Studies have found that using a mobile phone for long hours can lower HRV levels.

研究发现，长时间使用手机会导致HRV水平降低。

HRV readings can change depending on if the user is a man or woman, and what their body shape and health conditions are.

HRV读数可根据使用者的两性特征，以及他们的体型和健康状况而变化。

Users wear it on their arm. The device has a sensor that measures hemoglobin oxygen levels and changes to the heart rate called HRV.

用户需要将它戴在手臂上。该设备附带的传感器可测量血红蛋白氧水平和心率变异性（HRV）。