Noninvasive near‐infrared topography of human brain activity using intensity modulation spectroscopy

Association between longitudinal changes in prefrontal hemodynamic responses and social adaptation in patients with bipolar disorder and major depressive disorder

“…We used a 52-channel NIRS machine (ETG-4000, Hitachi Medical Corporation, Tokyo, Japan) to measure relative changes of [oxyHb] and [deoxyHb] using two wavelengths (695 and 830 nm) of infrared light on the basis of the modified Beer Lambert law (Yamashita et al, 1996). The distance between pairs of emitter and detector probes was set at 3.0 cm, and each measuring area between pairs of emitter and detector probes was defined as a "channel."…”

Correlation of within-individual fluctuation of depressed mood with prefrontal cortex activity during verbal working memory task: optical topography study

“…The system is based on a continuous wave (cw) NIRS technique. [9][10][11] Although other techniques such as time-resolved and frequencydomain techniques [17][18][19] are possibly advantageous for accurate estimation of brain tissue oxygenation and for depth-resolved analysis, [20][21][22] we used the cw NIRS technique because it has proved useful in previous practical studies. [23][24][25][26][27][28] The OT system light sources were cw laser diodes with a wavelength of 695 or 830 nm.…”

“…In our previous study, we used optical topography (OT), which is a noninvasive functional imaging-technique based on NIRS, [9][10][11] to show that a variation in the negative mood state across participants is correlated with their PFC activity for a verbal WM task. 12 OT measures hemodynamic responses in the cerebral cortex under near-natural situations (e.g., sitting position) and allows us to minimize mood modulation due to the experiment itself.…”

Noninvasive imaging of prefrontal activation during attention-demanding tasks performed while walking using a wearable optical topography system

“…Optical topography ͑OT͒ based on an NIRS technique has been developed as a noninvasive technique for mapping ⌬C oxy Ј and ⌬C deoxy Ј with multiple measurement points. [5][6][7][8] In this technique, ⌬C oxy Ј and ⌬C deoxy Ј in the cerebral cortex are measured at multiple points by using alternating optical fiber bundles for irradiation and detection with light at two different wavelengths. OT systems have been used for assessing the cognitive functions of infants [9][10][11][12] and for clinical applications 13,14 because they are noninvasive and less constraining for subjects than other functional imaging techniques, such as functional magnetic resonance imaging and positron emission tomography.…”