R rs10 Healthy subjects 9.8 51 R rs10 Healthy subjects 8.6 COPD patients 8.8 52 R rs6 Patients with airway obstruction 15.2 52 R -rs626 Patients with airway obstruction 12.1 -
Rrs6, Rrs8, Rrs10: Rrs measured at 6, 8 or 10Hz
-
|Zrs10 |: modulus at 10Hz
-
CV: coefficient of variation
-
- Table 5
Abbreviation Description Unit ao Airway opening aw Airway bs Body surface es Oesophageal f Frequency Hz f res Resonant frequency Hz FRC Function residual capacity L G (/Conductance 1R) ·LkPa−1·s−1 Gaw (/Airway conductance 1Raw) ·LkPa−1·s−1 Grs (/Total respiratory conductance 1Rrs) ·LkPa−1·s−1 sGaw (=Specific airway conductance G/)awFRC kPa−1·s−1 in Input L Pulmonary system P Pressure kPa R Real part of Z or resistance ··kPasL−1 rs Respiratory system R aw Airway resistance measured by body plethysmography ··kPasL−1 sRaw (/Specific airway resistance 1sGaw) ·kPas R rs f Total respiratory resistance measured at frequency f ti Tissue tr Transfer V' Airflow ·Ls−1 w Chest wall X Imaginary part of Z or reactance ··kPasL−1 Z Impedance ··kPasL−1
