Computer Calculations of Exercise Dead Space: The Role of Laminar Flow, and Development of a Clinical Prediction Formula
Bibliographic record
Abstract
The behaviour of the anatomical dead space cannot be described by passage of a ‘square’ wave front through the conducting airways, with subsequent diffusion of alveolar gas back up the bronchial tree. A computer model based on these assumptions leads to overestimation of the dead space during both rest and exercise. It is suggested that these discrepancies arise from laminar (axial) flow in the smaller airways. A simple description of the anatomical dead space is given by the equation VD = Vf+ (Ve-200)e-kt where VD is the volume of the anatomical dead space, Vf is the volume of the conducting airway to the fifteenth order bronchioles, Ve is the volume from the sixteenth order bronchioles to the second or third order alveolar ducts, 200 is an empirical correction for laminar gas flow, k is a diffusion constant (1.0 for nitrogen, 0.8 for carbon dioxide) and t is the half length of the respiratory cycle, measured in seconds.
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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 | 0.002 | 0.012 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 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".