A dynamic neonatal heart phantom for ultrafast color Doppler echocardiography evaluation
Bibliographic record
Abstract
New high-frame-rate ultrasound imaging techniques are being developed to image tissue motion and blood flow with high sensitivity and at high temporal resolution. An emerging application for these new techniques is diagnosing inutero and neonatal cardiac disease. We have developed a morphologically and hemodynamically accurate neonatal heart phantom to provide a high-fidelity physical model for laboratory testing of ultrafast color Doppler echocardiography methods. This paper summarizes the design and functionality of the simulator by measuring pressure gradients across the mitral valve at a physiologic heart-rate range and stroke volume and by evaluating valve function using 2D transesophageal echocardiography (TEE) and Doppler images. The phantom achieved normal physiological pressures across the mitral valve ranging from 42 to 87 mmHg in systole and 2.4 to 4.2 mmHg in diastole at heartrates of 100, 125 and 150 beats per minute (bpm), with a realistic neonatal stroke volume of 7 ml. 2D ultrasound images were obtained at 60 bpm.
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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 | 0.001 | 0.002 |
| 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 | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".