fNIRS Interactive Viewer

Overview

This web application provides an interactive viewer for fNIRS (functional Near-Infrared Spectroscopy) time-series data. It allows users to visualize HbO (oxyhemoglobin) and HbR (deoxyhemoglobin) concentration changes over time, inspect experimental events, and explore data from different channels.

fNIRS is a non-invasive neuroimaging technique that measures changes in blood oxygenation in the brain, which is tightly coupled to neural activity. This viewer helps researchers and clinicians analyze complex fNIRS datasets through an intuitive interface that supports temporal navigation, channel selection, and event marking.

The application features dynamic visualization capabilities, allowing users to play through recordings in real-time or at adjusted speeds, zoom into specific time windows of interest, and selectively display different signal types. The synchronized display of events alongside hemodynamic responses facilitates the interpretation of brain activation patterns in relation to experimental conditions or tasks.

How to Use

Follow these steps to explore the fNIRS data:

• Channel Selection: Use the checkboxes in the "Channels" list on the sidebar to select or deselect specific fNIRS channels for display. You can use "Select All" and "Deselect All" buttons for convenience.
• Playback Controls:
  • Use the "▶ Play" / "⏸ Pause" button to start or stop the animation of the time-series data.
  • The time slider allows you to manually scrub through the data.
  • Adjust the "Speed" dropdown to change the playback speed of the animation.
• Signal Types: Toggle the "HbO" and "HbR" checkboxes to show or hide the respective signals in the plot.
• Event Navigation: Click on an event in the "Events" list on the sidebar to jump the time marker to the beginning of that event. Events are also visualized as shaded regions on the plot.
• Zoom and Pan: The chart supports zooming (mouse wheel or pinch gesture) and panning (click and drag) for detailed inspection of the data. Use the "Reset Zoom" button to return to the default view.
• Metadata: The "Metadata" section in the sidebar displays key information about the loaded dataset.
• Status Bar: The status bar at the bottom of the plot area shows the current time, active event, and number of selected channels.

Future Directions

Potential enhancements for this application include:

• Implementing more advanced data processing features (e.g., filtering, baseline correction).
• Adding support for different fNIRS data formats or direct data upload.
• Enhancing visualization options, such as topographic maps.
• Improving performance for very large datasets.
• Adding data export capabilities (e.g., exporting the current view as an image or selected data as CSV).
• User accounts and persistent settings.