Assessing asymmetry using reflection and rotoinversion in biomedical engineering applications
Bibliographic record
Abstract
Symmetry is a trait that has been extensively reviewed, especially clinically, as an indication of ideal geometry and health. Many geometric symmetry assessment techniques rely on two-dimensional measurements that do not account for the three-dimensional nature of the object. In this article, two methods, reflection and a process termed rotoinversion, a combination of reflection and rotation, are presented as potential methods to assess an object's deviation from symmetry. With reflection, the geometric models are reflected about a calculated best plane of symmetry. With rotoinversion, the models are reflected about an arbitrary plane and then rigidly translated and rotated to best align the translated and original models. The methods give the same results for bilaterally symmetric objects, but different results for bilaterally and rotationally symmetric objects. The two methods are applied to assess asymmetry in adolescent idiopathic scoliosis torso geometric models, producing similar results. There was an angle of 0.408° between the normal to the plane of reflection from the reflection process and the normal from the rotoinversion process and average rotation of 0.067° from rotoinversion. The most appropriate method depends on the purpose of the symmetry assessment and must be determined on a case-by-case basis.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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".