Apple Watch users are losing a popular health app after court's ruling in patent case

Starting Thursday, the ability to measure blood oxygen levels will no longer be available on newly purchased Apple Watch Series 9 and Watch Ultra 2 models.

According to the tech giant, customers who purchase the watches in the U.S. will still be able to see Apple's Blood Oxygen app on their devices, but when tapped, users will get a message saying the feature is no longer available.

Apple decided to drop the health feature after losing a patent case brought by the medical technology company Masimo, which alleged that Apple infringed on its patent for a blood oxygen sensor that can read someone's pulse. Apple has repeatedly denied the allegation.

The U.S. International Trade Commission found in October that some Apple Watches had violated Masimo's patents, and issued a ban on the import of watches that included the technology.

Apple has continued to appeal the case and said they believe the U.S. Court of Appeals for the Federal Circuit should reverse the trade commission's decision.

"We strongly disagree with the USITC decision and resulting orders," an Apple spokesperson said in a statement on Thursday.

On Wednesday, the appeals court decided to reinstate the feature ban after temporarily granting Apple's request to pause it in December.

Instead of banning the watches outright, the court granted Apple permission to continue selling the watch as long as changes were made to remove the technology at the center of the patent fight.

In a statement, Masimo founder and CEO Joe Kiani wrote that the court's decision to reinstate the feature ban "affirms that even the largest and most powerful companies must respect the intellectual rights of American inventors and must deal with the consequences when they are caught infringing others' patents."

Apple said "there is no impact to Apple Watch units previously purchased that include the Blood Oxygen feature."

Last fiscal year, Apple made almost $40 billion in its so-called wearables category, and the company's watches are the top seller in the product line.