The Functional Infrared Brain Scan

Precision Diagnosis

fNIRS

The functional infrared brain scan

(Functional Near-Infrared Spectroscopy, fNIRS)

DH, Medical Device Division, Listing Number：252296

The functional infrared brain scan measures oxygen levels in the brain when performing a mental task. The oxygen level can help to identify whether an individual is in a disease range (e.g., ADHD) or a healthy range. This waveform also shows how the frontal and temporal lobes function during a mental task and reflects real-life difficulties.

The fNIRS device used in this clinic has been listed with the Hong Kong Department of Health under the Medical Device Administrative Control System.

Professional and technical

fNIRS

The functional infrared brain scan is known as functional near-infrared spectroscopy (fNIRS).
Our clinic uses a 48-channel fNIRS device with wavelengths 780 and 850 nm to measure the oxy-hemoglobin concentration.
The source-detector pairs examined forty-eight regions of the prefrontal cortex.
High and low pass filters ranged from 0.005 to 0.1 Hz, with the threshold of signal noise at 30 dB set to remove motion artifact and machine drift of physical contamination.
The baseline measurement referred to the average hemodynamic responses from 5 to 0 seconds before each cognitive task.
The resulting data were collected 8.138 times per second
Finally, the mean HbO2 was estimated to be the average of the changes in HbO2 over the entire time frame of each cognitive task to determine whether it is in a healthy range or a disease range (e.g., ADHD range).

Academic paper

publications

The infrared brain scan was validated in previous studies where Dr. Ho is a co-author, and the detailed performance of the system was also mentioned in the following academic papers:

Hong M, Dong SY, McIntyre RS, Chiang SK, Ho R. fNIRS Classification of Adults with ADHD Enhanced by Feature Selection. IEEE Trans Neural Syst Rehabil Eng. 2024 Dec 24;PP. doi: 10.1109/TNSRE.2024.3522121. Epub ahead of print. PMID: 40030659.

Husain SF, Chiang SK, Vasu AA, Goh CP, McIntyre RS, Tang TB, Tran BX, Dang THT, Nguyen TT, Ho RC, Ho CS. Functional Near-Infrared Spectroscopy of English-Speaking Adults With Attention-Deficit/Hyperactivity Disorder During a Verbal Fluency Task. J Atten Disord. 2023 Nov;27(13):1448-1459. doi: 10.1177/10870547231180111. Epub 2023 Jun 21. PMID: 37341192.

Chhoa KH, Chiang SK, Ong KY, Yong CK, Ng BZ, Othman SZ, McIntyre RS, Choi J, Cha J, Ho RC, Chee KY. Changes in Cerebral Hemodynamic Among Patients With Schizophrenia or Bipolar Disorder Receiving Electroconvulsive Therapy: A Task-Related Functional Near-Infrared Spectroscopy Study. J ECT. 2025 Jan 24. doi: 10.1097/YCT.0000000000001110. Epub ahead of print. PMID: 39853313.

Tran BX, Nguyen TT, Boyer L, Fond G, Auquier P, Nguyen HSA, Tran HTN, Nguyen HM, Choi J, Le HT, Latkin CA, Nathan KI, Husain SF, McIntyre RS, Ho CSH, Zhang MWB, Ho RCM. Differentiating people with schizophrenia from healthy controls in a developing Country: An evaluation of portable functional near infrared spectroscopy (fNIRS) as an adjunct diagnostic tool. Front Psychiatry. 2023 Jan 26;14:1061284. doi: 10.3389/fpsyt.2023.1061284. PMID: 36778640; PMCID: PMC9910791.

Tran BX, Nguyen TT, Nguyen HSA, Boyer L, Auquier P, Fond G, Tran HTN, Nguyen HM, Choi J, Latkin CA, Ho CSH, Husain SF, McIntyre RS, Zhang MWB, Ho RCM. Utility of portable functional near-infrared spectroscopy (fNIRS) in patients with bipolar and unipolar disorders: A comparison with healthy controls. J Affect Disord. 2023 Feb 15;323:581-591. doi: 10.1016/j.jad.2022.11.091. Epub 2022 Dec 11. PMID: 36516913.

Disclaimer:
At THMC Mental Health & Innovation Centre, the adoption of innovative technologies, including functionalized near-infrared spectroscopy (fNIRS), eye tracking, and computerized neurocognitive testing as assessment tools for Attention Deficit Hyperactivity Disorder (ADHD) is subject to the following terms:

1. Research Basis: The technologies outlined herein are utilized based on findings from the research article published in Psychiatry and Clinical Neurosciences in 2025. These findings demonstrate the efficacy of combining three objective markers—fNIRS, eye tracking, and computerized tests—along with seven objective parameters to distinguish adults with ADHD from healthy controls, achieving a sensitivity of 80.28% and specificity of 84.51%.
2. No Guarantee of Results are Positive for ADHD: While these technologies have shown promising results in research settings, their effectiveness may vary in individual cases. The adoption of these methods does not guarantee a diagnosis of ADHD or any other condition. The assessment tools may yield normal findings despite the person complains of inattention or hyperactivity.
3. Clinical Judgment: The interpretation of results from these technologies must be conducted by qualified healthcare professionals. These tools are intended to complement, not replace, clinical assessments and professional judgment.
4. Limitations and Risks: Users of these technologies should be aware of potential limitations, including but not limited to variability in test performance and the influence of external factors on results. Concerns about risks associated with testing and interpretation should be discussed with a healthcare provider.
5. Liability: THMC Mental Health & Innovation Centre shall not be liable for any direct or indirect consequences arising from the use of these technologies in ADHD diagnosis. Users assume all risks associated with the interpretation and use of data derived from these assessments.
6. Continued Research: Ongoing research is necessary to further validate these technologies and their application in clinical settings. Users are encouraged to stay informed about updates in research findings and clinical practices.

By utilizing these technologies, you acknowledge and accept the terms of this legal disclaimer.

Precision Diagnosis

fNIRS

The functional infrared brain scan

Professional and technical

fNIRS

Academic paper

publications

香港中環干諾道中13-14號

1601, Euro Trade Centre, 13-14 Connaught Road Central, Hong Kong

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