Effect of Subcutaneous Implantation of Anti-Siphon Devices on CSF Shunt Function
Bibliographic record
Abstract
Anti-siphon devices (ASD) were initially bench tested at flow rates between 10 and 50 cm3/h and with the distal catheter height between 0 and -60 cm. There was a small increase in pressure with increased flow rate in the horizontal position (p less than 0.001). The inflow pressure initially dropped with the distal catheter height at -20 cm; it then rose progressively with distal catheter heights of -40 and -60 cm (p less than 0.001). To determine the effect of ambient pressure the devices were placed in a barometric chamber at pressures between -200 and +200 mm H2O. Positive pressures caused a linear increase in inflow pressure; negative chamber pressure reduced the anti-siphon effect. Eight ASDs were implanted subcutaneously in piglets and tested in situ weekly for 4 weeks. Implantation caused a mean increase in inflow pressure of 93.5 mm H2O 7 days after implantation (p less than 0.001) and which persisted for 4 weeks. Incision of the capsule surrounding the ASD at the end of 4 weeks caused a drop in pressure. The capsule consisted of an outer layer of collagen fibres with an inner layer of histiocytes. Subcutaneous implantation of ASDs causes an increase in the ambient pressure of the device which significantly increases their resistance to flow.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".