Oxygen flowmeters: accuracy and precision in adult care
Bibliographic record
Abstract
Oxygen flowmeter is an equipment used to control oxygen flow delivery in patients undergoing oxygen therapy. Objective: To evaluate accuracy and precision of oxygen flowmeters used in adult care. Methods:In vitro experimental study that evaluated 160 oxygen flowmeters (Flow range 0 to 15L/min), without previous use, manufactured in eight different countries (Australia, Brazil, Canada, China, England, France, Italy and United States of América). Flowmeters were tested at four flow rates, 1, 3, 5 and 10 L/min, with three repeated measurements in each flow. During the tests, the flowmeters were connected to the gas system through a reduction valve and a flow analyzer (FlowAnalyzer™ PF-302; Imtmedical Ag. Buchs Switzerland). The float (metal sphere) of the flowmeter was set to zero and then was kept at the corresponding mark of the flow to be tested. Was considered accurate flowmeter that maintained the three measurements within a ±10% variation, and precise, flowmeter that present no difference greater than 10% among repeated measurements (1st vs 2nd, 1st vs 3rd, 2nd vs 3rd). Results: The accuracy percentage in the low-flows (1 and 3L/min) was significantly lower than in the high-flows (5 and 10L/min). Flowmeters samples showed high precision in all tested flows (65 to 100%), specially at flows rate 5 and 10L/min (100%). None of the set of the flowmeters met the ideal expectation of 100% combined of accuracy and precision flows in all four tested. Conclusion: None of the eight different countries samples presented accurate and precision for all four tested flows. The flowmeters precision percentage was high despite their low accuracy.
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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 | 0.026 | 0.032 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
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".