New digital quadrature demodulator for real-time hand-held ultrasound medical imaging device
Bibliographic record
Abstract
A real-time, low-power digital quadrature demodulator is proposed to process ultrasound radio frequency signals in both pulse and continuous modes. Two finite impulse response filters are combined to build a Hilbert transform and a linear approximation architecture that allows achieving the required square root operations of quadrature demodulator. The complexity and accuracy of proposed demodulator are analyzed and successfully integrated in an FPGA as a low-power building block. Results show the proposed digital back-end demodulator is accurate, which motivates us to integrate in a miniaturized ultrasound receiver. Only 12 MULT18times18 and 1473 slices of the FPGA resources were required to synthesize the quadrature demodulator. Also, real-time images were acquired from a reference phantom demonstrating the feasibility of using the proposed architecture to accomplish real-time digital quadrature demodulation of echoes resulting from ultrasonic signals.
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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) | 0.000 | 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 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 0.002 |
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".