{
  "registry": "KnowYourPrime Evidence Registry",
  "license": {
    "name": "CC BY 4.0",
    "url": "https://creativecommons.org/licenses/by/4.0/",
    "attribution": "Credit KnowYourPrime and link to the finding URL."
  },
  "fields": {
    "devices": "Devices this finding names, including models it says it does not cover. What was actually tested is in scope.applies_to; exclusions are in scope.does_not_cover.",
    "evidence": "Studies by role: anchor (the rating rests on it), conflicting, null_result, supporting.",
    "industry_ties": "Device-maker ties listed in Europe PMC metadata: author_affiliations names makers an author lists as an affiliation, funders names makers listed as funding. stated_ties holds ties a paper states only in its own conflict, funding or acknowledgement text, each read from that statement and worded to say only what it says. Sources are Europe PMC metadata, funding printed in the abstract, and those reviewed statements. An empty list means no tie was found there, not that the study is independent: many papers have no open full text to read. Metadata, not a judgment of the study. checked false means no Europe PMC metadata was available."
  },
  "id": "KYP-ER-0020",
  "version": "1.0",
  "reviewed": "2026-10-24",
  "url": "https://knowyourprime.com/evidence-smartwatch-cuff-blood-pressure-accuracy",
  "title": "Accuracy of Smartwatches With a Built-In Blood Pressure Cuff",
  "question": "Are smartwatches with a small inflatable cuff in the strap, such as the Huawei Watch D and D2 or Omron HeartGuide, accurate for blood pressure?",
  "measurement": "Blood pressure",
  "devices": [
    "Huawei Watch D",
    "Huawei Watch D2",
    "Omron HeartGuide"
  ],
  "rating": {
    "label": "Uncertain",
    "code": "uncertain",
    "definition": "Evidence is conflicting, inconsistent, or difficult to interpret.",
    "rule_version": "1.6",
    "rule_reasons": [
      "Anchor-grade evidence affirms the core relationship.",
      "An anchor study is present but its own reported finding does not cleanly affirm this claim, so it does not count toward the Established threshold.",
      "A clean anchor supports this claim, but an unresolved conflicting study contradicts it on the core relationship, so the evidence is treated as in genuine dispute."
    ]
  },
  "conclusion": "In standard validation tests, yes: the Huawei Watch D and D2 met the international accuracy standard for home monitors at rest. In independent tests on patients outside those protocols, no: in 41 hypertensive outpatients the Watch D2 underread systolic pressure by 6.8 mmHg on average, and in 100 patients from a real-world clinic sample none of three wrist watches, including the Omron HeartGuide, passed every criterion of the standard.",
  "reasoning": [
    "A watch with a real cuff measures pressure the way a home arm monitor does, by inflating and reading the pulse in the cuff, so it can be validated against the same AAMI/ESH/ISO standard. Three studies of the Huawei Watch D and D2 report that it met that standard at rest, one also in an ambulatory test, which are the clean anchors.",
    "Independent studies in patients contradict it. The European Society of Hypertension consensus found static validations generally acceptable but only two devices validated to established standards and little data for 24-hour use. With affirming anchors and core-hitting conflicts, the rule rates the claim Uncertain."
  ],
  "key_results": [
    {
      "text": "In the Huawei Watch D2 rest validation of 85 analyzed subjects, mean differences from reference readings were -1.6 ± 6.4 mmHg systolic and -1.9 ± 5.0 mmHg diastolic, meeting the AAMI/ESH/ISO universal standard.",
      "source": "doi:10.1038/s41440-025-02345-2",
      "source_url": "https://doi.org/10.1038/s41440-025-02345-2",
      "source_citation": "Zhou et al., Hypertension Research, 2025"
    },
    {
      "text": "Worn alongside a validated ambulatory monitor for 24 hours by 41 hypertensive outpatients, the Watch D2 underestimated systolic pressure with a mean bias of -6.8 mmHg and wide limits of agreement; systolic concordance was poor (ICC 0.38), and only 47 percent of systolic and 61 percent of diastolic readings fell within the agreement bands the study applied.",
      "source": "doi:10.1016/j.rceng.2026.502523",
      "source_url": "https://doi.org/10.1016/j.rceng.2026.502523",
      "source_citation": "Seoane-Casqueiro et al., Revista Clinica Espanola, 2026"
    },
    {
      "text": "Of 128 patients enrolled (median age 53, 46 percent on blood pressure medication) and 100 analyzed, the Bpro G2, Omron HeartGuide and Heartisans watches each had mean values within 5 mmHg of sphygmomanometry but none passed all ISO 81060-2 criteria, and the Omron watch underestimated systolic pressure by 8.46 mmHg in adjusted analyses.",
      "source": "doi:10.1007/s00392-023-02353-7",
      "source_url": "https://doi.org/10.1007/s00392-023-02353-7",
      "source_citation": "Lunardi et al., Clinical Research in Cardiology, 2024"
    }
  ],
  "scope": {
    "applies_to": "Wrist-watch blood pressure monitors with an inflatable cuff in the strap, at rest and over 24 hours, compared with validated cuff devices.",
    "does_not_cover": "Cuffless optical estimates, covered in separate findings; diagnosis or treatment decisions; devices not tested."
  },
  "limitations": [
    "The passing validations are of one manufacturer’s devices, and some independent tests used small samples.",
    "Validation protocols test resting, seated readings; real-world 24-hour wear adds movement and position changes."
  ],
  "evidence": {
    "anchor": [
      {
        "key": "doi:10.1097/hjh.0000000000004415",
        "title": "Wearable wrist-watch type cuff oscillometric blood pressure monitors: consensus statement by the European Society of Hypertension Working Group on blood pressure monitoring.",
        "first_author": "Stergiou",
        "journal": "Journal of hypertension",
        "year": 2026,
        "url": "https://doi.org/10.1097/HJH.0000000000004415",
        "industry_ties": {
          "checked": true,
          "author_affiliations": [],
          "funders": [],
          "stated_ties": []
        }
      },
      {
        "key": "doi:10.1111/jch.70183",
        "title": "Accuracy and Reduced Sleep Disruption of a Wearable Smartwatch for Nocturnal Blood Pressure Monitoring: A Validation Study.",
        "first_author": "Liu",
        "journal": "Journal of clinical hypertension (Greenwich, Conn.)",
        "year": 2025,
        "url": "https://doi.org/10.1111/jch.70183",
        "industry_ties": {
          "checked": true,
          "author_affiliations": [],
          "funders": [
            "Huawei"
          ],
          "stated_ties": []
        }
      },
      {
        "key": "doi:10.1038/s41440-025-02345-2",
        "title": "Accuracy of a wearable watch-type oscillometric blood pressure monitor in rest and ambulatory blood pressure measurements.",
        "first_author": "Zhou",
        "journal": "Hypertension research : official journal of the Japanese Society of Hypertension",
        "year": 2025,
        "url": "https://doi.org/10.1038/s41440-025-02345-2",
        "industry_ties": {
          "checked": true,
          "author_affiliations": [],
          "funders": [],
          "stated_ties": []
        }
      },
      {
        "key": "doi:10.1097/mbp.0000000000000608",
        "title": "Validation of the watch-type HUAWEI WATCH D oscillometric wrist blood pressure monitor in adult Chinese.",
        "first_author": "Zhang",
        "journal": "Blood pressure monitoring",
        "year": 2022,
        "url": "https://doi.org/10.1097/MBP.0000000000000608",
        "industry_ties": {
          "checked": true,
          "author_affiliations": [],
          "funders": [],
          "stated_ties": []
        }
      }
    ],
    "conflicting": [
      {
        "key": "doi:10.1016/j.rceng.2026.502523",
        "title": "Clinical reliability of a wrist-worn oscillometric ambulatory blood pressure monitor: an independent agreement evaluation.",
        "first_author": "Seoane-Casqueiro",
        "journal": "Revista clinica espanola",
        "year": 2026,
        "url": "https://doi.org/10.1016/j.rceng.2026.502523",
        "industry_ties": {
          "checked": true,
          "author_affiliations": [],
          "funders": [],
          "stated_ties": []
        }
      },
      {
        "key": "doi:10.1113/ep093286",
        "title": "Comparison of blood pressure measurements between the Huawei Watch D smartwatch application and the validated Omron M3 Intellisense device: Observational study.",
        "first_author": "Velázquez Saornil",
        "journal": "Experimental physiology",
        "year": 2026,
        "url": "https://doi.org/10.1113/EP093286",
        "industry_ties": {
          "checked": true,
          "author_affiliations": [],
          "funders": [],
          "stated_ties": []
        }
      },
      {
        "key": "doi:10.1007/s00392-023-02353-7",
        "title": "Performance of wearable watch-type home blood pressure measurement devices in a real-world clinical sample.",
        "first_author": "Lunardi",
        "journal": "Clinical research in cardiology : official journal of the German Cardiac Society",
        "year": 2024,
        "url": "https://doi.org/10.1007/s00392-023-02353-7",
        "industry_ties": {
          "checked": true,
          "author_affiliations": [],
          "funders": [],
          "stated_ties": []
        }
      }
    ],
    "supporting": [
      {
        "key": "doi:10.1038/s41440-025-02410-w",
        "title": "The quest for accurate wearable blood pressure monitors.",
        "first_author": "Stergiou",
        "journal": "Hypertension research : official journal of the Japanese Society of Hypertension",
        "year": 2026,
        "url": "https://doi.org/10.1038/s41440-025-02410-w",
        "industry_ties": {
          "checked": true,
          "author_affiliations": [],
          "funders": [],
          "stated_ties": []
        }
      },
      {
        "key": "doi:10.3390/s23218877",
        "title": "WATCH-BPM-Comparison of a WATCH-Type Blood Pressure Monitor with a Conventional Ambulatory Blood Pressure Monitor and Auscultatory Sphygmomanometry.",
        "first_author": "Vaseekaran",
        "journal": "Sensors (Basel, Switzerland)",
        "year": 2023,
        "url": "https://doi.org/10.3390/s23218877",
        "industry_ties": {
          "checked": true,
          "author_affiliations": [],
          "funders": [],
          "stated_ties": []
        }
      }
    ]
  },
  "evidence_last_evaluated": "Oct 19, 2026",
  "rating_history": [
    {
      "date": "2026-10-19",
      "rating": "Uncertain",
      "from": null,
      "rule_version": "1.6"
    }
  ],
  "versions": [
    {
      "version": "1.0",
      "date": "2026-10-24",
      "rating": "Uncertain",
      "change": "First published."
    }
  ],
  "research_desk": "https://knowyourprime.com/research-desk-blood-pressure#wrist_cuff_accuracy",
  "related_findings": [
    "https://knowyourprime.com/evidence-cuffless-blood-pressure-at-night",
    "https://knowyourprime.com/evidence-calibrated-cuffless-blood-pressure-tracking"
  ],
  "related_articles": [
    "https://knowyourprime.com/can-a-smartwatch-measure-blood-pressure",
    "https://knowyourprime.com/blood-pressure-by-age"
  ],
  "methodology": "https://knowyourprime.com/methodology",
  "citation": "KnowYourPrime Evidence Registry, Finding KYP-ER-0020, version 1.0, reviewed 2026-10-24. https://knowyourprime.com/evidence-smartwatch-cuff-blood-pressure-accuracy"
}