sit2standpy.TransitionQuantifier

class sit2standpy.TransitionQuantifier

Quantification of a sit-to-stand transition.

Methods

quantify(times, fs[, raw_acc, mag_acc_f, …]) Compute quantitative values from the provided signals
sparc(x, fs[, padlevel, fc, amp_th]) SPectral ARC length metric for quantifying smoothness
quantify(times, fs, raw_acc=None, mag_acc_f=None, mag_acc_r=None, v_vel=None, v_pos=None)

Compute quantitative values from the provided signals

Parameters:
times : tuple

Tuple of the start and end timestamps for the transition

mag_acc_f : {None, numpy.ndarray}, optional

Filtered acceleration magnitude during the transition.

mag_acc_r : {None, numpy.ndarray}, optional

Reconstructed acceleration magnitude during the transition.

v_vel : {None, numpy.ndarray}, optional

Vertical velocity during the transition.

v_pos : {None, numpy.ndarray}, optional

Vertical position during the transition.

Returns:
transition : Transition

Transition object containing metrics quantifying the transition.

static sparc(x, fs, padlevel=4, fc=10.0, amp_th=0.05)

SPectral ARC length metric for quantifying smoothness

Parameters:
x : numpy.ndarray

Array containing the data to be analyzed for smoothness

fs : float

Sampling frequency

padlevel : int, optional

Indicates the amount of zero-padding to be done to the movement data for estimating the spectral arc length. Default is 4.

fc : float, optional

The max cutoff frequency for calculating the spectral arc length metric. Default is 10.0

amp_th : float, optional

The amplitude threshold to be used for determining the cut off frequency up to which the spectral arc length is to be estimated. Default is 0.05

Returns:
sal : float

The spectral arc length estimate of the given data’s smoothness

(f, Mf) : (numpy.ndarray, numpy.ndarray)

The frequency and the magnitude spectrum of the input data. This spectral is from 0 to the Nyquist frequency

(f_sel, Mf_sel) : (numpy.ndarray, numpy.ndarray)

The portion of the spectrum that is selected for calculating the spectral arc length

References

S. Balasubramanian, A. Melendez-Calderon, A. Roby-Brami, E. Burdet. “On the analysis of movement smoothness.” Journal of NeuroEngineering and Rehabilitation. 2015.