San Francisco-based startup Rune Labs on Monday said it received clearance from the U.S. Food and Drug Administration to use the Apple Watch to monitor tremors and other common symptoms in patients with Parkinson’s disease.

The Rune Labs software uses motion sensors built into the Apple Watch, which can already be used to detect when a person falls. Rune Labs Chief Executive Brian Pepin said in an interview that Apple Watch data will be combined with data from other sources, including a Medtronic Inc implant that can measure brain signals.

Rune Labs’ goal is for doctors to use the combined data to decide whether and how to fine-tune the patients’ treatment. At present, Pepin said, most doctors have to gather data on a patient’s movements by observing them during a short clinical visit, which is not ideal because Parkinson’s symptoms can vary widely over time.

Using the Apple Watch, Rune Labs’ StrivePD software platform will provide doctors a continuous stream of observations over long stretches, Pepin said.

Pepin added:

When you think about the process of getting someone to their optimal therapy or combination of drugs or devices, or even whether or not a patient might be a good fit for a certain clinical trial, it’s a very hard decision to make when you only have a little context.

The Rune Labs FDA clearance is the first prominent use of software tools that Apple released for measuring movement disorders in 2018.

Last year, a group of scientists at Apple published a study in the journal Science Translational Medicine showing the device was effective at monitoring Parkinson’s symptoms. After contacting Apple about the tools, Pepin said, “it took about eight minutes for the team lead to get back to me and say, ‘Hey, perfect, let’s explore this.'”

Apple has partnered with a range of other companies to use the Apple Watch as a health monitoring device, including a deal with Johnson & Johnson to study whether it can be used to help lower stroke risk.