Constrained optimal control of needle deflection for semi-manual steering
Bibliographic record
Abstract
Brachytherapy is a widely used treatment for patients with localized cancer where high doses of radiation are administered to cancerous tissue by implanting radioactive seeds into the prostate using long beveled-tip needles. Accurate seed placement is an important factor that influences the outcome of the treatment. In this paper, we present and study the suitability of a new framework for computer-assisted needle steering during seed implantation in brachytherapy. The framework is based on a hand held brachytherapy needle steering apparatus. As the needle is manually inserted, the device automatically rotates the needle's base axially at appropriate depths inside tissue in order to control the trajectory of the needle tip towards a target. The steering controller is based on the Rapidly Exploring Random Tree algorithm that updates the necessary manoeuvres online. Experimental results performed in phantom and ex-vivo biological tissues show an average absolute targeting error of 0.56 ±0.62 and 0.48 ±0.48 mm, respectively.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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".