Dual-Hand PPG Sensing Boosts Wearable Heart Rate Accuracy

The joint research effort, led by Ninenovo, Shanghai Jiao Tong University, and Mianyang Central Hospital, addresses a persistent bottleneck in wearable technology: the assumption that physiological data collected from one side of the body is sufficient for clinical-grade accuracy. By comparing synchronized PPG signals from both hands, the team found that bilateral tracking significantly improves heart rate estimation. Specifically, the mean absolute error dropped from 10.65 bpm to 3.21 bpm, with further refinements reaching 2.59 bpm when signal quality thresholds were maintained.

While the study confirms that bilateral sensing is a powerful tool for heart rate monitoring, it reveals more modest gains for blood pressure estimation, where systolic error improved from 13.81 to 12.36 mmHg. The findings underscore that sensor placement and signal consistency are as vital as data volume. These results, validated across 12 distinct AI model architectures, suggest that future wearable designs may need to account for bilateral signal differences to ensure measurement reliability.