Heart-rate sensor - does it use height/weight/gender etc to produce continuous heart rate values?

[nickmay]

I am involved in conducting research using the continuous heart-rate monitor function of wristbands. We are registered as a research project with Fitbit and have access to the granular heart-rate data over the web-api.

We are currently using the Charge 3. We plan to purchase several hundred.

We are interested only in monitoring heart-rates, over short periods of time. We are NOT interested in energy use, calorie consumption. Vox2,  or any other feature.

Questions:

[If answers to these are referenced in your documentation I would be very grateful for a link. If these questions are better directed to a different person or forum, please let me know]

1: We want to enter generic height (i.e. 166.8 cm) and weight (i.e. 59.6 KG)  values and date of birth [e.g. 22] for test-subjects as a privacy measure. [Date of birth varies at most by a year among participants]  

Are these values used in the measurement of heart-rate? [We are not actually interested in the absolute value of the heart-rate, we are interested in the change in rate over time.]

2: Does the "sex/gender" setting affect the measurement of heart rate?

3: Does the heart-rate monitor [specifically] "learn" or "remember" anything about the person wearing it that changes the values it produces if subsequently used by someone else?

E.g. if I put it on my wrist for 10 minutes, then put it on friend's wrist, will the fact it has been on my wrist have an affect on the values it gives for the friend's heart-rate? Or will it measure both directly and as accurately as it can, given a few minutes to settle down.

4: Activities mode: we use this to give us a timestamp in our heart-rate data. Does the particular activity selected change the way the heart-rate monitor works?

E.g. does the "run" activity make the sensor more sensitive to higher heart-rates at the cost of reduced sensitivity to lower heart-rates?

Typically the tasks our test-subjects are asked to do involve lower heart-rates. Is there a particular "activity" that we should select in this case?

Thank you very much for your assistance.

[JohnFitbit · Accepted solution]

Hi @nickmay,

The heart rate sensors do not rely on a user's personal information to display heart rate readings. You can read about how our devices read heart rate data here.

A person's personal information (age, weight, sex) is only used to determine calorie burn or BMR, which you've stated, is data that you wouldn't be interested in. How our devices read heart rate is standard across all devices. The type of activity or person's personal information has no effect on how HR is detected.

If you are planning to pass the device off to different users under a single account, you may want to give the device a few seconds to adjust to the new user's heart rate reading after a transfer. Detection isn't automatic and may take a few seconds to adjust to the "new arm". The devices don't learn or remember anything about a user's heart rate other than what is manually set for heart rate zones for the user in the Fitbit app.

[nickmay]

Thank you very much indeed - this is exactly what we had hoped.

regards Nick