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Applied equipment development and verification of electroencephalogram neurofeedback technology

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Title
脳波ニューロフィードバック技術の応用機器開発と検証
Applied equipment development and verification of electroencephalogram neurofeedback technology
Degree 博士(工学) Dissertation Number 創科博甲第122号 (2023-09-26)
Degree Grantors Yamaguchi University
[kakenhi]15501 grid.268397.1
Abstract
Japan's declining birthrate and aging population are difficult to resolve in the short term, and the working-age population, which refers to the population aged 15 to 65, continues to decline. On the other hand, mental illness patients are increasing in the working age population. The medical side, which is responsible for treatment, is required to improve efficiency by reforming the way doctors work.
Therefore, expectations are placed on psychotherapy performed at home for the purpose of effective treatment of the working-age population. In this study, neurofeedback, which is one of the psychological therapies, was taken up, and applied equipment development and verification were carried out for its implementation at home. In this study, as a preclinical stage, measures were verified based on measurements of general cooperators.
Neurofeedback (NFB) is considered to be one of psychotherapy using electroencephalogram signals, and is a psychotherapy that visualizes one's own electroencephalogram and self-controls the visualized electroencephalogram. It is attracting attention because it is a non-drug therapy and provides neuromodulation. NFB is being investigated for many clinical applications. The target diseases are diverse, including chronic pain, ADHD, depression, and mood disorders. However, we believe that there are four tasks to ensure the effectiveness of this therapy.
Task 1 is overcoming the difficulty of installing electroencephalogram electrodes. NFB is considered to be a therapy that affects the plasticity of the cranial nerves, and is a therapy that actively promotes the development of neural networks, and is expected to be highly effective if the training frequency is high. It is necessary to be able to perform it at home, and it is required that electroencephalogram electrodes can be easily installed. Therefore, we made a prototype of an electroencephalogram headset with bipolar gel electrodes, and as a result of trial verification with children, we were able to confirm the electroencephalogram signals of 30 people aged 5 to 20 years old. Analysis of the recorded electroencephalogram revealed an age-dependent left-brain tendency in β waves, etc., confirming consistency with previous findings.
Task 2 is determining the brain wave derivation part of the NFB training target. For electroencephalography, lead electrodes are usually placed in the scalp, but it is difficult to place the electrodes in the scalp by yourself. There is a need to consider forehead derivation for easy EEG electrode placement at home. There are regional differences in EEG waveforms within the forehead, and it is necessary to select the most appropriate extraction site. For NFB, we explored the optimal site based on the correlation with the top of the head, which is usually the electroencephalogram derivation position. Next, we performed an EEG network analysis at the time of NFB using the EEG derived from the top of the head and the EEG derived from the optimal forehead region, and analyzed the difference in the brain network during NFB due to the difference in the derivation region. For the second task, we explored the optimal site for deriving brain waves from the forehead, and proved that NFB from the brain waves derived from this site works on the same network as NFB from the brain waves derived from the top of the head.
Task 3 is a method of selecting an electroencephalogram frequency band to be derived and self-controlled in NFB therapy (training target electroencephalogram frequency band). In previous studies, the EEG frequencies targeted for NFB therapy are diverse and not standardized. Even for the same disease, various electroencephalogram frequency bands are selected and NFB is performed. A personalized frequency band decision is made according to the patient's pathology and condition. In order to make the frequency band determination method more logical, we thought it necessary to determine the electroencephalogram frequency for therapy from the comparison of the basic rhythms of healthy subjects and patients.
In this study, we created an electroencephalogram basic rhythm evaluation program and collected electroencephalogram basic rhythm data from randomly selected subjects. The electroencephalogram basic rhythm evaluation program consists of 7 stages. Eyes open stage, Eyes closed stage, 0Back stage, Rest1 stage, 2Back stage, Rest2 stage, Healing Picture stage. Changes in brain waves occur due to external stimuli such as eye opening and eye closing, concentration, and relaxation. An electroencephalogram basic rhythm evaluation program was created considering multiple stimuli that affect electroencephalogram dynamics. The usefulness of this program was confirmed as a preliminary examination of the dominant fluctuation region and network analysis by topographic analysis during the execution of the electroencephalogram basic rhythm evaluation program. EEG basic rhythm brain standard program electroencephalogram measurements were carried out for 89 subjects recruited from the general public, and a database was created. Using the forehead optimally measured parts (left and right) obtained in Task 2 as electroencephalogram derivation parts, a significant difference test was performed for each electroencephalogram frequency band Power value and content rate of each stage of the electroencephalogram basic rhythm evaluation program. The α Power value increased 2.52 times when the eyes were closed, and the θ Power value increased 1.67 times during 2 Back compared to 0 Back. We examined the possibility of clinical application by analyzing the correlation between the score of the questionnaire used in clinical diagnosis and the electroencephalogram component.
The questionnaires used were mainly CSI (CENTRAL SENSITIZATION INVENTORY), and POMS2 (Profile of Mood States 2).
Task 4 is NFB scoring. Continuation of psychotherapy requires a score as a reward to be visualized. We compared the two scores, the time ratio score and the amplitude ratio score, analyzed the correlation between the questionnaire used in task 3 and the two scores, and examined the optimal score. In results, the frequency band that correlates better with psychological activity during NFB was suggested SMR.
Some of the psychological scales included the data probably above the general average level, which might have provided hypotheses at the preclinical stage. 4 tasks were conducted to demonstrate the technical requirements and effectiveness evaluation for the practical application of cognitive psychological training NFB, which is expected to be used with high frequency at home for children to working-age adults. The technological requirements and effectiveness evaluation for the practical application of NFB are presented.
This research attempted four tasks and realized the possibility of frequent NFB training at home for patients from children to productive age. As a preclinical stage, it was a study within a range that can be resolved as a stage of policy verification based on the general participant study. In the future, the efficacy of this study will be further evaluated by comparing it with clinical data in the area of mental illness such as depression and developmental disorders, including chronic pain.
In the future, the effectiveness of this study will be further evaluated by comparison with clinical data in the area of chronic pain and other mental illnesses such as depression and developmental disorders.
Creators Oda Kazuyuki
Languages jpn
Resource Type doctoral thesis
File Version Version of Record
Access Rights open access