Mechanical output impedance of the lung determined from cardiogenic oscillations
Bibliographic record
Abstract
The beating heart naturally oscillates the lung because of the close juxtaposition between these organs producing cardiogenic oscillations in flow that can be measured at the mouth when the glottis is open. Correspondingly, if the mouth is occluded, the same phenomenon produces cardiogenic pressure oscillations that can be measured just distal to the site of occlusion. The Fourier-domain ratio of these oscillations in pressure and flow constitutes what we call cardiogenic respiratory impedance (Zc). We calculated Zc between about 1.5 and 10 Hz in relaxed normal subjects at functional residual capacity with open glottis. Zc was insensitive to heart rate changes induced by exercise and had an imaginary part close to zero at all frequencies investigated. Its real part was similar to or smaller than resistance determined by the forced oscillation technique. We speculate that Zc measures the flow resistance of the central and upper airways of the lung. Zc may be useful as a means of obtaining information about lung mechanics without the need for an external source of flow perturbations.
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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 | 0.000 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".