Evaluation of a Sonomicrometry System for the Measurement of Joint Kinematics
Bibliographic record
Abstract
The measurement of joint kinematics in vivo is an important aspect of the development of new treatment methods for orthopaedic injuries.Existing methods for the measurement of knee joint kinematics are limited by their data collection speeds, expense, and invasiveness.A proposed method uses sonomicrometry crystals mounted on blocks in an arrangement that would establish tibial and femoral coordinate systems.The objectives of this thesis were to: 1) determine the effect of different crystal arrangements and mounting block designs on the measurement of absolute distances using sonomicrometry and 2) determine the effect of mounting block size on the measurement of rotations and translations using sonomicrometry.Sonomicrometry crystals (Sonometrics Corp., London, Ontario) were attached to an electromechanical testing machine and used to measure known distances.The experiment was repeated using different crystal mounting block size, geometry, and composition; as well as with different means of affixing the crystals to the block and different numbers of crystals.These changes will be necessary for the mounting of the crystals in the joint for kinematics measurements.Regression lines were fit to plots of measured versus known distances.In the simplest case, that of two crystals in simple rectangular acrylic blocks, the mean slopes were: 1.01±0.00,1.01±0.00,and 1.01±0.00(mean ± SEM) and the intercepts were: 0.26±0.02,0.52±0.02,and -0.35±0.05.Under the various test conditions (mounting block geometry, size and composition; crystal affixation method; and number of active crystals), the maximum change in slope was 0.03 and the maximum change in intercept was 2.08 mm compared to the simplest case.The changes in intercept were attributed to differences between individual crystals and their sensitivity settings.These sharing his ideas and always being available to answer my endless barrage of questions.Also thanks to Dr. David Butler for providing enthusiasm and leading thoughtful discussion of the physics involved in my research.Others have contributed in their own ways and made the biomedical engineering department a pleasant place to work.Fellow student Nisha Sipes introduced me to sonomicrometry and continued to pitch in and help me with questions even after leaving the department to pursue her doctorate in cell biology.Dr. Shawn Hunter provided technical support with the Test Resources system and interesting music to listen to.Denis Bailey has also worked with the sonomicrometry system, spent substantial time discussing the problems we have faced, and encouraged me in my attempts at long-distance running.I would also like to extend a special thanks to
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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 | 0.008 | 0.014 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".