Time-domain 3D localization of fluorescent inclusions in a thick scattering medium
Bibliographic record
Abstract
We introduce an improved approach in the 3D localization of discrete fluorescent inclusions in a thick scattering medium. Previously our approach provided accurate localization of a single inclusion, showing the potential for direct time-of-flight fluorescence diffuse optical tomography. Here, we localize various combinations of multiple fluorescent inclusions. We resort to time-domain (TD) detection of emitted fluorescence pulses after short pulse laser excitation. Our approach relies on a signal processing technique, dubbed numerical constant fraction discrimination (NCFD), for extracting in a stable manner the arrival time of early photons emitted by one or many fluorescent inclusions from measured time-of-flight (TOF) distributions. Our experimental set-up allows multi-view tomographic optical TD measurements over 360 degrees without contact with the medium. It uses an ultra-short pulse laser and ultra-fast time-correlated single photon counting (TCSPC) detection. Fluorescence time point-spread functions (FTPSFs) are acquired all around the phantom after laser excitation. From measured FTPSFs, the arrival time of a fluorescent wavefront at a detector position is extracted with our NCFD technique. Indocyanine green (ICG; absorption peak = 780nm, emission peak = 830nm) is used for the inclusions. Various experiments were conducted with this set-up in a stepwise fashion. First, single inclusion experiments are presented to provide background information. Second, we present results using two inclusions in a plane. Then, we move on with two inclusions located in different planes. Finally, we show results with a plurality of inclusions (>2) distributed at arbitrary positions in the medium. Using an algorithm we have developed and tested on the acquired data, we successfully achieve to locate the inclusions. Here, results are obtained for discrete inclusions. In a close future, we expect to extend our method to continuous fluorescence distributions.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 |
| 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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| 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".