nparACT

nparACT computes non-parametric measures from actigraphy recordings to quantify sleep–wake patterns and circadian activity characteristics.

Key Features:

• Non-Parametric Measures: nparACT computes Interdaily Stability (IS), Intradaily Variability (IV), and Relative Amplitude (RA) from actigraphy data.
• Interdaily Stability (IS): IS assesses the consistency of activity levels across different days.
• Intradaily Variability (IV): IV measures fragmentation within a single day by quantifying fluctuations in activity levels.
• Relative Amplitude (RA): RA quantifies the difference between peak and trough activity levels to reflect circadian rhythm robustness.
• Activity Periods (M10): Calculates start times and mean activity for the ten consecutive hours with maximal activity (M10).
• Activity Periods (L5): Determines start times and mean activity for the five consecutive hours with minimal activity (L5).
• Customizable L-value (Lflex): Computes an L-value (least activity value) over a user-defined time span termed Lflex.
• Data Handling: Supports analysis of single and multiple actigraphy files.
• Visualization: Provides plotting functions for computed parameters and activity patterns.
• Implementation: Implemented as an R package.

Scientific Applications:

• Sleep–wake pattern monitoring: Quantifies sleep–wake patterns from actigraphy recordings for observational studies.
• Intervention studies: Evaluates effects of experimental or clinical interventions on circadian rhythms and daily activity stability.
• Chronobiology and sleep medicine: Supports research in chronobiology, sleep medicine, and related fields focused on temporal behavior patterns.

Methodology:

Computes non-parametric measures (IS, IV, RA) from movement-sensor actigraphy recordings, calculates M10 and L5 start times and mean activity, computes Lflex over user-defined spans, supports single/multiple file input, and produces plots of the computed parameters.