Decide your claims before you decide on hardware. 21 CFR 870.2700 defines an oximeter as a device that transmits radiation at known wavelengths through blood, and classifies it Class II. FDA issued draft guidance on pulse oximeters for medical purposes on January 7, 2025. Ask regulatory counsel how your claim maps to these texts.
Product managers building a ring or watch may be asked to add SpO2. This guide lists what the official sources say, what to measure on your own board, and what to ask before you choose.
This is an engineering summary of public sources for general wellness products. It covers general wellness products only and gives no legal advice. It contains no Duobay price and no measured result.
What do the official sources say?
Each row quotes the source text from the official page. Pages were read on October 31, 2026.
| Topic | Quoted text | What it means for the build | Source |
|---|---|---|---|
| Oximeter definition | "An oximeter is a device used to transmit radiation at a known wavelength(s) through blood" | The definition describes what the device does: radiation at known wavelengths through blood. Ask counsel how your sensor and claims map to it. | 21 CFR 870.2700 (Cornell LII), as of October 31, 2026 |
| Classification | "Class II (performance standards)." | The regulation classifies oximeters as Class II. | 21 CFR 870.2700 (Cornell LII), as of October 31, 2026 |
| Skin pigmentation | "Ongoing concerns that pulse oximeters may be less accurate in individuals with darker skin pigmentation." | FDA lists this as an open concern on its pulse oximeter page. | FDA pulse oximeter page, as of October 31, 2026 |
| Draft guidance | "On January 7, 2025, the FDA issued the draft guidance:" | The FDA page calls it draft guidance. | FDA pulse oximeter page, as of October 31, 2026 |
| Draft guidance scope | "including devices with a pulse oximeter function that estimates the amount of oxygen in arterial blood and pulse rate." | The scope is pulse oximeters for medical purposes. | FDA draft guidance page, as of October 31, 2026 |
| General wellness policy | "compliance policy for low risk products that promote a healthy lifestyle (general wellness products)" | The quoted policy text describes low risk products that promote a healthy lifestyle. Read the full guidance document on the FDA page, and ask counsel how it applies to an SpO2 claim. | FDA general wellness guidance page, as of October 31, 2026 |
The Cornell host is a secondary copy of the regulation, so re-check the text against the eCFR before you rely on it.
What should you test on your own board?
Nothing in the public sources gives you your accuracy, power draw or fit sensitivity. Decide each pass line yourself and write down the basis for it.
| What to test | How to instrument or collect | Raw data to record |
|---|---|---|
| Average current of the red/IR channel | Put a current meter or power analyzer on the battery rail. Capture the feature running, the feature off, and the whole device idle. | Raw current traces, sampling settings, LED drive settings, firmware version, temperature of the room. |
| Battery impact over your usage profile | Run a full day of your real profile with the feature on and with it off. Log battery voltage over time. | Voltage versus time logs for both runs, the profile you used, the cell lot. |
| Signal across skin tones | Wear the prototype on a range of volunteers who consented to the test. Use a reference device your team chose and documented, recording both readings at the same moment. | Paired readings, a skin-tone description method you defined and wrote down, fit and placement notes, ambient light notes. |
| Motion and fit sensitivity | Repeat the capture at rest, during light movement and with the device slightly loose. Mark each segment. | Raw optical signals, accelerometer data, segment labels, fit notes. |
| Ambient light rejection | Run the capture with the sensor lightly shielded and then in bright indoor light and near a window. | Raw signals for each condition, light source description, enclosure revision. |
| Claims text against behavior | List every string in the app, packaging and web page that mentions oxygen, SpO2 or blood. Compare each with what the device actually measured. | The full string list with locations, reviewer notes, counsel feedback. |
What should you ask before you choose?
Take this list to your team and to your regulatory counsel.
- Are we adding SpO2 to this product at all, and who signed off on that decision?
- Does a customer expect us to detect a condition? If yes, take that to regulatory counsel before you go further.
- Has regulatory counsel reviewed the exact claim text, including the app and packaging copy?
- Do we have a written skin-tone test plan, and who owns it?
- Has the battery effect of the red/IR channel been measured on our board?
- If FDA guidance changes, how does our firmware, labeling and app copy get updated on units already sold?
- What do we show the user when the signal is poor, and does it avoid implying a clinical reading?
- Can we ship a first version without SpO2 and add it in a later hardware revision?
Questions about SpO2 in a wellness wearable
Does FDA say SpO2 in a wellness wearable is allowed?
The quoted text on the FDA general wellness page (FDA, as of October 31, 2026) describes a compliance policy for low risk products that promote a healthy lifestyle. That text alone does not settle whether an SpO2 feature qualifies. Read the full guidance document on that page, and ask regulatory counsel about your specific claim.
Is the pulse oximeter draft guidance final?
The FDA page we read calls it draft guidance (FDA, as of October 31, 2026). Check the page for its current status before you rely on it.
Why does skin tone matter for a ring or watch sensor?
FDA lists ongoing concern that pulse oximeters may be less accurate in individuals with darker skin pigmentation. Any red/IR product should have a written test plan that covers a range of skin tones.
Is this page legal advice?
No. It is an engineering summary of public sources for general wellness products. You can tell us about your device to start a conversation.
If you are weighing SpO2 for a ring or watch, tell us about your device. You can also read about our health wearable development.
Sources
All pages accessed October 31, 2026. Re-read them before you decide. These are the official texts. The summaries are ours.
- 21 CFR 870.2700, Oximeter (Cornell LII copy): https://www.law.cornell.edu/cfr/text/21/870.2700 (accessed 2026-10-31)
- FDA, Pulse Oximeters: https://www.fda.gov/medical-devices/products-and-medical-procedures/pulse-oximeters (accessed 2026-10-31)
- FDA, Pulse Oximeters for Medical Purposes draft guidance: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/pulse-oximeters-medical-purposes-non-clinical-and-clinical-performance-testing-labeling-and (accessed 2026-10-31)
- FDA, General Wellness: Policy for Low Risk Devices: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/general-wellness-policy-low-risk-devices (accessed 2026-10-31)
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