Masimo's blood-oxygen smartwatch matters beyond the Apple Watch ban — even if you won't buy it

Screenshot of the Masimo Freedom, showing the time, steps, blood oxygen %, pulse rate, and hydration index data on a watch face.
(Image credit: Masimo)

What you need to know

  • Masimo is launching a new Freedom smartwatch and Freedom Band tracker, focused on health tracking.
  • These wearables continuously measure blood oxygen, pulse, heart rate variability, respiration rate, and hydration.
  • Masimo successfully petitioned the ITC to force Apple to sell Apple Watches with blood oxygen disabled, due to an alleged patent infringement. 
  • The Masimo Freedom will launch in 2024 with a revamped version of this SpO2 tech.

Masimo announced its new Freedom watch and Freedom Band last week, both using an enhanced version of the blood oxygen (SpO2) tech Apple allegedly stole for the Series 9. 

As Apple began selling "tweaked" Apple Watches with its SpO2 sensor disabled, Masimo's CEO has taken to the press to push his company's Freedom alternative and call Apple's tech "inaccurate." And while most Apple Watch owners won't buy a Freedom watch, it still represents an important development for health tracking. 

Masimo's president of consumer health, Eugene Goldberg, told The Verge's Victoria Song that the Freedom SpO2 sensor can "account for challenges like motion, low perfusion or bad blood flow, and skin pigmentation," and continuously measures that data where most watches either measure every few minutes or on demand. 

Aside from blood oxygen, these health wearables will track pulse rate, heart rate variability (HRV), respiration rate, and hydration index. More generally, it'll track your steps and activity during workouts, as well as detect if you fall, and also measure your sleep quality. 

The Masimo Freedom Band, which has no display, will send all of this data to your phone app, focusing on people who need accurate health data but no other traditional "smarts." With the Masimo Freedom, Song reports, you'll get a "fairly basic smartwatch" with notifications, timers, and some apps you'll control with the touchscreen or the side touch bar.

The Masimo Freedom will launch sometime later in 2024 for a whopping $999, a price that's clearly suited for people who need continuous health tracking for documented medical conditions — not those who typically buy Apple Watches or the best Android watches

Why the Masimo Freedom matters — and it's nothing to do with Apple

Apple Watch Series 7 SpO2 reading

(Image credit: Apoorva Bhardwaj / Android Central)

Masimo isn't a household name, and the notoriety of challenging Apple in court won't change that. Unless you're someone with documented sleep apnea, you won't spend a grand on a tracker dedicated to blood oxygen data. So, you might ask, why talk about the Freedom at all?

Because most smartwatch brands — not just Apple — have coasted along for years using token SpO2 sensors with documented flaws and no impetus to improve them.

A Nature Journal study found that the "Apple Watch frequently measures SpO2 values outside of the 95–100% range, despite the fact that the watch is worn by healthy participants at rest." Plus, a 2022 lawsuit alleged that the Apple Watch's blood oxygen sensor is "racially biased against people with dark skin tones," as reported by ABC News.

Despite this being an Android-focused site, we're not specifically bashing Apple's accuracy here; what's more relevant is that the Apple Watch is the highest-selling smartwatch in the world, so it gets more attention and medical studies. Across all brands, SpO2 data isn't necessarily reliable, especially for users with darker skin.

Samsung Galaxy Watch 5 Pro sleep tracking results showing range of blood oxygen levels

In our tests, Galaxy Watches tend to show wildly varied SpO2 data for healthy users.  (Image credit: Michael Hicks / Android Central)

When it comes to the best smartwatches with SpO2 monitoring, we chose models with long battery lives capable of continuous data, with Garmin's option for all-day SpO2 readings as our favorite. But only one company — Withings — has FDA approval for its blood oxygen data; most of the rest stress that their data isn't considered medically accurate, with disclaimers about skin tone disrupting their results. 

If brands like Masimo can show medically accurate blood oxygen results are possible in smartwatch form, it will hopefully put pressure on major watch brands to actually improve their results, rather than metaphorically shrug and accept less accurate results for users of color (or users in general) due to the limits of current technology. 

Another lesser-known wearable brand, Rockley, recently showed off a prototype for health sensors that use an IR sensor to read your health data beneath your skin, including blood oxygen — and it's apparently partnered with several major brands. We can hope that smartwatches will leverage this tech to try to meet Masimo on the same level of accuracy. 

Michael L Hicks
Senior Editor, VR/AR and fitness

Michael is Android Central's resident expert on fitness tech and wearables, with an enthusiast's love of VR tech on the side. After years freelancing for Techradar, Wareable, Windows Central, Digital Trends, and other sites on a variety of tech topics, AC has given him the chance to really dive into the topics he's passionate about. He's also a semi-reformed Apple-to-Android user who loves D&D, Star Wars, and Lord of the Rings.


For wearables, Michael has tested dozens of smartwatches from Garmin, Fitbit, Samsung, Apple, COROS, Polar, Amazfit, and other brands, and will always focus on recommending the best product over the best brand. He's also completed marathons like NYC, SF, Marine Corps, Big Sur, and California International — though he's still trying to break that 4-hour barrier.