Technical variability of the Vivago® wrist-worn accelerometer

Area of Science:

• Biomedical Engineering
• Wearable Technology
• Physical Activity Monitoring

Background:

• Wrist-worn accelerometers are increasingly used to measure physical activity (PA).
• Assessing the technical variability and reliability of these devices under controlled and real-world conditions is crucial for accurate data collection.
• Understanding device performance across different activity intensities is important for public health applications.

Purpose of the Study:

• To evaluate the technical variability of a new wrist-worn accelerometer (Vivago® Wellness).
• To assess device reliability under controlled laboratory conditions using a shaker device.
• To examine accelerometer reliability during various daily physical activities (PAs) of increasing intensity.

Main Methods:

• Experiment 1: 10 accelerometers tested on a shaker device at five frequencies (1.1-10 Hz) for 10 minutes each.
• Experiment 2: 21 participants wore accelerometers during six 10-minute activity periods, ranging from sedentary to vigorous.
• Data analysis focused on inter- and intra-instrument variability using coefficient of variation (CV).

Main Results:

• Controlled conditions showed modest reliability at low frequencies, improving as frequency increased (inter-instrument CV: 2.6-18.3%; intra-instrument CV: 4.1-23.2%).
• Real-world PA testing revealed similar variability patterns, inversely related to intensity.
• CV ranged from 24.2% (inter) and 19.9% (intra) for sedentary activities to 3.7% (inter) and 4.3% (intra) for vigorous PA.

Conclusions:

• Accelerometer reliability is higher during moderate and vigorous physical activity.
• The findings suggest good performance for public health applications recommending these intensity levels.
• The Vivago® Wellness accelerometer demonstrates acceptable technical variability for PA monitoring, particularly during higher intensity activities.