banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
A fast neuronal signal-sensitive continuous-wave near-infrared imaging system
Rent this article for


Image of FIG. 1.
FIG. 1.

Block diagram of the CW NIRI system. MCU is the microcontrol unit, DDS the direct digital synthesis, f1 and f2 the modulation frequencies, LD the laser diode, APD the avalanche photodiode, and DAQ the data acquisition.

Image of FIG. 2.
FIG. 2.

(a) Schematic and (b) photograph of the collimator.

Image of FIG. 3.
FIG. 3.

Detected light vs. OD values of neutral density filters.

Image of FIG. 4.
FIG. 4.

Abridged general view of simulation experiment. The left part presents the composition of the mixed signal, the acquisition, and the off-line analysis before getting the result. The right part shows the results when the baseline of the mixed signal was set at 10 mV. The grey thin line and black thick line represent intensity changes during rest (no virtual stimuli) and task (virtual stimuli included) periods, respectively.

Image of FIG. 5.
FIG. 5.

Time course of changes in hemodynamic parameters during arterial occlusion on a typical subject's arm. The red thin lines represent Δ[HbO2], while the blue thick lines represent Δ[Hb].

Image of FIG. 6.
FIG. 6.

The schematic drawing of the head shows the arrangement of the probe with 2 sources (red circles) and 12 detectors (blue squares). The source-detector distance is 3 cm. The graphs represent Δ[HbO2] and Δ[Hb] traces of the block average responses obtained at 12 locations over the motor cortex for (a) the right-hand and (b) the left-hand finger-tapping measurement. The red thin line and blue thick line represent Δ[HbO2] and Δ[Hb] over the contralateral motor cortex, respectively, while the pink thin line and light blue thick line are Δ[HbO2] and Δ[Hb] for the ipsilateral motor cortex, respectively. The green horizontal bar in each graph indicates the task period.

Image of FIG. 7.
FIG. 7.

Time traces of the averaged optical intensity during right-finger tapping. The blue thick line in all panels represents the averaged intensity changes of all segmented epochs at 785 nm for the channel of maximum contralateral response during the stimulation. The red thin line in panel (a) is the same signal measured at 850 nm. The black thin line in panel (b) is the intensity changes block-averaged with a false stimulation sequence during the rest periods at 785 nm for the same channel. The pink and orange thin lines in panel (c) represent the averaged intensities at 785 nm considering only odd or even stimuli, respectively. The light blue thin line in panel (d) represents the intensity changes during ipsilateral stimulation. The green vertical bars in all panels represent the times when the finger presses the button. The error bars are the standard errors.

Image of FIG. 8.
FIG. 8.

Time-series maps of the dynamic changes of intensity over the motor cortex during right-hand (RH) and left-hand (LH) finger tapping. “Ipsi” and “Contra” indicate the hemispheres ipsilateral and contralateral to the stimulated hand, respectively. Time equal zero is the time when the finger presses the button.


Generic image for table
Table I.

Temporal resolution for different number of channels.

Generic image for table
Table II.

Performance parameters of the CW NIRI system.


Article metrics loading...


Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: A fast neuronal signal-sensitive continuous-wave near-infrared imaging system