Developing Alternative Delivery Systems for Methacholine Challenge Tests
Bibliographic record
Abstract
BACKGROUND: The two American Thoracic Society recommended aerosol delivery devices for methacholine challenge testing are both obsolete and often very difficult to acquire, leading to the test being done with a number of nonstandardized nebulizers. Of the two recommended devices, one is the English Wright nebulizer used in the 2-min tidal breathing method, and the other is the DeVilbiss 646 nebulizer used in the five-breath dosimeter method. The purpose of this study was to evaluate the in vitro performance of potential alternative devices that would be economically viable and would minimize environmental contamination. One device was the disposable breath-actuated AeroEclipse(®) II BAN as a potential delivery system for the 2-min tidal breathing, and the second was the automated system by VIASYS as an alternative to either the 2-min tidal breathing or the five-breath dosimeter method. METHODS: A breath simulator mimicked an adult or small child breathing pattern, and a slow inhalation for the five-breath method was generated by a spirometry calibration syringe. Methacholine (Provocholine™) was eluted from filters at the "mouth" and assayed by high-pressure liquid chromatography. RESULTS: In 12 sec, the AeroEclipse II BAN would be expected to have a pulmonary deposition equivalent to the 2-min tidal breathing with the English Wright, whereas the VIASYS system would take approximately 40 sec for the equivalent delivery. The per-breath delivery of the VIASYS and the DeVilbiss 646 was approximately the same, whereas one breath from the AeroEclipse II BAN was the equivalent of five from the DeVilbiss 646. CONCLUSIONS: These data will allow for planning in vivo studies to develop methacholine challenge protocols using modern aerosol delivery systems.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| 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".