OH1 / Verity Sense support

[darkzbaron]

Hi there, great work. Any planned support for OH1 sensors?

[JanCBrammer]

Hi @darkzbaron. In order to accurately track heart rate variability the sensor needs to transmit RR intervals. Only electrocardiography (ECG) sensors (i.e., H7, H9, H10) provide RR data. The OH1 is an optical sensor, based on photoplethysmography (PPG). PPG is not suitable for tracking RR intervals.

However, the OH1 does transmit PP intervals. Would have to evaluate if those are accurate enough to compute meaningful HRV. Maybe @marcoalt knows more about the suitability of the OH1 for HRV measurements? Unfortunately I can't get my hands on an OH1 anytime soon to experiment though.

[marcoalt]

Hello Jan, the OH1 reports RR intervals, but similarly to most other optical sensors, they are heavily smoothed and therefore not usable for HRV analysis. Polar moved finally away from this approach, and the latest Verity Sense stopped broadcasting RR intervals and sends only HR (this way at least there is less misusing from unaware users). However, the straps you mention are the only sensors that I would recommend to track RR intervals when there is motion, while at complete rest, the Rhythm24 by Scosche could also be used, as it provides an HRV mode that disables the smoothing (very prone to motion artifacts though). Hope this helps

[JanCBrammer]

Thanks @marcoalt! I suspected that there's quite some PP interval smoothing going on with the OH1, good to have that confirmed. The Scosche device sounds interesting, will check that out.

Also, for future reference, found the table below at https://www.polar.com/en/developers. Seems like it's not up to date anymore though regarding the Verity Sense.

[darkzbaron]

Thanks @marcoalt @JanCBrammer for the info. I really like the form factor of the OH1 that's a shame.

[JackCaster]

@JanCBrammer I stumbled upon your repo and it looks neat! But I am also trying to read HRV-like data from the Polar optical sensor Verity Sense. According to the Polar SDK, the Verity Sense can stream, among others:

• Photoplethysmograpy (PPG) values.
• PP interval (milliseconds) representing cardiac pulse-to-pulse interval extracted from PPG signal.

So, perhaps, we could obtain good-enough HRV (or PRV) measurements directly from the high frequency raw PPG values.

Do you think this is interesting to test?

[JanCBrammer]

perhaps, we could obtain good-enough HRV (or PRV) measurements directly from the high frequency raw PPG values.
Do you think this is interesting to test?

@JackCaster, absolutely, it's worth a shot. I was planning on looking into this, but I haven't bought a Verity Sense yet.

If you're interested in testing this, I'd be super interested in the results.
If the PRV (derived from raw PPG) is good enough I'd consider supporting the Verity Sense.