My Garmin GPS watch has a built-in heart rate monitor. It communicates with a sensor that I strap around my chest. Then while I’m running I can read my heart rate real-time on the watch. It’s a very useful feature.

I don’t use it.

Why not? Well, the strap is annoying to wear. And I don’t know what my target heart rate should be for a given workout anyway. So even if I were to use it and collect all the data, I wouldn’t know what to do with it.

Which is one of the issues that wearable tech is bringing to the forefront, in particular in the medical device field. Here’s what just one new device called the Simband can collect and track:

The Simband … can keep tabs on your daily steps, heart rate, blood pressure, skin temperature, and how much sweat your sweat glands are producing.

I’m not disputing that this can be useful. And there’s nothing revolutionary about what it’s collecting. But this technology promises to disrupt the established medical model. We’re moving from doctors collecting selected information on an as-needed basis to handling floods of information coming in 24/7. It’s a change from assaying some ore samples to trying to filter out a few particles of gold from an onrushing river.

The fast growth in gadgets that can track your vital stats has the attention of the Food and Drug Administration as well. Medical devices are heavily regulated worldwide and must receive FDA approval before they can be sold in the U.S. The key is figuring out where an app crosses the line from providing information to attempting a diagnosis or prescribing treatment, and thus becomes a medical device.

So early in 2015 FDA published guidance that differentiates so-called “general wellness” products from those that pose risk to the user or provide medical advice. (If you’re one of those perverse individuals who likes reading government documents, you can access it here.) But here’s the gist of it: devices that strictly track information you would use for training or general health improvement are not subject to FDA regulation.

So the tracking of heart rate, calories consumed, sleep patterns and the like are fine. And the annoying app CARROT that I mentioned last time can suggest you are gravitationally challenged as long as it doesn’t diagnose you as clinically obese. (Some comfort, eh?)

Behavior is another hurdle to medical wearables becoming commonplace. According to a 2013 study, while one in 10 Americans owned an activity tracker, nearly half had stopped using them after six months. And the main consumers of wearable tech right now are millennials – young, healthy, and who readily embrace new tech. It’s unclear how the older and less affluent – those most likely to have chronic health issues – will embrace the new technology.

Finally, there’s the problem of protecting against those you don’t want seeing your training and/or medical history. Data privacy regulations like HIPAA are all well and good, but (surprise!) not everyone respects them. There are lots of people and organizations out there who would find your personal medical data very useful. Can a phone, watch, or other wearable keep data safe, or can the “cloud” can be made secure? I guess we’ll find out.

And perhaps I will be kicked into this brave new world anyway. Last week after the Dexter-Ann Arbor half marathon, my watch went kaput. So I will be getting a new one which will most likely have a heart rate monitor easier to access and use. And, no doubt, many other features I didn’t know I couldn’t live without. I can’t wait.