Part 03 - fNIRS: mobile and high-density applications and multi-modal integration

What are some examples of how NIRS is used today?

Applications of NIRS

NIRx subjects: Infants -> Adults NIRx NIRScaps are comfortable and conforming. Most end-users find it more comfortable than EEG, as it does not involve the use of any scalp abrasion, or heavy, gooey gel. Standard NIRScaps can be worn for several hours with minimal discomfort. Long-term monitoring caps are available upon request, with specialized components to increase comfort and reduce head fatigue.

Flat probes for sensitive subjects The above picture shows a concurrent EEG/NIRS measurement. Use of our flat probes is ideal for subjects with sensitive skin or heads.

Hyperscanning = Multi-subject measurements Multi-subject concurrent measurements have become increasingly popular lately. Peer group, parent-child, and other relationships are effectively quantifiable with the use of our hyperscanning setups.

Video of NIRx Hyperscanning Hyperscanning = Multi-subject measurements Click to watch video! Video of NIRx Hyperscanning

Mobile NIRS - Key The NIRSport is connected to the Surface Tablet via a USB 2.0 connection. The two devices are put into the NIRSport backpack and the backpack is placed on the subject.

Wireless Multi-subject measurements WiFi NIRSport allows multi-subject measurements to be made wirelessly, integrating data from freely-moving subjects in real-world environments. Integrated Data

fNIRS solutions on small animals We offer specialized stereotaxic holders for small rodent measurements.

fNIRS solutions on small animals Freely-moving measurements may also be done on small animals.

fNIRS solutions on large animals - Macaque NIRx offers an integrated hybrid atlas for NIRS studies on rhesus macaque monkeys.

NIRS/EEG – Concurrent Measurements NIRx’s integrated EEG/NIRS solutions are numerous. Here we see integration with the NIRScoutX system and an active electrode EEG setup.

Synchronization of NIRS & EEG Stimulation: Visual Auditory Tactile etc. Response SUBJECT NIRS Measurement USB Digital Interface: LPT (parallel) Port Data Acquisition Card 3rd Party Interface PC Bus Trigger Cable (4 or 8 lines) NIRStar records: NIRS Data Event markers EEG Amp Trigger Splitter (optional)

Visual Study Example – Integrated NIRS/EEG NIRS Source NIRS Detector NIRS Channel

NIRS and EEG Positions EEG electrode NIRS Source NIRS Detector NIRS Channel NIRS Detector

Single-Trial NIRS Response – NIRS/EEG

Real-Time Block Average Display Oz O1 O2 EEG channels

Co-located NIRS-EEG

Brain-Computer Interface with NIRS Streaming

BCI Performance Improvement: EEG+HbO Fazli et al, Neuroimg. 2011

NIRS-EEG Atlas MNI Atlas Subject Atlas

Optical Coupling Solution An optical coupler is used for the active LED sources (NIRScout and NIRSport) and active detectors (NIRSport), so that there is no electrical interference from NIRS while using MRI, TMS, or MEG concurrently with NIRS. Optical probes are used in place of their electrical counterparts for concurrent MRI, TMS, and MEG measurements with NIRS.

Low profile optodes: TMS/fNIRS NIRx offers low-profile optodes for specialized measurements, such as NIRS/TMS applications. Probe height is ~7mm.

fNIRS/fMRI Concurrent Measurement Layout The NIRx system and coupler are located outside the magnet room, with source and detector fibers going to and from the subject respectively. Fibers may be up to 10m in length. Source Current Magnet Room LED-to-Fiber Coupler Detector Current

Portable fNIRS laboratories The NIRSport is lightweight and compact. It is easily setup in any environment, allowing researchers to meet subjects anywhere!

Wearable NIRS Study while biking (Piper et al. Neuroimage 2013) The study exhibited the viability of the portable solution. The subject rode a bicycle while wearing a 16-probe NIRS system.

Portable/Wearable Triggers Subject manual trigger Integrated event presentation earphones Software synchronization 1: Stimulus software USB

Where is NIRS headed in the future?

Optical Tomography in the future The potential for NIRS in the future is immense. A few promising applications on the horizon include: underwater measurements, brain connectivity measurements, and consumer neurofeedback in everyday real-world environments. We see NIRS as a central point for growth in neuroscience in all these areas very soon!

Thanks! ... Questions?