Respiratory · LIVE

Rapid shallow breathing index (RSBI)

Rapid shallow breathing index

Compute the Yang and Tobin rapid shallow breathing index as respiratory rate in breaths/min divided by tidal volume in liters.

LIVE $0.005 USDC GET /api/calc/rsbi

Markdown: /docs/rsbi.md · Canonical: https://magentlab.com/docs/rsbi

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Compute the Yang and Tobin rapid shallow breathing index as respiratory rate in breaths/min divided by tidal volume in liters.

When to use

When an agent needs f/VT with VT in liters and must not invent a wean order or perform an SBT.

When not to use

• Not a wean order and not a diagnosis.
• Measured during spontaneous breathing as published (Yang and Tobin 1991).
• Not a ventilator-derived index unless the caller supplies frequency (f) and tidal volume (VT).
• Magent does not perform a spontaneous breathing trial (SBT).

Formula

rsbi = respiratory_rate / tidal_volume_l

Citation

Title

A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation

Authors

Yang KL, Tobin MJ

Source

N Engl J Med. 1991;324(21):1445-1450

DOI

10.1056/NEJM199105233242101

Worked example

Also searched as

• RSBI
• rapid shallow breathing index
• Yang Tobin index
• f/VT
• frequency over tidal volume
• Tobin RSBI
• rapid shallow breathing
• breaths per minute per liter

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/rsbi?respiratory_rate=20&tidal_volume_ml=400

Full URL: https://api.magentlab.com/api/calc/rsbi?respiratory_rate=20&tidal_volume_ml=400

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/rsbi?respiratory_rate=20&tidal_volume_ml=400"

Parameters

Bulk (POST)

POST the same path with a JSON items array. Price is n times the GET unit. Invalid items return HTTP 400 before settlement.

POST /api/calc/rsbi Max 25 unit_amount * n PREVIEW

• 1 to 25 items. Each item uses the same keys as the GET query parameters.
• The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
• HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
• Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
• x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "respiratory_rate": "20",
      "tidal_volume_ml": "400"
    },
    {
      "respiratory_rate": "20",
      "tidal_volume_ml": "400"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/rsbi",
  "items": [
    {
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Yang KL, Tobin MJ",
        "doi": "10.1056/NEJM199105233242101",
        "id": "yang-tobin-1991",
        "source": "N Engl J Med. 1991;324(21):1445-1450",
        "title": "A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation"
      },
      "formula": "rsbi",
      "formula_expression": "rsbi = respiratory_rate / tidal_volume_l",
      "respiratory_rate": 20,
      "rsbi": 50.0,
      "rsbi_gt_105": false,
      "tidal_volume_l": 0.4
    },
    {
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Yang KL, Tobin MJ",
        "doi": "10.1056/NEJM199105233242101",
        "id": "yang-tobin-1991",
        "source": "N Engl J Med. 1991;324(21):1445-1450",
        "title": "A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation"
      },
      "formula": "rsbi",
      "formula_expression": "rsbi = respiratory_rate / tidal_volume_l",
      "respiratory_rate": 20,
      "rsbi": 50.0,
      "rsbi_gt_105": false,
      "tidal_volume_l": 0.4
    }
  ]
}

Response

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "citation": {
    "authors": "Yang KL, Tobin MJ",
    "doi": "10.1056/NEJM199105233242101",
    "id": "yang-tobin-1991",
    "source": "N Engl J Med. 1991;324(21):1445-1450",
    "title": "A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation"
  },
  "formula": "rsbi",
  "formula_expression": "rsbi = respiratory_rate / tidal_volume_l",
  "respiratory_rate": 20,
  "rsbi": 50.0,
  "rsbi_gt_105": false,
  "tidal_volume_l": 0.4
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

Related tools

• Oxygenation index — Compute the oxygenation index from inspired oxygen fraction, mean airway pressure in cm H2O, and arterial PO2.
• PaO2/FiO2 ratio — Compute the PaO2/FiO2 ratio as arterial PO2 in mm Hg divided by inspired oxygen fraction.

Payment

Required query parameters must be present and valid. Invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

• Invalid query parameters return HTTP 400 before settlement. You are not charged.
• Settlement finishes before the tool executes (paymentFlow upfront). Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
• HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
• Execution is timeout-bounded and concurrency-capped.
• Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.