Diaphragmatic Activity and Ventilation in Preterm Infants
Bibliographic record
Abstract
To determine the effects of inhaled CO<sub>2</sub> and abdominal loading on diaphragmatic electromyography (EMG<sub>di</sub>) and ventilation during sleep, we studied 10 preterm infants (birth weight 1,840 ± 50 g; gestational age 32 ± 0.6 weeks and postnatal age 10.4 ± 1.4 days). We measured surface and esophageal diaphragmatic activity. Ventilation was measured using a nasal flowmeter and a flow-through system. Diaphragmatic activity was analyzed for the duration of total phasic and expiratory activities, the expiratory to total phasic activity ratio and the presence of tonic activity (defined by the presence of electrical activity of the diaphragm at the end of expiration). With 3% CO<sub>2</sub> in quiet and REM sleep, the intensity of EMG<sub>di</sub> increased, but the duration of total phasic activity, the expiratory to total phasic activity ratio and tonic activity did not change. During quiet sleep with 3% CO<sub>2</sub>, ventilation increased (0.392 ± 0.028 to 0.616 ± 0.058 1/ min; p = 0.001) due to an increase in tidal volume and frequency. Similar changes occurred in REM sleep. Abdominal loading with sandbags increased the duration of total phasic activity (0.68–0.78 s; p = 0.03), expiratory phasic activity (0.21–0.32 s; p = 0.01), the expiratory to total phasic activity ratio (0.28–0.39; p = 0.03) and diaphragmatic tonic activity (20–60%; p = 0.04) as measured with surface electrodes in REM sleep. It also increased the expiratory to total phasic activity ratio and tonic activity, as measured with surface electrodes in quiet sleep. Abdominal loading did not alter ventilation or the structure of the average breath in either sleep state. These findings indicate that: (1) in healthy preterm infants, inhaled CO<sub>2</sub> alters EMG<sub>di</sub> and the structure of the average breath in a similar manner: the activity increases but timing and tonus are not changed, and (2) abdominal loading alters the structure of diaphragmatic activity as recorded by surface and esophageal electrodes with a significant increase in expiratory activity and tonus, but it does not alter the structure of the average breath.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".