Measure oxy-, deoxy-, and total hemoglobin concentration changes, optionally absolute concentrations and tissue saturation index in both brain and muscle tissue.


The OxyMon Mk III is a user-friendly and very flexible near infrared spectroscopy system. The system monitors a subject’s local tissue oxygenation non-invasively by utilising the technique of near infrared spectroscopy. 

  • Highlights

    Stable, versatile and highly sensitive
    Possible to measure on both brain and muscle tissue
    Numerous configurations, from 1 to 100+ channels
    Fast data collection at 50 Hz as standard - up to 250 Hz possible, for any amount of channels
    No need to screen against ambient light
    Unlimited data storage
    The light detector cannot be damaged by ambient light
    Raw data (optical densities) easily accessible
    Up to 4 wavelengths per channel

  • The technique

    Near infrared spectroscopy, (NIRS), the technique on which the OxyMon is based, relies mainly on two characteristics of human tissue. Firstly, the relative transparency of tissue for light in the NIR range, and secondly on the oxygenation dependent light absorbance of hemoglobin.

  • Technical Specifications

    Continuous wave near infrared spectroscopy using modified lambert-beer law.
    Changes in oxy-deoxyhemoglobin and optionally regional tissue saturation index (TSI) using spatially resolved spectroscopy.
    Data analysis software
    Operating system
    Windows 7, 8, 10
    Light source(s)
    Temperature stabilized pulsed laser sources (class I, IEC-60825-1, safety of lasers)
    Optode holders
    Multiple distances for muscle or head possible, multichannel generally customer specific.
    Optode distance
    Depending on application. Frontal head up to 6 cm possible with arterial pulsation still visible. For fnirs 3-4cm is recommended.
    Operating temperature: ~10-27 °c. Both source and detector are temperature stabilized.
    0-5750 m.
    Weight: 7 to 8 kg, wxdxh: 37x30x9 cm
    Between 1 and 112.
    External inputs
    Optional are 8 additional analog inputs at 50 Hz (250 Hz optional), ± 4 volt.
    Real-time, unlimited data storage.
    Temperature stabilized and cooled avalanche photo diodes with ambient light protection.
    Standard nominal 765 and 855 nm, other wavelengths are possible.
    We can deliver NMR compatible fibers for compatibility with MRI. EEG/ECG does not interfere the optical signal.
    Auto sensing: 110-240 v, approx. 40 Watt.
    AD input/output box
    AD board
    Parellelsync cable
    Oxysoft 3D extenstion.
    NIRS + EEG
    Oxymon + TMSI EEG package (16 channels or more).
    NIRS + EMG
    OxyMon + TMSI EMG package (2 channels or more).
    NIRS + Eyetracking
    OxyMon + Tobii eyetracker.

fNIRS system

The OxyMon is one of the most versatile and fastest NIRS systems on the market. We offer a wide range of fibers, holders and fit-for-purpose solutions to support you as best as possible and to adept each system to your specific needs. We deliver a set-up enabling you to measure up to 100+ brain channels simultaneously with real time visualization. Our systems have been used for over a decade in hundreds of publications.

  • Compatibility

    The system is compatible with e.g. TMS, tDCS, tACS, TCD. For any other modilities, please contact us for additional information.

  • Configurations

    We deliver the OxyMon from a 1 channel system up to 100+ channels in various standard configurations. For every customer we offer a fit-for-purpose solution. Please contact us so we can discuss what configuration is best for you.

  • Multi Modal System

    The OxyMon is a multi modal system. We offer various methods to synchronize with other modalities such as EEG, fMRI and EMG.

NIRS Software

All of our devices are bundled with Oxysoft. Oxysoft is our dedicated software application used to collect, store, view, and analyse all necessary data from the OxyMon. This user-friendly software is developed by Artinis and highly customisable to individual requirements. Oxysoft provides in real-time the calculation of oxy-, deoxy-, total hemoglobine and TSI. 

fNIRS Applications

The OxyMon has been used in almost all thinkable fields of research like study the aging brain, the brain at high altitude, functional testing and for brain computer interfacing (BCI). The system can be combined with other techniques such as EEG, TCD or MRI. We even offer fully integrated NIRS/EEG packages


    Electroencephalography (EEG) and near-infrared spectroscopy (NIRS) both offer information about brain function, complementing each other in their ability to resolve information about both the spatial and temporal characteristics of neural activity. The electrical potentials in brain tissue can be measured by EEG with high temperal resolution. NIRS measures the changes in oxygenation and blood volume, which also reflect neural activity and provide spatial information. Our NIRS equipment does not interfere with EEG signals. It is possible to combine head caps for EEG and our NIRS devices. We offer various methods to synchronize with other modalities, including EEG. We also offer combined NIRS-EEG package deals. Contact us for more information.

    - Multimodal integration of fNIRS, fMRI and EEG neuroimaging.
    [Muthalib M, Anwar AR, Perrey S, Dat M, Galka A, Wolff S, Heute U, Deuschl G, Raethjen J, Muthuraman M. Clin Neurophysiol. 2013 May 3. pii: S1388-2457(13)00260-5.]
    - Electrocortical and Hemodynamic Changes within the Brain during Incremental Bicycle Exercise in Normoxia and Hypoxia—A Combined EEG/NIRS Study.
    [Abeln V, Schneider S, Knicker A, Schiffer T, Hollmann W, Strüder HK. Journal of Sports Science 3 (2015) 105-116]
    - Combined EEG-fNIRS decoding of motor attempt and imagery for brain switch control: an offline study in patients with tetraplegia.
    [Blokland Y, Spyrou L, Thijssen D, Eijsvogels T, Colier W, Floor-Westerdijk M, Vlek R, Bruhn J, Farquhar J. DOI 10.1109/TNSRE.2013.2292995, IEEE Transactions on Neural Systems and Rehabilitation Engineering]


    Near-infrared spectroscopy (NIRS) can also be combined with transcranial Doppler (TCD). This can specifically be interesting if one wants to investigate the relation between oxygen supply and oxygen metabolism in the brain.

    - Does cerebral oxygen delivery limit incremental exercise performance?
    [Subudhi AW, Olin JT, Dimmen AC, Polaner DM, Kayser B, Roach RC. J Appl Physiol. 2011 Dec;111(6):1727-34]
    - Effects of acetazolamide and dexamethasone on cerebral hemodynamics in hypoxia.
    [Subudhi AW, Dimmen AC, Julian CG, Wilson MJ, Panerai RB, Roach RC. J Appl Physiol. 2011 May;110(5):1219-25.]
    - Reproducibility of cerebral blood volume measurements by near infrared spectroscopy in 16 healthy elderly subjects.
    [Claassen JA, Colier WN, Jansen RW. Physiol. Meas. 2006: 27 255-264.]


    NIRS can be used in conjunction with to fMRI to study hemodynamics in the brain. The advantages of NIRS over MRI are:

    • High temporal resolution.
    • Excellent intrinsic sensitivity to hemoglobin - fMRI can only monitor [HHb] changes (the BOLD effect), where NIRS also measure [O2Hb] changes.
    • Measurements can be applied to a variety of tasks.
    • Easily adapted to incorporate other techniques (EEG, fMRI).
    • Economical, portable, scalable.
    • No contra-indication to ferrous implants.
    • No patient claustrophobia.
    • Fewer motion artifacts.

    A statistical parametric mapping (SPM) tool is also available for combining NIRS signals with MRI data.
    - NIRS-SPM: statistical parametric mapping for near-infrared spectroscopy
    [Ye JC, Tak S, Jan KE, Jung J, Jang J. Neuroimage 2009; 44(2): 428-47]
    With special NMR-compatible fibers the Oxymon can be used in the MRI. The fiber length can be up to 10 m.
    - Comparison of causality analysis on simultaneously measured fMRI and NIRS signals during motor tasks.
    [Anwar AR, Muthalib M, Perrey S, Galka A, Granert O, Wolff S, Deuschl G, Raethjen J, Heute U, Muthuraman M. Conf Proc IEEE Eng Med Biol Soc. 2013;2013:2628-31]
    - Simultaneous measurements of cerebral oxygenation changes during brain activation by near-infrared spectroscopy and functional magnetic resonance imaging in healthy young and elderly subjects.
    [Mehagnoul-Schipper DJ, van der Kallen B, Colier WNJM, van der Sluijs MC, van Erning LJTO, Thijssen H, Oeseburg B, Hoefnagels W, Jansen R.Human Brain Mapping 2002. 16: 14-23.]
    - Quantitative analysis of hemodynamic and metabolic changes in subcortical vascular dementia using simultaneous near-infrared spectroscopy and fMRI measurements.
    [Tak S, Yoon SJ, Jang J, Yoo K, Jeong Y, Ye JC. Neuroimage. 2011 Mar 1;55(1):176-84.]

  • Surgery

    NIRS monitoring of the brain during surgery provides information about cerebral perfusion and oxygenation. Two examples are given below.

    NIRS Surgery.

    NIRS and transcranial Doppler on the middle cerebral artery are recorded simultaneously in a patient during an elective cardiac arrest in order to test a newly placed pacemaker (figure on the left). The pacemaker was placed because of cardiac arrhythmia. After the cardiac arrest the pacemaker stimulates the heart to start again. Optodes were placed on the frontal side of the head, 5.5 cm apart. The NIRS measurement shows a decrease in the hemoglobin concentrations and the total blood volume during the cardiac arrest. After the cardiac arrest, the hemoglobin concentrations recover. The transcranial Doppler measurement shows a similar decrease during the cardiac arrest, and then recovery of hemoglobin concentrations.

    NIRS measurement from a pig's head taken with clamped arteries, shows decreased oxygenated hemoglobin concentrations and similar increases in deoxygenated hemoglobin concentration. First the left artery, then the right and then both arteries were clamped (figure on the right). Post clamping recovery and overshoot are visible.

  • Physiology

    Using venous and arterial occlusions it is possible to measure parameters as muscle oxygen consumption, blood volume and blood flow. Combined with other modalities you can also measure blood volume and flow in the brain.

    - Forearm blood flow and oxygen consumption in patients with bilateral repetitive strain injury measured by near-infrared spectroscopy.
    [Brunnekreef JJ, Oosterhof J, Thijssen D, Colier WNJM, van Uden CJT. Clin Physiol Funct Imaging 2006; 26: 178–184]
    Near-infrared assessments of skeletal muscle oxidative capacity in persons with spinal cord injury.
    [Erickson ML, Ryan TE, Young HJ, McCully KK. Eur J Appl Physiol. 2013 May 24.] - Muscle oxygen consumption by NIRS and mobility in multiple sclerosis patients.
    [Malagoni AM, Felisatti M, Lamberti N, Basaglia N, Manfredini R, Salvi F, Zamboni P, Manfredini F. BMC Neurol. 2013 May 29;13(1):52.] - In vivo quantitative near-infrared spectroscopy in skeletal muscle during incremental isometric handgrip exercise.
    [Van Beekvelt MCP, van Engelen BG, Wevers RA, and Colier WNJM. Clin Physiol Funct Imaging. 2002 22(3): 210-217.]

  • Main references

    Ferreri L, Bigand E, Bard P, Bugaiska A. The influence of music on prefrontal cortex during episodic encoding and retrieval of verbal information: a multichannel fNIRS study. Behavioural Neurology, 11 May 2015. Herff C, Heger D, Fortmann O, Hennrich J, Putze F, Schultz T. Mental workload during n-back task-quantified in the prefrontal cortex using fNIRS. Front Hum Neurosci. 2014 Jan 16;7:935. doi: 10.3389/fnhum.2013.00935. Kennedy DO, Haskell CF. Cerebral blood flow and behavioural effects of caffeine in habitual and non-habitual consumers of caffeine: a near infrared spectroscopy study. Biol Psychol. 2011 Mar;86(3):298-306. Mehagnoul-Schipper, DJ, Vloet LCM, Colier WN, Hoefnagels WH, Verheught FW, Jansen, RW. Cerebral oxygenation responses to standing in elderly patients with predominantly diastolic dysfunction. Reproducibility of orthostatic changes in cerebral oxygenation in healthy 70 years and older. Clin Phys and Funct Imaging. 2003; 23-2: 92-97. Minati L, Jones CL, Gray MA, Medford N, Harrison NA, Critchley HD. Emotional modulation of visual cortex activity: a functional near-infrared spectroscopy study. Neuroreport 2009 Oct 7;20(15):1344-50. Rupp T, Esteve F, Bouzat P, Lundby C, Perrey S, Levy P, Robach P, Verges S. Cerebral hemodynamic and ventilatory responses to hypoxia, hypercapnia, and hypocapnia during 5 days at 4,350 m. J Cereb Blood Flow Metab. 2013 Sep 25. doi: 10.1038/jcbfm.2013.167. Song S, Kim D, Jang DP, Lee J, Lee H, Lee KM, Kim IY. Low-frequency oscillations in cerebrovascular and cardiovascular hemodynamics: their interrelationships and the effect of age. Microvasc Res. 2015 Aug 12. Spyrou L, Blokland Y, Farquhar J, Bruhn J. Singular spectrum analysis as a preprocessing filtering step for fNIRS brain computer interfaces. Proceedings of EURASIP 2014. Subudhi AW, Lorenz MC, Fulco CS, Roach RC. Cerebrovascular responses to incremental exercise during hypobaric hypoxia: effect of oxygenation on maximal performance. Am J Physiol Heart Circ Physiol. 2008; 294(1):H164-71. Tak S, Yoon SJ, Jang J, Yoo K, Jeong Y, Ye JC. Quantitative analysis of hemodynamic and metabolic changes in subcortical vascular dementia using simultaneous near-infrared spectroscopy and fMRI measurements. Neuroimage. 2011 Mar 1;55(1):176-84. Tan Q, Zhang M, Wang Y, Zhang M, Wang Y, Xin Q, Wang B and Li Z. Frequency-specific functional connectivity revealed by wavelet-based coherence analysis in elderly subjects with cerebral infarction using NIRS method. Med. Phys. 42, 5391 (2015) Van Beek AH, Lagro J, Olde-Rikkert MG, Zhang R, Claassen JA. Oscillations in cerebral blood flow and cortical oxygenation in Alzheimer's disease. Neurobiol Aging. 2011 Jan 3.

  • fNIRS

    NIRS measurements of the visual cortex during visual stimulation show the activation of the visual cortex by changes in the oxy– and deoxy-hemoglobin ([O2Hb] and [HHb]) concentration. The figures below show an example of NIRS measurement during visual cortex stimulation.

    An example of a NIRS measurement during visual cortex stimulation. Adapted from Colier, W.N.J.M; et al. Vision Research (2001) 41:97-102.
    Visual Cortex Stimulation

    The curves trace the left and right hemisphere oxygenation changes in response to right and left hemi-field visual stimuli. The stimulus (10 s) was a green and white reversing (8 Hz) hemi-field checkerboard. Both [O2Hb] and [HHb] (in μM) are tim-averaged over six right and left hemi-field stimuli. Left and right panels refer to the left and right visual cortex areas, respectively.
    Visual stimulation provoked an increase in [O2Hb] accompanied by a smaller decrease in [HHb]. The reported decrease in [HHb] shows the ability of fNIRS to detect the localized changes: left hemi-field stimuli induce a decrease in [HHb] in the right visual area and no decrease in the left visual area and vice versa.
    Functional NIRS (fNIRS) can be done using single channels or multiple-channel NIRS devices. Multiple channels allow 3D brain-mapping to be performed.

    Prefrontal cortex activation during story encoding/retrieval: a multi-channel functional near-infrared spectroscopy study.
    [Basso Moro S, Cutini S, Ursini ML, Ferrari M, Quaresima V. Front Hum Neurosci. 2013 Dec 31;7:925. doi: 10.3389/fnhum.2013.00925. eCollection 2013]
    Activity to Lapses in Attention.
    [Derosière G, Billot M, Ward ET, Perrey S. Adaptations of Motor NeuralStructures Cereb Cortex. 2013 Aug 19. PubMed PMID: 23960205.]
    A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood.
    [Dodd FL, Kennedy DO, Riby LM, Haskell-Ramsay CF. Psychopharmacology (Berl). 2015]
    The influence of music on prefrontal cortex during episodic encoding and retrieval of verbal information: a multichannel fNIRS study.
    [Ferreri L, Bigand E, Bard P, Bugaiska A. Behavioural Neurology, 11 May 2015.]

  • Tissue saturation measurement

    Our NIRS devices can use multiple distances between the receiver and a number of transmitters. With this it is possible to calculate absolute values of oxygenation by means of spatially resolved spectroscopy. This technique is used in real time and is of special interest e.g. in monitoring brain oxygenation during surgery or muscle oxygenation during exercise. The option comes standard with the PortaMon and PortaLite and is optional for the Oxymon.

    Cerebral blood flow and oxygenation at maximal exercise: the effect of clamping carbon dioxide.
    [Olin JT, Dimmen AC, Subudhi AW, Roach RC. Respir Physiol Neurobiol. 2011 Jan 31;175(1):176-80.]
    Effect of endurance training on performance and muscle reoxygenation rate during repeated-sprint running.
    [Buchheit M, Ufland P. Eur J Appl Physiol. 2010 Sep 25.]

  • Rehabilition

    NIRS is an ideal non-invasive tool to be used in rehabilitation in several ways. For example effect of training on muscle perfusion after disease, or brain functionality.

    Combined EEG-fNIRS decoding of motor attempt and imagery for brain switch control: an offline study in patients with tetraplegia.
    [Blokland Y, Spyrou L, Thijssen D, Eijsvogels T, Colier W, Floor-Westerdijk M, Vlek R, Bruhn J, Farquhar J. DOI 10.1109/TNSRE.2013.2292995, IEEE Transactions on Neural Systems and Rehabilitation Engineering.]
    Skeletal muscle metabolic recovery following submaximal exercise in chronic heart failure is limited more by O(2) delivery than O(2) utilization.
    [Kemps HM, Prompers JJ, Wessels B, De Vries WR, Zonderland ML, Thijssen EJ, Nicolay K, Schep G, Doevendans PA. Clin Sci (Lond). 2009 Oct 26;118(3):203-10.]
    Changes in oxygenated hemoglobin link freezing of gait to frontal activation in patients with Parkinson disease: an fNIRS study of transient motor-cognitive failures.
    [Maidan I, Bernad-Elazari H, Gazit E, Giladi N, Hausdorff JM, Mirelman A. J Neurol. 2015 Jan 31.]
    Effect of aerobic interval training on erythrocyte rheological and hemodynamic functions in heart failure patients with anemia.
    [Wang JS, Fu TC, Lien HY, Wang CH, Hsu CC, Wu WC, Chien YW, Cherng WJ. Int J Cardiol. 2012 Nov 27.]

  • Mitochondrial Function

    Users of our equipment developed methods to estimate mitochondrial function using non invasive NIRS.

    Influence of exercise training with resveratrol supplementation on skeletal muscle mitochondrial capacity.
    [Polley KR, Jenkins N, O’Connor P, McCully K. Applied Physiology, Nutrition, and Metabolism, 10.1139/apnm-2015-0370]
    Noninvasive evaluation of skeletal muscle mitochondrial capacity with near-infrared spectroscopy: correcting for blood volume changes.
    [Ryan TE, Erickson ML, Brizendine JT, Young HJ, McCully KK. J Appl Physiol. 2012 Jul;113(2):175-83]

  • Neurofeedback/BCI

    NIRS can be used to build a real-time NIRS-based brain-computer interface. Our device can be connected to a buffer from the Matlab toolbox ‘FieldTrip’, which makes it possible to do online data analysis and manipulation in Matlab. As an example, it is possible to play Brain Snake. The hemodynamic response in the motor cortex to finger tapping was used to play the computer game ‘Snake’. Two NIRS channels with transmitter-receiver distances of 4cm and 1.5 cm were placed over the motor cortex. A few seconds after starting the finger tapping, a response was visible at the 4 cm channel. The signal of the superficial 1.5 cm channel was subtracted from the 4 cm channel in order to cancel out the Mayer waves. The Mayer waves mask the task related changes in the cortex. The difference signal was used to control the computer game. A few seconds after starting finger tapping the oxyhemoglobin concentration increased. When the signal amplitude increased above a certain threshold, the snake would make a right turn. This simple setup demonstrates that a computer can be controlled using NIRS-detected signals from the brain.

    Continuous affective states recognition using functional near infrared spectroscopy.
    [Heger D, Herff C, Putze F, Mutter R, Schultz T. Brain-Computer Interfaces 13-5-14. DOI:10.1080/2326263X.2014.912884]
    Combined EEG-fNIRS decoding of motor attempt and imagery for brain switch control: an offline study in patients with tetraplegia.
    [Blokland Y, Spyrou L, Thijssen D, Eijsvogels T, Colier W, Floor-Westerdijk M, Vlek R, Bruhn J, Farquhar J. DOI 10.1109/TNSRE.2013.2292995, IEEE Transactions on Neural Systems and Rehabilitation Engineering]

  • Geriatrics & pediatrics

    NIRS is often used on sensitive subjects such as elderly and children, because of the relative robust signal during moderate movement.

    Reproducibility of cerebral blood volume measurements by near infrared spectroscopy in 16 healthy elderly subjects.
    [Claassen JA, Colier WN, Jansen RW. Physiol. Meas. 2006: 27 255-264.]
    Assessment of dynamic cerebral autoregulation and cerebrovascular CO2 reactivity in aging by measurements of cerebral blood flow and cortical oxygenation.
    [Oudegeest-Sander MH, van Beek AH, Abbink K, Olde Rikkert MG, Hopman MT, Claassen JA. Exp Physiol. 2013 Dec 20.]
    Changes in cerebral oxygenation and hemodynamics during cranial ultrasound in preterm infants.
    [Van Alfen-van der Velden AA, Claessen VP, Hopman JC, Klaessens JH, Sengers RC, Liem KD. Brain Dev. 2008 Oct 4;31(6):427-34.]


fNIRS set-up with the OxyMon

As for the device, the fibers and the holders are separate items -
together we will find the best configuration that fits your needs


OxyMon research package

What’s in the box?

 The OxyMon
 Fibers of your choice
 Headcap or holders of your choice
 License key
 Oxysoft, data analysis software
 Stickers and bandages
 Dark cloth or bandana
 User Guide
 Support in setting up your research

Extend your research:
Full fNIRS set-up: The Oxymon car
3D Software
NIRS research accessory or add-on devices

Extend your research

Artinis NIRS products are intended to be used for research applications only. Our products are not sold as Medical Device as defined in EU directive 93/42/EEC. Our products are not designed or intended to be used for diagnosis or treatment of disease.