Nirscout

A multi-channel, continuous wave, fNIRS instrument (NIRScout; NIRx Medical Technologies LLC; Minneapolis, MN, United States) was used to monitor hemodynamic activity during the task and at rest. The sampling rate was 7.81 Hz. Probes were arranged according to a 10/20 electroencephalogram system with some adjustments to ensure that each emitter was 3 cm from its corresponding detector. Two 3 × 5 optode probe sets (eight emitters and seven detectors, with a 3-cm optode separation) were used. Each set consisted of 22 measurement channels that were placed over the right frontoparietal regions of the brain. The center of the middle probe set row was placed at C4 according to the 10/20 international system (Jurcak et al., 2007 (link); Pan et al., 2017 (link); Figure 1).

This dataset consists of mental arithmetic tasks performed by 29 healthy participants. The experiment consisted, for each participant, of 30 epochs (divided into three sessions) of each mental arithmetic and baseline task. Each epoch displayed the subtraction for 2 s, had a 10 s task period with a fixation cross, and a 15–17 s rest period also with a fixation cross. The data was recorded with a NIRScout from NIRx Medical Technologies, with a sampling rate of 10 Hz. It is composed of 14 sources and 16 detectors on the PFC, resulting in 36 channels at 760 nm and 36 channels at 850 nm, with a source-detector distance of 30 mm. More details can be found in Shin et al. (2016b (link)). This dataset has been used for classification between baseline task and mental arithmetic.

This experiment adopts the multi-channel, continuous-wave desktop fNIRS system (NIRScout, NIRx Medical Technologies LLC, Glen Head, NY, USA) with a sampling frequency of 3.91 Hz, equipped with 16 detectors and 16 sources with dual wavelengths of 780 and 830 nm. The distance between the detectors and sources was set to 30 mm, producing 51 channels covering the prefrontal and motor cortices of the brain (Figure 1). To wear the fNIRS head cap, the experimenter located the Cz point, which is the intersection between the line connecting the nasion and the inion and the line connecting the external auditory meatus [27 (link)]. After the cap was fitted, the source and detector probes were fixed using a snap button in a plastic holder to ensure adequate contact with the participant’s scalp. The brain was scanned continuously for 5 min during the resting state before and after the exercise.

The brain metabolism evaluation will be performed using another optical imaging system (NIRScout, NIRx Medical Technologies LLC, Glen Head, NY, USA) consisting of 16 light source fibers and 16 detector fibers, resulting in a 48-channel recording of cortical changes in oxygenated, deoxygenated and total hemoglobin. For the measurements of the present study the optodes will be tightly placed on the skull with the use of a holder cap with the interoptode distance set at 30 mm, covering the bilateral motor and premotor cortex. Patients will walk on the treadmill at a speed of 0.2 km/h assisted by personnel and with partial body weight support if needed, performing four short tasks (30 s of walking) alternated by rest periods (30 s) [73 (link)]. Data will be analyzed for possible selective changes of cerebral perfusion by specific software (NIRSlab). For each patient will be calculated the area under the curve of oxygenated, deoxygenated and total hemoglobin for each channel and hemisphere (media of the area under curve of each one of the 24 channels of selected hemisphere). Moreover, the data will also be analyzed with the software NIRS-SPM to draw a map of activation of the selected brain areas during the test and to perform a t test statistical comparison within subjects and between treatments, as well as other possible correlations with clinical or laboratory parameters.

This dataset consists of n-back tasks performed by 26 healthy participants. The experiment consisted, for each participant, of nine epochs (divided into three sessions) of each 0-back, 2-back, and 3-back. Each epoch consisted of 2 s of instructions, 40 s of task and 20 s of rest period. A random digit was given every 2 s displayed for 0.5 s and the targets appeared with a 30% chance. The data was recorded with a NIRScout from NIRx Medical Technologies, with wavelengths of 760 and 850 nm and a sampling rate of 10 Hz. It is composed of 16 sources and 16 detectors on the PFC, resulting in 36 channels of HbO and 36 channels of HbR, with a source-detector distance of 30 mm. More details can be found in Shin et al. (2018 (link)). This dataset has been used for classification between 0-back, 2-back, and 3-back.

The fNIRS probe was designed to cover the main brain regions irrigated by the carotid arteries with 14 sources (each source had two different wavelengths, 760 and 850 nm) and 30 detectors arranged in a head cap (Figure 1a). This geometric configuration allowed 48 different source–detector pairs (channels) with a 3 cm separation between sources and detectors. All fNIRS measurements were performed with a commercial system (NIRScout, NIRx Medical Technologies, Germany) with an acquisition rate of 8.2 Hz.
The experimental protocol was carried out during the patient’s regular visit to the clinic. After a 60 s period of rest, subjects were required to perform up to seven trials of voluntary breath-holding (BH) for a target duration of 10 s each. Each trial was followed by a resting period of 30 s (Figure 1b).

We measured cortical neural activation using a 42 channel NIRScout (NIRx Medical Technologies) fNIRS device with a sampling rate of 7.81Hz. A total of 32 (sources = 16, detectors = 16) fNIRS optodes were distributed over both hemispheres. We positioned the optodes over standard 10 to 20 system locations using individually sized caps (Brain Products) selected based on head circumference. The 10 to 20 locations were spatially adjusted across all cap sizes to maintain consistent coverage of our regions of interest despite changes in head size across participants [33 (link)]. Consistent 3-cm channel distance was achieved using plastic supports between each source/detector pair that constituted a recording channel.
Our montage was designed to optimize coverage of brain structures in the frontal, temporal, and parietal lobes. Fig 2 shows the channel locations as well as the functional localization clusters (described later).