Table 1.
Product specification comparison.
| SenseWear | CT1/RT3 | AMP331 | GT3X/GT1M | StepWatch | activPAL | IDEEA | |
|---|---|---|---|---|---|---|---|
| Size (mm) | 88.4 × 56.4 × 24.1 | 71 × 56 × 28 | 71.3 × 24 × 37.5 | 38 × 37 × 18 | 75 × 50 × 20 | 53 × 35 × 7 | 70 × 54 × 17 |
| Weight (g) | 82.2 | 71.5 | 50 | 27 | 38 | 20 | 59 |
| Accelerometer type | na | Piezoelectric | na | na | na | piezoresistive | piezoelectric |
| Number of accelerometer | 1 | 1 | 2 | 1 | 1 | 1 | 5 |
| Number of accelerometer axis | 2 | 1/3 | 1 uni-axis and 1 dual-axis | 3/1 | 2 | 1 | 2 |
| Sensor placement | Upper arm | Waist | Ankle | Waist or wrist | Ankle | Thigh | Chest, thigh, feet |
| Sampling rate | 32 Hz | 0.017–1 Hz | na | 30 Hz (12 bit) | 128 Hz | 10 Hz (8 bit) | 32 Hz |
| Sensitivity range | 2 g | na | na | 0.05–2.5 g | na | 2 g | 5 g |
| Battery type | 1.5 V AAA × 1 | 1.5V AAA × 1 | na | 3.7 V Lithium ion/Lithium Polymer | 750 mAh Lithium | 3 V li-polymer rechargeable | 1 1.5 V AA |
| Battery life | 3 days (continuous) | 30 days | na | 20 days | na | 7–10 days | 60 hrs |
| Data transmission | RF/USB | USB (docking tation) | 916 MHz RF (USB wireless adapter) | USB | USB (docking station) | USB (ducking station) | USB |
| Data storage capacity | na | 3 hours to 21 days (dependant on data resolution and collection) | na | 16 MB (or 40 days) | 2 months | na | 7 days |
| Reported parameters | EE estimation, activity duration, sleep duration | Activity intensity, EE, MET | Steps, cadence, walking speed, stride length, distance, EE | Activity counts, steps, MET, activity intensity level | Steps gait characteristics | Sedentary and upright time, steps, stepping time, cadence, sit-to-stand activities, MET, PAL, kCal | Activity types, gait types, EE |