You may notice the HRV data plotting is trending downward as you are inhaling and upwards as you exhale, creating a discrepancy in the term: real-time.
Q: I'm satisfied with the magnitude of the BPM readings taken by the inner balance/iOS system. It's just that those measurements are displayed a full 5 seconds after they happen. What can I do to see those measurements when they are taken (or within 0.5 or 1 second) instead of having to wait a full 5 seconds to see them?
A: The actual applications (emWave as well as Inner Balance) handle the data in real time with little delay. Coherence calculations happen every 5 seconds after accumulating data from the last 60 seconds. The USB sensors are close to real time. Lightning sensors introduce a slight delay.
But as you noticed, BTLE sensors have a much longer delay. BTLE sensors send data every 2-4 seconds to reduce overhead and power requirements. This is the delay you are seeing. It is true for practically all HR sensors using the standard BTLE protocol. We have not found a satisfactory solution to avoid that issue.
The HeartMath Engineering Team