What do the rules and sources say?
- V3 framework (DiMe, 2020). Goldsack et al. defined three components for Biometric Monitoring Technologies (BioMeTs): verification (sample-level sensor outputs tested in silico/in vitro), analytical validation (algorithms turning sensor data into physiological/behavioral metrics, tested in humans against a reference), and clinical validation (whether the measure identifies, measures or predicts a clinically meaningful state in a defined context of use) (npj Digital Medicine, 2020).
- V3+ (2024). DiMe extended V3 with a fourth component, usability validation: can intended users use the device, app, instructions and workflow correctly in real use contexts (npj Digital Medicine, 2024; DiMe). DiMe's sDHT Adoption Navigator describes it as starting with a use specification and use-related risk analysis, then formative testing and a summative human-factors validation (DiMe Navigator).
- FDA DHT guidance (Dec 2023). "Digital Health Technologies for Remote Data Acquisition in Clinical Investigations" (final, December 2023) is FDA's reference guidance on using DHTs to collect data remotely in drug/biologic/device trials, including verification and validation that a DHT is fit for purpose (FDA).
- Consumer heart-rate standards (CTA). ANSI/CTA-2065-A, "Physical Activity Monitoring for Heart Rate," sets definitions and performance criteria for wearable heart-rate measurement under constrained lab conditions and applies to PPG-based wearables (CTA). ANSI/CTA-2065.1-2023 covers real-world (naturalistic) analysis (CTA; ANSI webstore). These are voluntary consumer standards, not FDA requirements.
- Blood pressure: ISO 81060-2. ISO 81060-2 sets requirements for the clinical investigation of non-invasive sphygmomanometers with automated measurement (ISO).
- Pulse oximetry and skin tone. FDA says "current scientific evidence suggests there are some accuracy differences in pulse oximeter performance between individuals with lighter and darker skin pigmentation" (FDA press release, Jan 6, 2025).
- FDA draft guidance (Jan 7, 2025). "Pulse Oximeters for Medical Purposes – Non-Clinical and Clinical Performance Testing, Labeling, and Premarket Submission Recommendations" (FDA; Federal Register 90 FR 1150). Key proposals: clinical data such as controlled desaturation studies or, in some cases, real-world data across the skin-tone range; more study participants; both the subjective Monk Skin Tone scale and the objective Individual Typology Angle (ITA); and a prominent labeling statement for devices shown to perform comparably across skin tones (FDA press release). Studies must report MST and ITA values per participant and the percentage in each MST group who tolerated desaturation down to SaO2 70% (draft PDF). Comments were due Mar 10, 2025, under docket FDA-2023-N-4976.
- Status as of Oct 2026. FDA's guidance page still labels the document a draft ("Not for implementation"). Once final, it will supersede the 2013 pulse oximeter 510(k) guidance (FDA pulse oximeters page).
What does it mean for startups?
- Plan V3+ early. Investors, pharma sponsors and FDA reviewers increasingly expect separate evidence for each layer: sensor verification, algorithm analytical validation, clinical validation and usability. A "validated" claim with no context of use is weak.
- Pick the right reference standard. For example, use ECG for heart rate, arterial SaO2 for SpO2 and an auscultatory or intra-arterial reference for BP. Then pre-specify accuracy metrics (bias, limits of agreement, MAPE, Arms).
- Diversity is now a design input. Following FDA's pulse-ox draft, skin-tone stratification (MST + ITA) is becoming the de facto expectation for any optical (PPG/SpO2) sensor, not just oximeters. This is our inference, not FDA's stated scope.
- Consumer vs. medical claims. CTA standards help with consumer credibility. Medical claims bring in FDA device requirements.
- Trial use. Sponsors using a wearable as a trial endpoint will review it against FDA's 2023 DHT guidance, whether or not the device is cleared.
Sources
- Goldsack et al., V3, npj Digit Med 2020 — https://www.nature.com/articles/s41746-020-0260-4
- V3+, npj Digit Med 2024 — https://www.nature.com/articles/s41746-024-01322-2
- DiMe V3+ — https://dimesociety.org/v3/ ; Navigator — https://navigator.dimesociety.org/your-validation-strategy/4-2-usability-validation/
- FDA DHT remote data acquisition guidance (Dec 2023) — https://www.fda.gov/regulatory-information/search-fda-guidance-documents/digital-health-technologies-remote-data-acquisition-clinical-investigations
- ANSI/CTA-2065-A — https://www.cta.tech/standards/ansicta-2065-a/ ; CTA-2065.1 — https://www.cta.tech/standards/ansicta-20651/
- ISO 81060-2 — https://www.iso.org/standard/73339.html
- FDA pulse oximeter draft guidance — https://www.fda.gov/regulatory-information/search-fda-guidance-documents/pulse-oximeters-medical-purposes-non-clinical-and-clinical-performance-testing-labeling-and
- FDA press release Jan 6, 2025 — https://www.fda.gov/news-events/press-announcements/fda-proposes-updated-recommendations-help-improve-performance-pulse-oximeters-across-skin-tones
- Federal Register notice — https://www.govinfo.gov/content/pkg/FR-2025-01-07/html/2024-31540.htm
- FDA pulse oximeters page — https://www.fda.gov/medical-devices/products-and-medical-procedures/pulse-oximeters