Segments a Timed Up-and-Go trial from a trunk/lumbar inertial sensor into its sub-phases (sit-to-stand, walk, turn, turn-to-sit) using the angular velocity: turns appear as large excursions of the vertical-axis (yaw) angular velocity, and the postural sit-to-stand / turn-to-sit transitions as the trunk flexion-axis (pitch) events that bracket the walking (Salarian et al. 2010).
Usage
instrumentedTUG(
angular_velocity,
sampling_rate,
turn_axis = 3L,
transition_axis = 2L,
turn_threshold = NULL,
min_turn_sec = 0.3
)Arguments
- angular_velocity
An n x 3 matrix of trunk angular velocity (rad/s).
- sampling_rate
Sampling rate in Hz.
- turn_axis
Column index of the vertical/yaw axis (default 3).
- transition_axis
Column index of the trunk flexion/pitch axis (default 2).
- turn_threshold
Angular-velocity threshold (rad/s) that marks a turn;
NULLuses0.15 * max(abs(yaw)).- min_turn_sec
Minimum turn duration in seconds (default 0.3).
Value
An itug_report object with total_duration, a turns data frame
(start, end, duration, peak_velocity, angle_deg), the
stand_up_time/sit_down_time, and a phases data frame.