wifi-densepose/examples/research-sota/07-negative-results
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docs(examples/research-sota): add main + 9 sub-folder READMEs (follow-up to #744) (#745)
PR #744 moved the files into 9 thematic folders via git mv but missed
the READMEs due to a working-directory issue with git add. This PR
adds the actual READMEs:

- examples/research-sota/README.md (main overview)
- examples/research-sota/01-physics-floor/README.md
- examples/research-sota/02-placement/README.md
- examples/research-sota/03-spatial-intelligence/README.md
- examples/research-sota/04-rssi/README.md
- examples/research-sota/05-cross-room-reid/README.md
- examples/research-sota/06-structure-detection/README.md
- examples/research-sota/07-negative-results/README.md
- examples/research-sota/08-verticals/README.md
- examples/research-sota/09-quantum-fusion/README.md

Each sub-README documents:
- Scripts + headlines table
- Why this folder bounds/composes with others
- Sample output / honest scope
- Cross-references to related loop notes + ADRs

Main README covers:
- Folder map with thread numbers
- Cross-folder dependency graph
- 8-entry headline findings table
- Reading order for newcomers (4 scripts in suggested order)
- Honest scope (synthetic-physics caveats)
2026-05-22 07:54:19 -04:00
..
README.md docs(examples/research-sota): add main + 9 sub-folder READMEs (follow-up to #744) (#745) 2026-05-22 07:54:19 -04:00
r13_bp_physics_floor.py chore: organise examples/research-sota/ into 9 thematic folders with READMEs (#744) 2026-05-22 07:52:57 -04:00
r13_bp_results.json chore: organise examples/research-sota/ into 9 thematic folders with READMEs (#744) 2026-05-22 07:52:57 -04:00

README.md

07 — Negative results (R13 contactless BP)

Productive failure: empirical / physics-based scrutiny of widely-claimed but un-validated CSI capabilities.

Scripts

Script Thread Verdict
r13_bp_physics_floor.py R13 Don't ship contactless BP from CSI as a primary RuView feature. Four physics floors make it provably worse than a $20 arm cuff.

The four floors (R13)

Floor Need Have Gap
PTT temporal resolution 0.5 ms (for 1 mmHg) 10 ms typical, 1 ms max ESP32 typical ESP32 deployment cannot do <20 mmHg
Spatial separation of two body sites 55 cm 40 cm Fresnel envelope at 5 m sites NOT resolvable by single link
Pulse-contour SNR +25 dB +20 dB after bandpass 5 dB short (matches R6.1's 4.7 dB penalty)
Vs $20 arm cuff baseline ±2 mmHg best published ±10 mmHg 5× worse + needs per-subject calibration

Why R13 is sensor-bound, not physics-bound-period

R20 (tick 37) + doc 17 + ADR-114 establish that the 5 dB shortfall is the multi-scatterer penalty (R6.1). It's sensor-bound: a different sensor (NV-diamond magnetometer at bedside) recovers what CSI cannot.

Sensor Can detect HRV contour? Can detect BP?
CSI alone (R13 NEGATIVE) 5 dB short same physics
NV-diamond at 1 m bedside (ADR-114) SDNN 119 ms via mm-PWV
Arm cuff (gold standard) n/a ±2 mmHg

R13's value in the loop

Categorising R13 as a permanent physics-floor negative initially saved engineering effort. Then R20 + doc 17 + ADR-114 recategorised it as sensor-bound, recoverable. This is the research-loop pattern at its best: explicit failure modes that survive scrutiny but get reclassified when new tools arrive.

R20.1 (quantum-fusion demo) is the concrete demonstration that R13's recovery works.

Three niche scenarios where BP-from-CSI might close

  1. Single-subject trend monitoring (relative not absolute)
  2. Bed-instrumented controlled-still subject (25+ dB SNR achievable)
  3. Multistatic PWV with 6+ anchors + per-installation calibration

The general "BP from a $9 ESP32 in the corner" claim does not close.

See also

  • Research notes: docs/research/sota-2026-05-22/R13-contactless-bp-negative.md
  • Recovery path: docs/research/sota-2026-05-22/R20-*.md, doc 17, ADR-114
  • The other 2 negative result categories: R12 (missing-tool, revisitable) in 06-structure-detection/, R3.1 (architecture-error) in 05-cross-room-reid/