Apple's Blood Oxygen Sensor: A Feature in Decline
For a few years, the blood oxygen sensor on Apple Watch models was a prominent health feature, touted for its ability to provide users with insights into their respiratory and overall cardiovascular well-being. However, in late 2026, Apple quietly removed this functionality from its newest Series 9 and Ultra 2 models in the United States. This decision, which has sparked considerable curiosity and debate, stems from a complex legal battle over patent infringement.
The Root of the Issue: Masimo's Patents
The primary reason behind Apple's discontinuation of the blood oxygen sensor in the U.S. is a patent dispute with medical technology company Masimo. Masimo, a pioneer in noninvasive patient monitoring, holds several patents related to blood oxygen sensing technology, including the specific way light is used to measure oxygen saturation levels in the blood.
Masimo sued Apple in 2020, alleging that the Apple Watch's blood oxygen sensor infringed upon its patented technology. A lengthy legal process ensued, culminating in the U.S. International Trade Commission (ITC) ruling in favor of Masimo in January 2026. The ITC found that Apple's infringement was indeed established and issued a limited exclusion order, which essentially blocked the importation of Apple Watches with the infringing blood oxygen sensor into the United States.
Apple's Response and Temporary Workarounds
Following the ITC ruling, Apple explored various avenues to continue offering its smartwatch line in the U.S. Initially, Apple attempted to appeal the ruling, but this did not immediately resolve the issue. In the interim, to comply with the import ban, Apple made the decision to remove the blood oxygen measurement feature from the Series 9 and Ultra 2 models specifically for sale in the United States. This meant that while the hardware for the sensor was still present, the software that powered the blood oxygen readings was disabled.
It's important to note that this discontinuation primarily affected new sales of the Series 9 and Ultra 2 in the U.S. Existing Apple Watches with the blood oxygen sensor, and those sold in other countries where the patent dispute did not apply, continued to function as before. Apple also worked on software updates for international markets and potentially for future models that would not infringe on Masimo's patents.
What Does Blood Oxygen Measurement Do?
Before delving further into the discontinuation, it's helpful to understand what the blood oxygen sensor on the Apple Watch actually does. The feature, typically called "Blood Oxygen" or "SpO2," uses infrared light and red LEDs on the underside of the watch to measure the oxygen saturation level in your blood. This measurement, expressed as a percentage, indicates how much oxygen your red blood cells are carrying.
- Normal Range: For most healthy individuals, blood oxygen levels typically range from 95% to 100%.
- Health Insights: Significant drops in blood oxygen levels can be indicative of various respiratory or cardiovascular issues, such as sleep apnea, asthma, chronic obstructive pulmonary disease (COPD), or even poor lung function due to conditions like pneumonia.
- On-Demand and Background Readings: The Apple Watch allowed users to take on-demand blood oxygen readings or set it up for background measurements, especially during sleep.
Why is this Feature Important?
The ability to track blood oxygen is valuable because it can serve as an early warning system for potential health problems. For individuals with pre-existing conditions, it offers a way to monitor their status and detect any concerning changes. For others, it can provide peace of mind or prompt them to seek medical attention if an anomaly is detected. The feature was particularly promoted for its utility in detecting potential signs of sleep apnea, a common sleep disorder.
The Future of Blood Oxygen on Apple Watch
While the blood oxygen sensor has been removed from the latest U.S. models, it doesn't necessarily mean the end of this feature for all Apple Watch users or for all time. The situation is fluid and dependent on ongoing legal proceedings and Apple's ability to engineer around existing patents.
Apple has stated its commitment to providing its customers with innovative health features. It's plausible that Apple is actively working on:
- Developing alternative sensing technologies: The company may be designing a blood oxygen sensor that uses a different methodology, thereby avoiding Masimo's patents.
- Reaching a licensing agreement: It's also possible that Apple and Masimo could reach a licensing agreement, allowing Apple to use Masimo's patented technology for a fee.
- Legal appeals: Apple may continue to pursue legal challenges to overturn the ITC ruling.
The U.S. Court of Appeals for the Federal Circuit is a key venue for such patent disputes. The outcome of any further appeals will significantly influence whether the blood oxygen sensor can eventually return to Apple Watches sold in the United States.
What This Means for Consumers
For consumers in the United States who purchased an Apple Watch Series 9 or Ultra 2 after the feature was removed, the blood oxygen sensor will not function. This could be a disappointment for those who relied on or were interested in this health metric. However, for many users, other features of the Apple Watch, such as ECG, fall detection, and general fitness tracking, remain unaffected.
If you are in the United States and specifically need a smartwatch with a blood oxygen sensor, you would need to look at older Apple Watch models (prior to Series 9 and Ultra 2 with this specific patent issue) or consider smartwatches from other manufacturers that do not face these patent restrictions.
"The discontinuation of the blood oxygen sensor on new Apple Watch models in the U.S. is a stark reminder of how complex the intersection of technology, health, and intellectual property can be. It highlights the importance of patent law in driving innovation, and conversely, how it can sometimes create hurdles for established features."
Frequently Asked Questions (FAQ)
Why did Apple stop selling Series 9 and Ultra 2 with blood oxygen in the U.S.?
Apple discontinued the blood oxygen sensor feature in the U.S. on its Series 9 and Ultra 2 models due to a patent infringement ruling by the U.S. International Trade Commission (ITC) in favor of Masimo. The ITC ruled that Apple's blood oxygen sensor technology infringed on Masimo's patents, leading to an import ban on affected devices.
Will my existing Apple Watch with blood oxygen still work?
Yes, if you already own an Apple Watch model that includes the blood oxygen sensor (e.g., Series 6, 7, 8, or prior Ultra models), your existing device will continue to function normally and the blood oxygen feature will remain available. The discontinuation primarily affects new sales of the Series 9 and Ultra 2 in the United States.
How does the Apple Watch measure blood oxygen?
The Apple Watch uses advanced sensors on the back crystal to shine infrared and red light onto your wrist. Photodiodes measure the amount of light that is reflected back. This measurement is then used to calculate the color of your blood, which is an indicator of how much oxygen it carries. This process is known as photoplethysmography (PPG).
Can I get blood oxygen readings outside of the U.S. on Series 9 and Ultra 2?
Yes, the blood oxygen sensor feature remains available on Apple Watch Series 9 and Ultra 2 models sold in countries outside of the United States. The ITC ruling and the subsequent import ban were specific to the U.S. market.
