# 📐 L2 Spec — Intravascular Ultrasound (IVUS) Mismatch-Only Spec
**ID:** `L2-061-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-061`](/artifact/l1/L1-061)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.5 · **Delta tier:** 5
> **⛓ On-chain block:** 41552980
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| F mhz | MHz | 20 – 60 |
| Snr db | dB | 0.0 – 40.0 |
| N lines | — | 64 – 1024 |
| Depth mm | mm | 2 – 20 |
| Blood speckle | — | 0.0 – 0.3 |
| Catheter motion | — | 0.0 – 0.5 |
| Guidewire artifact | — | 0.0 – 0.3 |
| Non uniform rotation | — | 0.0 – 0.3 |
## 2. Tolerance (ε)
**Type:** `fn`
```
16.0 + 0.3 * SNR_dB - 8.0 * catheter_motion - 6.0 * non_uniform_rotation - 4.0 * blood_speckle
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.5 |
| Delta tier | 5 |
## 4. Fingerprint
`74b86693cdc678723ebb21fe460c9c1b16ee15b355d42253487d790762ed9495`
## 5. On-chain Registration
- **Chain hash:** `0x930f96a74cacba61c22d38a72f98b8212a17afa049aa8c7fbaadcecec4ff9eac`
- **Chain tx hash:** `0x2c71d4f424f414ea47fadaf022d669ae58090bdd6f19a6ea6e0a6f041a118d8d`
- **Chain block:** `41552980`
---
## File Mapping
This bundle consists of: `L2-061-001.md`, `L2-061-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-061-001.md` | Source of truth — edit this | Human or LLM |
| `L2-061-001.json` | Structured metadata for the registry | LLM regenerates from the sections above |
**Prompt for your LLM after editing this Markdown:**
> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.
_This Markdown was auto-synthesized from the catalog row for `L2-061-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._