ZPE-Bio

ECG codec, beta. Clinical-mode fidelity-bounded-lossy ECG archival format covering the deterministic PRD <= 2.32% reconstruction contract that lossless byte compressors structurally cannot offer. Shipped as a Python CLI, a Rust core crate, and committed validation artifacts. This README is intentionally limited to claims that are backed by proof artifacts already on disk and by tests that run in CI. ZPE-Bio is one of 17 independent encoding products in the Zer0pa portfolio, each developed for its own domain.

This repo's claimed surface is the clinical-mode ECG fidelity contract only. It does not use the wearable runbooks as release evidence, and it does not make a generalized biosignal or regulatory claim. Scope is bounded to CPU-only Python codec; no hardware acceleration path is implied.

Headline metric: MIT-BIH 48/48 integrity, mean PRD 1.12%, mean SNR 43.3 dB. Backed by proof artifact at validation/results/BENCHMARK_SUMMARY.md and validation/results/mitdb_python_only/mitdb_aggregate.json.

Honest blocker: PTB-XL max PRD reaches 5.29% (100-record sample) — above the clinical 2.32% contract threshold. This is an open boundary; PTB-XL is logged but not claimed under the clinical fidelity contract.

Field	Value
Architecture	BIO_STREAM
Encoding	BIO_DELTA_V1

What This Is

ECG codec, beta. Clinical-mode fidelity-bounded-lossy ECG archival format. The product is the deterministic PRD <= 2.32% reconstruction contract that lossless byte compressors structurally cannot offer. Shipped as a Python CLI, a Rust core crate, and committed validation artifacts.

This repo's claimed surface is the clinical-mode ECG fidelity contract only. It does not use the wearable runbooks as release evidence, and it does not make a generalized biosignal or regulatory claim. ZPE-Bio is one of 17 independent encoding products in the Zer0pa portfolio, each developed for its own domain.

Field	Value
Architecture	BIO_STREAM
Encoding	BIO_DELTA_V1

Key Metrics

All runs are CPU-only Python codec. Full per-database detail appears in the detailed subsections below.

Database	Records	Integrity	Mean PRD	Mean SNR
MIT-BIH Arrhythmia (mitdb)	48/48	100%	1.12%	43.3 dB
MIT-BIH Noise Stress (nstdb)	15/15	100%	—	60.5 dB
European ST-T (edb)	90/90	100%	—	52.5 dB
PTB-XL (100-record sample)	100/100	100%	—	32.0 dB

Source artifacts: validation/results/BENCHMARK_SUMMARY.md, validation/results/mitdb_python_only/mitdb_aggregate.json, validation/results/ptbxl/summary.json, validation/results/nstdb/summary.json, validation/results/edb/summary.json

Competitive Benchmarks

ZPE-Bio is a fidelity-bounded-lossy ECG codec (clinical mode, mean PRD ~1.12%, max PRD <= 2.32% on MIT-BIH). gzip, zlib, and zstd are general-purpose lossless byte compressors. Direct compression-ratio comparison is not apples-to-apples: ZPE-Bio's CR is intrinsically bounded by its clinical fidelity contract, while lossless compressors achieve whatever CR the byte distribution permits at zero error. The honest comparison reports both CRs and the fidelity contract, not a single "winner".

Codec	Mean CR	Median CR	Fidelity
ZPE-Bio	1.323	1.316	bounded-lossy, PRD <= 2.32% (mean ~1.12%)
gzip (level 6)	1.429	1.408	lossless
zlib (level 6)	1.429	1.408	lossless
zstd (level 3)	1.412	1.394	lossless

On raw compression ratio alone, ZPE-Bio (mean CR 1.323) loses to gzip, zlib, zstd (gzip 1.429, zlib 1.429, zstd 1.412). This is expected and does not invalidate the lane: ZPE-Bio is a fidelity-bounded-lossy clinical ECG codec (mean PRD ~1.12%, max PRD <= 2.32% on MIT-BIH); gzip/zlib/zstd are lossless general-purpose compressors. The two are not commensurable as a single CR number. ZPE-Bio's value proposition is deterministic, bounded-error reconstruction with a clinical fidelity contract, not raw CR supremacy over lossless byte compressors.

Note on input scope: lossless comparator CRs above are computed over the full raw int16 .dat byte stream of each MIT-BIH record; ZPE-Bio CRs are taken from the lane's existing aggregate, computed over a 10000-sample clinical-mode window per record. Both surfaces are recorded in the proof artifact below.

Proof: proofs/artifacts/comp_benchmarks/mitbih_codec_comparison.json

What We Prove

• MIT-BIH 48/48 records processed with 100% integrity pass rate, mean PRD 1.12%, mean SNR 43.3 dB, max PRD 2.32% — within clinical contract.
• MIT-BIH Noise Stress 15/15 records, 100% integrity, mean SNR 60.5 dB, max PRD 1.96%.
• European ST-T 90/90 records, 100% integrity, mean SNR 52.5 dB.
• PTB-XL 100/100 records (sample), 100% integrity.
• Python and Rust codec implementations are parity-gated in CI.
• Deterministic round-trip replay is CI-anchored.

What We Don't Claim

• No public release-readiness verdict
• No generalized biosignal victory claim
• No Bio Wearable closure claim
• No regulatory or FDA claim

Commercial Readiness

Field	Value
Verdict	STAGED
Commit SHA	see CI badge
Confidence	MEDIUM — clinical-mode MIT-BIH contract met; PTB-XL max PRD exceeds 2.32% threshold (open boundary); regulatory alignment deferred
Source path	validation/results/BENCHMARK_SUMMARY.md

Tests and Verification

python -m venv .venv
source .venv/bin/activate
python -m pip install --upgrade pip
python -m pip install -e ".[dev,validation]"
pytest -q
python -m build

Quick ECG smoke check:

python -m zpe_bio roundtrip --mode clinical --samples 250

Proof Anchors

Claim	Proof Artifact On Disk	CI Test Anchor
MIT-BIH benchmark writer emits summary + aggregate artifacts	validation/results/BENCHMARK_SUMMARY.md, validation/results/mitdb_python_only/mitdb_aggregate.json	tests/test_benchmark_mitdb.py
PTB-XL benchmark writer emits committed-style summary artifacts	validation/results/ptbxl/summary.json	tests/test_benchmark_physionet.py
Clinical ECG round-trip remains deterministic and high-fidelity in the Python codec	validation/results/BENCHMARK_SUMMARY.md	tests/test_codec.py, tests/test_deterministic_replay.py
Python and Rust codec implementations remain parity-gated in CI	core/rust/, tests/test_parity.py	tests/test_parity.py

Repo Shape

• python/zpe_bio/: Python package and CLI
• core/rust/: Rust codec crate
• embedded/: embedded reference firmware tree
• tests/: repo-local pytest suite
• scripts/: benchmark and operator scripts
• validation/results/: committed benchmark outputs
• validation/runbooks/: execution and boundary runbooks
• docs/: repo documentation and regulatory/reference material

Quick Start

python -m venv .venv
source .venv/bin/activate
pip install -e ".[dev,validation]"
python -m zpe_bio roundtrip --mode clinical --samples 250

Further reading:

• validation/results/README.md
• validation/results/BENCHMARK_SUMMARY.md
• docs/ARCHITECTURE.md
• docs/LEGAL_BOUNDARIES.md

---

MIT-BIH Arrhythmia Database (48 records, full corpus)

Metric	Value
Records processed	48/48
Integrity pass rate	48/48 (100%)
Mean compression ratio	1.323
Mean SNR	43.3 dB
Mean RMSE	3.24 uV
Mean PRD	1.12%
Max PRD	2.32%

Source: validation/results/BENCHMARK_SUMMARY.md, validation/results/mitdb_python_only/mitdb_aggregate.json | CI: tests/test_benchmark_mitdb.py

MIT-BIH Noise Stress Test Database (nstdb, 15 entries)

Metric	Value
Records processed	15/15
Integrity pass rate	15/15 (100%)
Mean compression ratio	1.310
Mean SNR	60.5 dB
Max PRD	1.96%

Source: validation/results/nstdb/summary.json | CI: tests/test_benchmark_physionet.py

European ST-T Database (edb, 90 entries)

Metric	Value
Records processed	90/90
Integrity pass rate	90/90 (100%)
Mean compression ratio	1.376
Mean SNR	52.5 dB
Max PRD	4.34%

Source: validation/results/edb/summary.json | CI: tests/test_benchmark_physionet.py

PTB-XL ECG Database (100 records sample)

Metric	Value
Records processed	100/100
Integrity pass rate	100/100 (100%)
Mean compression ratio	1.576
Mean SNR	32.0 dB
Max PRD	5.29%

Source: validation/results/ptbxl/summary.json | CI: tests/test_benchmark_physionet.py

Note on PTB-XL SNR/PRD: PTB-XL records are 12-lead 500 Hz clinical studies; the lower SNR relative to MIT-BIH reflects higher signal diversity and more channels compressed per segment, not codec regression. Integrity passes 100/100.

Upcoming Workstreams

This section captures the active lane priorities — what the next agent or contributor picks up, and what investors should expect. Cadence is continuous, not milestoned.

• Rust embedded encode/decode path — Active Engineering. Wearable-cardiac-monitor wedge requires sub-ms latency and constrained-resource execution; foundation primitives are mature.
• Regulatory alignment scoping (IEC 60601 / FDA) — Research-Deferred — Investigation Underway. The PRD-bounded fidelity contract is a regulatory moat that lossless coders cannot match; alignment work scopes the path to clinical submission.