From: The role of wearables in spinal posture analysis: a systematic review
Components | |
Accelerometer | Measure proper acceleration |
- I.e. gravitational force (static) and sensor movement (dynamic) | |
- At least one 1D accelerometer | |
Gyroscope | Measure angular velocity |
- At least one 1D gyroscope | |
Magnetometer | Measure all magnetic fields |
- Optional | |
Degrees of Freedom (DoF) | |
9 DoF | 3D accelerometer, 3D gyroscope & 3D magnetometer: |
- Most accurate type of IMU as able to measure proper acceleration, angular velocity and magnetic fields in three axes | |
- Used in: PostureMonitor [34]; Zishi [39]; Xu’s wearable system [33]; Hermanis’ Wearable Sensor Grid [23]; LumoLift [46]; BodyMonitor [22] | |
6 DoF | 3D accelerometer & 3D gyroscope: |
- Less accurate than 9 DoF IMUs as no magnetometer, therefore lower accuracy in determining sensor orientation | |
- Used in: Giansanti’s wearable system [3]; SPoMo [6]; Wong’s wearable system [12]; Miyajima’s wearable system [20] | |
5 DoF | 3D accelerometer & 2D gyroscope: |
- Less accurate than 6 DoF IMUs as gyroscope cannot measure in the third dimension | |
- Used in Lou’s Smart Garment [44] | |
4 DoF | 3D accelerometer & 1D gyroscope: |
- Less accurate than 5 DoF IMUs as gyroscope can only measure in one dimension | |
- Used in DorsaVi’s ViMove [35] |