Respiratory oscillometry in infants: methodological aspects
Bibliographic record
Abstract
Background: Oscillometry in infant lung function is of emerging potential but is challenged by special conditions (sleep, position, nasal breathing and high mechanical impedance) not encountered in older age groups. Aims: To investigate the effects of face mask positioning and head support on respiratory impedance (Zrs) in infants. Methods: Sedated infants (n=21) who were born preterm (25-37 wk gestational age) were evaluated longitudinally as outpatients at corrected-ages of 5-6 (visit 1; V1) and 12 months (V2). A device in development (N-100; Thorasys Inc., Montreal, CA) was employed to measure Zrs in the 7-41-Hz range. The head/mask support was accomplished with 1 hand (1H) or 2 hands (2H); >3 regular segments of 7 s were collected in each condition. The Zrs spectra were processed to correct (corr) for the face mask shunt. Mean resistance (R), compliance (C), and resonance frequency (fres) were estimated via model fitting. Results: Uncorrected Zrs failed to exhibit fres in 12 (V1) and 1 (V2) subjects and resulted in unexpectedly low C values. V1 and V2 results reflected growth (Table 1). There was no significant difference in any measure with 1H and 2H support (signed rank test). erj;64/suppl_68/PA1462/TB1 T1 TB1 V1 V1corr V2 V2corr R (cmH2O.s/L) 31.9 [27.2;36.3] 33.4 [28.9;39.2]* 25.7 [19.8;29.8]# † 23.2 [19.7;27.5]* †† C (mL/cmH2O) 1.08 [0.86;1.32] 1.56 [1.13;1.90]** 1.62 [1.23;2.10]# † 1.89 [1.56;2.84]** † fres (Hz) 53.1 [39.3;61.0] 17.6 [16.1;23.6]* 28.6 [23.1;37.8]# 16.4 [13.4;18.0]** † Table 1. Median [25%;75%] values of Zrs measures. p corr vs uncorr: <0.05*, <0.001**; V2 vs V1: <0.05†, <0.001†† Conclusion: Correction for the face mask shunt impedance provided more realistic Zrs spectra and derived measures, especially at high Zrs values.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.018 | 0.024 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".