Apple Watch’s de facto launch party is less than a week away, and there have been a flurry of new reports about the watch as the event — a 1 pm ET presentation on March 9 — draws closer.

If this feels like a repeat … well, it is. (Apple officiallyunveiled Apple Watch at a press event six months ago.)

But Apple Watch is getting a second push because it’s more than just a new product announcement. It’s the lynchpin of Apple’s push into health care, a $3 trillion market in the United States. It’s almost certainly going to change how Americans think about, and use, wearable devices.

And the March 9 event is expected to be Apple’s best chance to share details and pitch the media before the watch is officially released in April.

Apple’s New Plan For Healthcare: The Doctor Will Track You Now

Here’s how Apple Watch could affect health care, featuring screenshots and drawing on the latest leaks.

Apple Watch essentially combines a fitness tracker with a smartwatch

The company’s pitching the device as a breakthrough digital fitness tracker, with a built-in heart rate monitor and accelerometer that sync withApple HealthKit.

An Apple relay will keep your doctor’s fears allayed.

That’s the plan, at least, behind the company’s growing health care strategy: To use the Apple AAPL +0.65% HealthKit platform to collect real-time data from iPhones, the soon-to-be-releasedApple Watch, and other devices — and connect it to hospitals, doctors, and your electronic medical records.

More than a dozen top hospitals already are piloting Apple’s HealthKit software, Christina Farrreported Thursday in an exclusive for Reuters.

This isn’t a surprise. Five months ago, details leaked that Mayo Clinic hadteamed up to test several health care applications for the iPhone, such as a service to alert patients when their Apple apps detected abnormal health results, and help schedule them for follow-up visits.

Also See: Apple and Mayo Clinic’s Partnership Could Be Smart Medicine

And at the September debut for the iPhone 6, Apple officials said that they’d struck partnerships with a number of other top hospitals, like Stanford University Hospital and Duke University.

The two medical centers last year began helping Apple test whether chronically ill patients could use HealthKit to remotely track and manage their symptoms.

A similar trial is now underway at Ochsner Medical Center in New Orleans, where providers are seeing if HealthKit can help several hundred patients control their blood pressure. The patients use sensors and other devices to remotely measure their blood pressure and other clinical indicators, and send the data to Apple phones and tablets through HealthKit.

Apple plans to use its new Watch as part of its strategy to move into the U.S. health care market.

Ochsner also has launched what it’s calling the “O Bar” — the hospital’s version of Apple’s Genius Bar — to help patients pick between different health and fitness apps for their iPhones, and teach them how to use them.

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