Safety and Product Information - Q: Pure Pulse usage

[BiasedMOSFET]

On the Fitbit and Safety Product Warning Page it states the follow:

"PurePulse products have a heart rate tracking feature that may pose risks to users with certain health conditions.

Consult your doctor prior to use if you:

• have a medical or heart condition;
• are taking any photosensitive medicine;
• have epilepsy or are sensitive to flashing lights;
• have reduced circulation or bruise easily; or
• have tendonitis, carpal tunnel syndrome, or other musculoskeletal disorders."

After talking with my Doctor we couldn't quite figure out why this warning exists for carpal tunnel syndrome. He suggested that I should just make sure I don't wear the strap too tightly and there should be no risks.

Why does this warning exist? It is my understanding that PurePulse works by measuring the reflection of the LEDs off the user's skin to determine the rate of the heartbeat. Does the warning exist because of the LED itself? Possibly the heat/energy coming out of the pulsing LEDs? 

As an engineer and a person with carpal tunnel syndrome, I would like to know why this warning exists. Any help would be greatly appreciated. What actual risks does the PurePulse pose to users with any of the problems above?

Moderator edit: Updated subject for clarity.

[YojanaFitbit]

Hi @BiasedMOSFET welcome to the Community Forums. It's great to have you here.

Thanks for posting your inquiry here, you have an excellent question. This information has been posted to all users having any of this conditions to seek for instructions on how to use the Fitbit bands. Your doctor's recommendation is pretty effective. But in some cases not all users take the time to read the Wear and Care instructions. 

About the PurePulse LED lights, this is used to illuminate the quantity of blood passing by your wrist. This quantity is reflected and captured in the panel located between the lights and this gives you the bpm in your Fitbit. The PurePulse LED lights are on the visible spectrum, similar to the lights in your home or office, this means that the lights have very low power so they won't harm your skin. And all Fitbit devices are compliant with FCC regulations.

Let me now if you have more questions about this.

[BiasedMOSFET]

---

@YojanaFitbit wrote:

About the PurePulse LED lights, this is used to illuminate the quantity of blood passing by your wrist. This quantity is reflected and captured in the panel located between the lights and this gives you the bpm in your Fitbit. The PurePulse LED lights are on the visible spectrum, similar to the lights in your home or office, this means that the lights have very low power so they won't harm your skin. And all Fitbit devices are compliant with FCC regulations.

---

Hi @YojanaFitbit, thank you for the quick response. I figured the LEDs weren't the problem but couldn't think of anything else. If the warning is just about the band usage, is that because users might wear it tighter than non-PurePulse devices in order to ensure the PurePulse works?

[LZeeW]

@BiasedMOSFET   I just want to chime in to mention that Fitbit recommends one position on your wrist for day-to-day wear (one finger from the bony part of your wrist).  When exercising, the position is three finger widths away.  Users are tempted to wear it tighter, too, when exercising.  Like you, I suspect it is all about the band tightness.