A User-Friendly Approach to NIRS Analysis

 

The nirsLAB package is a versatile software analysis environment developed to support the study of time-varying near-infrared measurements of tissue.  It is ideal for analyzing data collected with NIRx systems, though it can be used to analyze data collected with 3rd-party systems as well.  

 

 


Comprehensive Data Visualization

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Easily visualize and plot your data in every stage of analysis. Users can easily view their data by wavelength and defined activation periods and can easily zoom-in and zoom-out, allowing focus to shift between an entire experiment and particular events of interest.


Analyze What's Important

nirsLAB's Truncate Time Series feature allows the user to simply eliminate non-desired parts of the time series according to the paradigm. 

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Removing periods in which the stimulus paradigm does not take place, such as the beginning of an experiment, the end of an experiment and pauses in the middle of a measurement allow the user to focus on the most critical data.


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NIRS Event-Average Views

 

With options of viewing by different hemodynamic states and event conditions, block experiment results can be easily isolated and reviewed. The image on the right shows results in which left-hand activation is detected in the right motor cortex.


Your Data, Your Way

View you data in a 2D Head Model View, a 3D Head Model View or in 3D Brain Activation Views. Pinpoint a channel, name and change length of events, add new triggers and event types.

 

Filter for band pass, low pass and high pass, removing the frequency bands that are not within the range of interest and eliminating slow drifts on the data as well as fast occuring signals (including the respiratory and the cardiac frequencies). 


SPM at Your Fingertips

Statistical Parametric Mapping has been incorporated into nirsLAB for statistical analysis of hemodynamic-state time series. Several of the currently favored techniques for interpretation of neuroimaging data collected during experiments are available for both Level-1 (within-session and within-subject) and Level-2 (across multiple sessions or subjects) analyses.

The functions currently available include:

Level-1 General linear model (GLM) analysis of fNIRS hemodynamic-state time series, to evaluate the position-dependent relationships between computed data-channel responses and user-specified temporal models. 

Level-1 and Level-2 assessment of the statistical significance of the GLM model-fitting coefficients (t-test, ANOVA), or of user-defined contrasts of two or more models.

 


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Flexibility. In and Out of nirsLAB.

Appreciating that many research groups carry part of the analysis using their own codes, nirsLAB offers the possibility to export the processed data at multiple steps:

  • Raw Preprocessed
  • Raw Filtered
  • Hemodynamic States (oxy- and deoxy-Hb).

The user can also select the exact time frames and channel(s) of interest desired. The data are exported into an intuitive matrix format (text file) and separated with file names describing data type, time frames and channels included.


nirsLAB is Composed of Modules for:

• Importing NIRS measurement data, along with relevant information regarding the measurement that was performed (e.g.,         locations of optical probes [optodes] on the scalp, timing of applied stimuli or experimental tasks, etc.).


• Creating optode-position and event (trigger) files, along wiith toolboxes for editing this information.


• Preprocessing of measurement data using toolboxes that exclude data channels having excessive noise, deleting experimentally irrelevant time intervals, removing artifacts from data and filtering to exclude experimentally irrelevant frequency bands.


• Computing hemodynamic states using wavelength and path length dependent parameter settings.


• Visualizing the time series response of measurement data and computed hemodynamic states within a viewing formats (e.g., stacked, 2D, scalp and cortical).


• Extracting dynamic features from hemodynamic states by use of statistical parametric mapping methods (SPM) and mapping this information to head-space models.

These modules are linked to an automated file manager and a project-specific metadata ledger and provide you with abilities that are both convenient and powerful. 

 

For more information, and access to a free copy of nirsLAB, please contact NIRx directly: info@nirx.net