Acoustic Breath Biomarker Tracker

This experimental helper calculates a pause ratio from synthetic, pre-segmented durations. It does not capture audio, run VAD, detect a medical condition, assess patient safety, or execute a handoff. Its DYSPNEA_DETECTED, NORMAL, and action enums are illustrative legacy labels, not clinical conclusions. Do not use this prototype for patient triage or emergency decisions.

Scientific Foundation

Paper / Framework	Source	Relevance
Detection of Mild Dyspnea from Pairs of Speech Recordings	IEEE ICASSP (2020)	Provides the acoustic feature extraction models for identifying respiratory variations and abnormal pause mechanics.
Biomarkers in respiratory diseases	Breathe editorial (2019)	General background, not validation of pause-ratio clinical inference.
COVID-19-related voice disorders: a scoping review	PubMed (2026)	Background on voice disorders, not validation of this helper.
Software as a Medical Device (SaMD)	FDA (2023)	Regulatory framework for AI algorithms evaluating biological states.

How it works

1. Supply synthetic AudioSegment durations to the helper.
2. Audio capture and VAD are not included; any future host would provide its own inputs.
3. The process_call_stream function evaluates the extracted segments.
4. A pause ratio at or above the illustrative threshold selects the legacy DYSPNEA_DETECTED enum; it does not establish dyspnea.
5. ESCALATE_TO_HUMAN is returned as a demo label only. No workflow is halted and no nurse transfer or emergency handoff occurs.

Decision Matrix

Pause Ratio	Classification	Recommended Action
>= 0.40	DYSPNEA_DETECTED	ESCALATE_TO_HUMAN
< 0.40	NORMAL	PROCEED_NORMALLY
Ratio < 0 (no data)	INSUFFICIENT_DATA	INDETERMINATE

Configuration Reference

Parameter	Default	Range	Description
pause_threshold_ratio	0.40	0.30 - 0.60	Ratio of pause time over total time to trigger dyspnea flag.
segment_duration_ms	500	250 - 2000	Window size for acoustic feature extraction.

Expected Outcomes & Metrics

The figures below are unvalidated design aspirations, not clinical sensitivity, specificity, or handoff guarantees.

Metric	Target	Notes
Escalation Latency	< 1 second	Critical for emergency health response.
False Positive Rate (FPR)	< 5%	Legitimate pauses shouldn't trigger an emergency.
False Negative Rate (FNR)	< 2%	Must not miss severe respiratory distress.

Limitations & Known Constraints

• Codec Degradation: Low-bitrate connections may obscure acoustic pauses or falsely introduce silence gaps (packet loss).
• Background Noise: Heavy environmental noise might be misclassified as speech by VAD, lowering the calculated pause ratio.
• Not a Clinical Tool: This is not a diagnostic or patient-triage mechanism. Low scores do not establish that a person is safe.

Possible Future Research Contexts

These contexts require separate clinical evaluation and human-governed systems; they are not supported patient-care uses of this prototype.

• Post-discharge monitoring for COPD or heart failure patients.
• Daily check-in phone calls for patients with severe asthma.
• Triage in automated telehealth intake systems.

Integration

No dialogue-model or telephony integration is included. For a future host, this numeric demonstration must not delay human review or override an explicit report of distress.