8fb6ef6547
§A2 (correctness): BreathingExtractor weighted fusion was an un-normalized sum.
When `weights` was supplied shorter than n, supplied entries were used raw while
the missing tail defaulted to uniform 1/n -- two scales summed with no
renormalization, silently mis-scaling the breathing signal by a factor of
weights.len(). Extract to fuse_weighted_residuals() and normalize by
Sigma(effective weights), mirroring heartrate::compute_phase_coherence_signal.
Tests: partial_weights_are_renormalized_not_scale_mixed,
partial_weights_fusion_is_weighted_average (both fail on old code).
§A3 (stability): the IIR resonator pole radius r = 1 - bw/2 diverges when the
pole MAGNITUDE |r| >= 1 (i.e. bw >= 4: a very low fs relative to band width) --
NOT merely when r is negative, as the research report stated (a negative r with
|r| < 1 is still stable; the comments/tests are corrected accordingly). On
divergence the filter overflows to +/-inf within ~600 frames, NaN-poisons acf0,
and the extractor stalls permanently. Clamp r to [0, 0.9999] AND finite-guard
the filter output before the history push (defense-in-depth, mirrors ADR-154 §3).
Applied to both heartrate.rs and breathing.rs. Tests:
{heartrate,breathing}::low_sample_rate_filter_stays_finite (fs=0.5, 0.1-0.9 Hz
band, 600-frame unit step -> all-finite; both panic on old code).
These files also carry the §A1 VecDeque window conversion (bit-identical).
Co-Authored-By: claude-flow <ruv@ruv.net>
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|---|---|---|
| .. | ||
| benches | ||
| src | ||
| Cargo.toml | ||
| README.md | ||
README.md
wifi-densepose-vitals
ESP32 CSI-grade vital sign extraction: heart rate and respiratory rate from WiFi Channel State Information (ADR-021).
Overview
wifi-densepose-vitals implements a four-stage pipeline that extracts respiratory rate and heart
rate from multi-subcarrier CSI amplitude and phase data. The crate has zero external dependencies
beyond tracing (and optional serde), uses #[forbid(unsafe_code)], and is designed for
resource-constrained edge deployments alongside ESP32 hardware.
Pipeline Stages
- Preprocessing (
CsiVitalPreprocessor) -- EMA-based static component suppression, producing per-subcarrier residuals that isolate body-induced signal variation. - Breathing extraction (
BreathingExtractor) -- Bandpass filtering at 0.1--0.5 Hz with zero-crossing analysis for respiratory rate estimation. - Heart rate extraction (
HeartRateExtractor) -- Bandpass filtering at 0.8--2.0 Hz with autocorrelation peak detection and inter-subcarrier phase coherence weighting. - Anomaly detection (
VitalAnomalyDetector) -- Z-score analysis using Welford running statistics for real-time clinical alerts (apnea, tachycardia, bradycardia).
Results are stored in a VitalSignStore with configurable retention for historical trend
analysis.
Feature flags
| Flag | Default | Description |
|---|---|---|
serde |
yes | Serialization for vital sign types |
Quick Start
use wifi_densepose_vitals::{
CsiVitalPreprocessor, BreathingExtractor, HeartRateExtractor,
VitalAnomalyDetector, VitalSignStore, CsiFrame,
VitalReading, VitalEstimate, VitalStatus,
};
let mut preprocessor = CsiVitalPreprocessor::new(56, 0.05);
let mut breathing = BreathingExtractor::new(56, 100.0, 30.0);
let mut heartrate = HeartRateExtractor::new(56, 100.0, 15.0);
let mut anomaly = VitalAnomalyDetector::default_config();
let mut store = VitalSignStore::new(3600);
// Process a CSI frame
let frame = CsiFrame {
amplitudes: vec![1.0; 56],
phases: vec![0.0; 56],
n_subcarriers: 56,
sample_index: 0,
sample_rate_hz: 100.0,
};
if let Some(residuals) = preprocessor.process(&frame) {
let weights = vec![1.0 / 56.0; 56];
let rr = breathing.extract(&residuals, &weights);
let hr = heartrate.extract(&residuals, &frame.phases);
let reading = VitalReading {
respiratory_rate: rr.unwrap_or_else(VitalEstimate::unavailable),
heart_rate: hr.unwrap_or_else(VitalEstimate::unavailable),
subcarrier_count: frame.n_subcarriers,
signal_quality: 0.9,
timestamp_secs: 0.0,
};
let alerts = anomaly.check(&reading);
store.push(reading);
}
Architecture
wifi-densepose-vitals/src/
lib.rs -- Re-exports, module declarations
types.rs -- CsiFrame, VitalReading, VitalEstimate, VitalStatus
preprocessor.rs -- CsiVitalPreprocessor (EMA static suppression)
breathing.rs -- BreathingExtractor (0.1-0.5 Hz bandpass)
heartrate.rs -- HeartRateExtractor (0.8-2.0 Hz autocorrelation)
anomaly.rs -- VitalAnomalyDetector (Z-score, Welford stats)
store.rs -- VitalSignStore, VitalStats (historical retention)
Related Crates
| Crate | Role |
|---|---|
wifi-densepose-hardware |
Provides raw CSI frames from ESP32 |
wifi-densepose-mat |
Uses vital signs for survivor triage |
wifi-densepose-signal |
Advanced signal processing algorithms |
License
MIT OR Apache-2.0