Understanding Blood Oxygen Monitoring on the Apple Watch Ultra 1
A Comprehensive Look at the Feature and Recent Changes
Key Highlights Regarding Apple Watch Ultra 1 and Blood Oxygen Monitoring:
- Original Capability: The Apple Watch Ultra 1 was initially released with the capability to measure blood oxygen levels using its built-in sensor and the Blood Oxygen app.
- Impact of Legal Dispute: Due to a patent dispute, Apple has disabled the blood oxygen monitoring feature via software on new Apple Watch Series 9 and Ultra 2 models sold in the United States since January 18, 2024.
- Status of Ultra 1: Apple Watch Ultra 1 models purchased before January 18, 2024, or those with a model number ending in LL/A (indicating they were not subject to the software disablement) generally retain the blood oxygen functionality.
The Apple Watch Ultra 1: Designed with Blood Oxygen Monitoring
When the Apple Watch Ultra 1 was first introduced, a key feature highlighted was its ability to measure blood oxygen saturation (SpO2) directly from the wrist. This was made possible by a sensor built into the watch and the accompanying Blood Oxygen app. This functionality was designed to provide users with on-demand measurements and periodic background readings, offering insights into their respiratory well-being. The feature was available on Apple Watch Series 6 and later models, including the original Ultra.
How the Blood Oxygen Measurement Works
The blood oxygen sensor on the Apple Watch uses red and infrared light to determine the percentage of oxygen carried by red blood cells from the lungs to the rest of the body. The process involves shining light through the skin and measuring the amount of light reflected back. Oxygenated blood absorbs more infrared light, while deoxygenated blood absorbs more red light. By analyzing these light levels, the watch can estimate the SpO2 level.
For accurate measurements, Apple recommends ensuring the watch is worn snugly on the wrist, with the back of the watch flush against the skin. Factors like skin perfusion, motion, and ambient light can affect the accuracy of the readings. While the feature is a valuable wellness tool, Apple explicitly states that the measurements are not intended for medical use.
The Impact of the Patent Dispute on Apple Watch Features
A significant development impacting the availability of the blood oxygen feature on certain Apple Watch models is the legal dispute between Apple and the medical technology company Masimo. This dispute revolves around alleged infringement of patents related to pulse oximetry technology.
Disabling the Feature in New Models
As a result of this legal battle and a ruling by the U.S. International Trade Commission (ITC), Apple made the decision to disable the blood oxygen monitoring functionality on new Apple Watch Series 9 and Apple Watch Ultra 2 models sold in the United States starting from January 18, 2024. This disablement is implemented through a software workaround, meaning the physical sensor is still present in the watches, but the software needed to utilize it is not enabled.
Identifying Affected Models
For models sold in the United States after January 18, 2024, Apple has indicated that these watches have part numbers ending in "LW/A". Apple Watch models sold before this date, or those with part numbers ending in "LL/A", are generally expected to retain the blood oxygen feature. This distinction is crucial for consumers looking to purchase an Apple Watch with this specific capability.
Status of the Apple Watch Ultra 1
Given that the Apple Watch Ultra 1 was released prior to the January 18, 2024, date when the feature was disabled in new U.S. models, original Ultra 1 watches purchased before this point should have the blood oxygen monitoring capability. However, the situation can be less clear for refurbished or resold Ultra 1 models, as their origin and specific part number would determine whether the software disablement applies. If you are purchasing an Ultra 1, especially from a third-party seller, it is advisable to check the model number to confirm its status regarding the blood oxygen feature.
Availability of the Blood Oxygen Feature on Ultra 1
As established, the Apple Watch Ultra 1 was initially equipped with the blood oxygen sensor and the functionality was active at launch. The recent changes primarily affect newer models (Series 9 and Ultra 2) sold in the US after a specific date due to the patent dispute.
Original Ultra 1 Models
For users who purchased an Apple Watch Ultra 1 when it was initially released or before the January 18, 2024, date for US sales, the blood oxygen feature should be present and functional, provided the Blood Oxygen app is enabled and setup is completed.
Purchasing an Ultra 1 Now
If you are considering purchasing an Apple Watch Ultra 1 currently, particularly in the United States, it's essential to be aware of the potential impact of the patent dispute. While some retailers might still have inventory of Ultra 1 models that were shipped before the disablement took effect, newer stock entering the US market might be subject to the software limitation. Checking the model number (looking for LL/A) is the most reliable way to determine if the blood oxygen feature is expected to be active.
Can the Feature Be Re-enabled?
There have been discussions and reports suggesting that Apple may be able to reintroduce the blood oxygen sensing feature through a future software update if the legal situation changes or a resolution is reached. However, as of now, models with the LW/A designation have the feature disabled via software.
Using the Blood Oxygen App on Supported Apple Watch Models
For those with an Apple Watch Ultra 1 (or other supported models) where the blood oxygen feature is active, using the Blood Oxygen app is straightforward.
Enabling and Taking Measurements
To use the app, you typically need to ensure it is enabled in the Settings on your Apple Watch and potentially in the Apple Watch app on your iPhone. Once enabled, you can open the Blood Oxygen app on your watch and initiate an on-demand measurement. For accurate readings, it's recommended to remain still and ensure the watch has a proper fit on your wrist. The app can also be set up to take periodic background measurements.
Viewing Your Data
All your blood oxygen readings, both on-demand and background, are stored in the Health app on your paired iPhone. You can view your history and trends in the Respiratory section of the Health app under Blood Oxygen.
Table: Apple Watch Models and Blood Oxygen Feature Status (US Market as of Jan 18, 2024)
| Apple Watch Model | Original Blood Oxygen Feature | Status on New Models (US, from Jan 18, 2024) | Status on Models Purchased Before Jan 18, 2024 (US) | Model Number Suffix for Disabled Feature (US) |
|---|---|---|---|---|
| Apple Watch Series 6 | Yes | Not applicable (Older model) | Generally Yes | N/A |
| Apple Watch Series 7 | Yes | Not applicable (Older model) | Generally Yes | N/A |
| Apple Watch Series 8 | Yes | Not applicable (Older model) | Generally Yes | N/A |
| Apple Watch Ultra 1 | Yes | Likely disabled on new stock | Generally Yes | LW/A (for affected new stock) |
| Apple Watch Series 9 | Yes | Disabled via software | Generally Yes | LW/A |
| Apple Watch Ultra 2 | Yes | Disabled via software | Generally Yes | LW/A |
Note: This table summarizes the status for the US market based on information available as of early 2024. Availability may vary in other regions, and the legal situation is subject to change.
Visualizing the Impact: A Relevant Video
To further understand the context of the blood oxygen sensor issue and its impact on Apple Watch availability, the following video provides additional details:
This video discusses the legal situation between Apple and Masimo and its consequences for the availability of the blood oxygen feature on new Apple Watch models.
Frequently Asked Questions
Does every Apple Watch Ultra 1 have the blood oxygen sensor?
Yes, all Apple Watch Ultra 1 models were manufactured with the blood oxygen sensor hardware. However, due to a patent dispute, the software to utilize this sensor has been disabled on new Ultra 1 models sold in the United States since January 18, 2024, indicated by a model number ending in LW/A.
How can I tell if the blood oxygen feature is active on an Apple Watch Ultra 1?
If the Blood Oxygen app is available and functional on the watch, the feature is active. On models where the feature is disabled due to the patent dispute (primarily new US models from January 18, 2024, with LW/A part numbers), the Blood Oxygen app may still appear, but upon opening it, a message will indicate that the feature is not available.
Is the blood oxygen measurement on Apple Watch medically accurate?
Apple explicitly states that the blood oxygen measurements from the Apple Watch are for wellness purposes only and are not intended for medical use. For medical concerns or accurate medical readings, consult with a healthcare professional and medical-grade equipment.
Does the patent dispute affect Apple Watch Ultra 1 models outside of the United States?
The primary impact of the patent dispute and the resulting disablement of the blood oxygen feature has been on Apple Watch models sold in the United States. Availability and functionality in other countries and regions may differ.
Can the blood oxygen feature be re-enabled on affected watches in the future?
Reports suggest that Apple may be able to reintroduce the feature through a software update if the legal situation is resolved. However, there is no guaranteed timeline for this.
References
Last updated May 11, 2025