1. It's about heart rate. But also it's about the strength of the connection between the spooky pulse and your heart beat. If you turn a test bio feedback on and watch it for 15 mins or so to see if it's continually flashing in time to your heart rate. Mine was losing the calibration to my heart. When this happens, the red light just stays on for sometimes half a minute. So when I stopped using the blue USB cable and connected up my own, it resolved the issue.
2.Those who take a long time will do better doing 15 minute quarter scans. I finally worked up to do half scan in 32 minutes. The next time to get the 2nd half, I failed. So today back to quarter scans to finish the whole.
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