A team of researchers at West Virginia University published a new study aimed at uncovering the black box of how accurate consumer tools are at measuring heart rate and heart rate variability (HRV).

What were the top findings?

Oura’s infrared PPG sensor matched performance with clinical-grade ECG and consistently outperformed other PPG tools relying on green light LEDs or the iPhone camera:

“OURA elicited the lowest MAPE for rMSSD among all PPGs and demonstrated a high degree of concordance with the mECG standard.”*

Oura’s PPG additionally outperformed consumer ECG tools:

“The Oura smart ring (PPG) exhibited better accuracy than all cECGs except for HRV4TR/ECG”

Read the full study in Frontiers in Sports and Active Living.



*MAPE = Mean absolute percent error. Lower MAPE values are ideal because they indicate that Oura is delivering values that are closer to the clinical-grade ECG used for validation.

rMSSD is the most widely used metric for HRV estimation, including within the Oura app.