This paper realized a portable brain-computer interface (BCI) system tailored for smart healthcare. Through the decoding of steady-state visual evoked potential (SSVEP), this system can rapidly and accurately identify the intentions of subjects, thereby meeting the practical demands of daily medical scenarios. Firstly, an SSVEP stimulation interface and an electroencephalogram (EEG) signal acquisition software were designed, which enable the system to execute multi-target and multi-task operations while also incorporating data visualization functionality. Secondly, the EEG signals recorded from the occipital region were decomposed into eight sub-frequency bands using filter bank canonical correlation analysis (FBCCA). Subsequently, the similarity between each sub-band signal and the reference signals was computed to achieve efficient SSVEP decoding. Finally, 15 subjects were recruited to participate in the online evaluation of the system. The experimental results indicated that in real-world scenarios, the system achieved an average accuracy of 85.19% in identifying the intentions of the subjects, and an information transfer rate (ITR) of 37.52 bit/min. This system was awarded third prize in the Visual BCI Innovation Application Development competition at the 2024 World Robot Contest, validating its effectiveness. In conclusion, this study has developed a portable, multifunctional SSVEP online decoding system, providing an effective approach for human-computer interaction in smart healthcare.
Brain-Computer Interfaces ; Humans ; Evoked Potentials, Visual/physiology* ; Electroencephalography ; Signal Processing, Computer-Assisted ; Software ; Adult ; Male

Brain-computer interface (BCI) has high application value in the field of healthcare. However, in practical clinical applications, convenience and system performance should be considered in the use of BCI. Wearable BCIs are generally with high convenience, but their performance in real-life scenario needs to be evaluated. This study proposed a wearable steady-state visual evoked potential (SSVEP)-based BCI system equipped with a small-sized electroencephalogram (EEG) collector and a high-performance training-free decoding algorithm. Ten healthy subjects participated in the test of BCI system under simplified experimental preparation. The results showed that the average classification accuracy of this BCI was 94.10% for 40 targets, and there was no significant difference compared to the dataset collected under the laboratory condition. The system achieved a maximum information transfer rate (ITR) of 115.25 bit/min with 8-channel signal and 98.49 bit/min with 4-channel signal, indicating that the 4-channel solution can be used as an option for the few-channel BCI. Overall, this wearable SSVEP-BCI can achieve good performance in real-life scenario, which helps to promote BCI technology in clinical practice.
Brain-Computer Interfaces ; Humans ; Evoked Potentials, Visual/physiology* ; Electroencephalography ; Wearable Electronic Devices ; Algorithms ; Signal Processing, Computer-Assisted ; Adult ; Male

Brain-computer interface (BCI) technology faces structural risks due to a misalignment between its technological maturity and industrialization expectations. This study used the Technology Readiness Level (TRL) framework to assess the status of major BCI paradigms-such as steady-state visual evoked potential (SSVEP), motor imagery, and P300-and found that they predominantly remained at TRL4 to TRL6, with few stable applications reaching TRL9. The analysis identified four interrelated sources of bubble risk: overly broad definitions of BCI, excessive focus on decoding performance, asynchronous translational progress, and imprecise terminology usage. These distortions have contributed to the misallocation of research resources and public misunderstanding. To foster the sustainable development of BCI, this paper advocated the establishment of a standardized TRL evaluation system, clearer terminological boundaries, stronger support for fundamental research, enhanced ethical oversight, and the implementation of inclusive and diversified governance mechanisms.
Brain-Computer Interfaces ; Humans ; Evoked Potentials, Visual ; Electroencephalography ; Event-Related Potentials, P300

In recent years, hybrid brain-computer interfaces (BCIs) have gained significant attention due to their demonstrated advantages in increasing the number of targets and enhancing robustness of the systems. However, Existing studies usually construct BCI systems using intense auditory stimulation and strong central visual stimulation, which lead to poor user experience and indicate a need for improving system comfort. Studies have proved that the use of peripheral visual stimulation and lower intensity of auditory stimulation can effectively boost the user's comfort. Therefore, this study used high-frequency peripheral visual stimulation and 40-dB weak auditory stimulation to elicit steady-state visual evoked potential (SSVEP) and auditory steady-state response (ASSR) signals, building a high-comfort hybrid BCI based on weak audio-visual evoked responses. This system coded 40 targets via 20 high-frequency visual stimulation frequencies and two auditory stimulation frequencies, improving the coding efficiency of BCI systems. Results showed that the hybrid system's averaged classification accuracy was (78.00 ± 12.18) %, and the information transfer rate (ITR) could reached 27.47 bits/min. This study offers new ideas for the design of hybrid BCI paradigm based on imperceptible stimulation.
Brain-Computer Interfaces ; Humans ; Evoked Potentials, Visual/physiology* ; Acoustic Stimulation ; Photic Stimulation ; Electroencephalography ; Evoked Potentials, Auditory/physiology* ; Adult

Coding with high-frequency stimuli could alleviate the visual fatigue of users generated by the brain-computer interface (BCI) based on steady-state visual evoked potential (SSVEP). It would improve the comfort and safety of the system and has promising applications. However, most of the current advanced SSVEP decoding algorithms were compared and verified on low-frequency SSVEP datasets, and their recognition performance on high-frequency SSVEPs was still unknown. To address the aforementioned issue, electroencephalogram (EEG) data from 20 subjects were collected utilizing a high-frequency SSVEP paradigm. Then, the state-of-the-art SSVEP algorithms were compared, including 2 canonical correlation analysis algorithms, 3 task-related component analysis algorithms, and 1 task discriminant component analysis algorithm. The results indicated that they all could effectively decode high-frequency SSVEPs. Besides, there were differences in the classification performance and algorithms' speed under different conditions. This paper provides a basis for the selection of algorithms for high-frequency SSVEP-BCI, demonstrating its potential utility in developing user-friendly BCI.
Humans ; Brain-Computer Interfaces ; Evoked Potentials, Visual ; Algorithms ; Discriminant Analysis ; Electroencephalography

OBJECTIVES: Dysthyroid optic neuropathy (DON) is a class of diseases that makes seriously endanger to the vision of patients with thyroid-associated ophthalmopathy. This study aims to observe the visual function changes in patients with DON, and to evaluate the diagnostic value of indicators diagnosing DON. METHODS: A retrospective study was conducted on 98 eyes of 49 patients with dysthyroid optic neuropathy (DON) who were treated in Xiangya Hospital of Central South University from January 2017 to December 2019. All patients were received the examination of best corrected visual acuity (BCVA), Humphrey visual field, visual evoked potential (VEP), and contrast sensitivity. Ninety-eight eyes were divided into a DON group (45 eyes) and a non-DON group (53 eyes). T-test was used to compare the related indicators between the 2 groups. The sensitivity and specificity of each indicator were analyzed by receiver operating characteristic (ROC) curve. RESULTS: The BCVA and visual field index (VFI) of the DON group were significantly lower than those of the non-DON group (all P<0.05). The mean deviation (MD) and pattern standard deviation (PSD) of the DON group were significantly higher than those of the non-DON group (all P<0.05). The low frequency contrast sensitivity (CSL), medium frequency contrast sensitivity (CSM), and high frequency contrast sensitivity (CSH) of the DON group were significantly lower than those of the non-DON group (all P<0.05), with CSH being particularly prominent. Compared with the non-DON group, at spatial frequencies of 15°, 30°, and 60°, the amplitude of N135 wave was significantly reduced, and the latency of N75 wave, P100 wave, and N135 wave was significantly prolonged in the DON group (all P<0.05); at spatial frequencies of 15° and 30°, the amplitude of P100 wave was significantly reduced in the DON group (P<0.05). The ROC curve analysis results showed that the area under the curve (AUC) of VFI, CSL, CSM, CSH and 15° P100 amplitude diagnosing DON were 0.812, 0.841, 0.880, 0.784, and 0.791, respectively, with CSM possessing the highest sensitivity and specificity. CONCLUSIONS The visual function of patients with DON is decreased. VFI, contrast sensitivity of low, medium, and high frequency, and 15° P100 wave amplitude might be effective indicators for early diagnosis of DON.
Humans ; ROC Curve ; Optic Nerve Diseases/complications* ; Retrospective Studies ; Evoked Potentials, Visual ; Graves Ophthalmopathy

Objective: To analyze the clinical features of children with uridine responsive developmental epileptic encephalopathy 50 (DEE50) caused by CAD gene variants. Methods: A retrospective study was conducted on 6 patients diagnosed with uridine-responsive DEE50 caused by CAD gene variants at Beijing Children's Hospital and Peking University First Hospital from 2018 to 2022. The epileptic seizures, anemia, peripheral blood smear, cranial magnetic resonance imaging (MRI), visual evoked potential (VEP), genotype features and the therapeutic effect of uridine were descriptively analyzed. Results: A total of 6 patients, including 3 boys and 3 girls, aged 3.5(3.2,5.8) years, were enrolled in this study. All patients presented with refractory epilepsy, anemia with anisopoikilocytosis and global developmental delay with regression. The age of epilepsy onset was 8.5 (7.5, 11.0) months, and focal seizures were the most common seizure type (6 cases). Anemia ranged from mild to severe. Four patients had peripheral blood smears prior to uridine administration, showing erythrocytes of variable size and abnormal morphology, and normalized at 6 (2, 8) months after uridine supplementation. Two patients suffered from strabismus, 3 patients had VEP examinations, indicating of suspicious optic nerve involvement, and normal fundus examinations. VEP was re-examined at 1 and 3 months after uridine supplementation, suggesting significant improvement or normalization. Cranial MRI were performed at 5 patients, demonstrating cerebral and cerebellar atrophy. They had cranial MRI re-examined after uridine treatment with a duration of 1.1 (1.0, 1.8) years, indicating significant improvement in brain atrophy. All patients received uridine orally at a dose of 100 mg/(kg·d), the age at initiation of uridine treatment was 1.0 (0.8, 2.5) years, and the duration of treatment was 2.4 (2.2, 3.0) years. Immediate cession of seizures was observed within days to a week after uridine supplementation. Four patients received uridine monotherapy and were seizure free for 7 months, 2.4 years, 2.4 years and 3.0 years respectively. One patient achieved seizure free for 3.0 years after uridine supplementation and had discontinued uridine for 1.5 years. Two patients were supplemented with uridine combined with 1 to 2 anti-seizure medications and had a reduced seizure frequency of 1 to 3 times per year, and they had achieved seizure free for 8 months and 1.4 years respectively. Conclusions: The clinical manifestations of DEE50 caused by CAD gene variants present a triad of refractory epilepsy, anemia with anisopoikilocytosis, and psychomotor retardation with regression, accompanied by suspected optic nerve involvement, all of which respond to uridine treatment. Prompt diagnosis and immediate uridine supplementation could lead to significant clinical improvement.
Male ; Female ; Humans ; Child ; Infant ; Epilepsy/genetics* ; Retrospective Studies ; Drug Resistant Epilepsy ; Uridine ; Evoked Potentials, Visual ; Anemia ; Electroencephalography/adverse effects* ; Neurodegenerative Diseases

Steady-state visual evoked potential (SSVEP) has been widely used in the research of brain-computer interface (BCI) system in recent years. The advantages of SSVEP-BCI system include high classification accuracy, fast information transform rate and strong anti-interference ability. Most of the traditional researches induce SSVEP responses in low and middle frequency bands as control signals. However, SSVEP in this frequency band may cause visual fatigue and even induce epilepsy in subjects. In contrast, high-frequency SSVEP-BCI provides a more comfortable and natural interaction despite its lower amplitude and weaker response. Therefore, it has been widely concerned by researchers in recent years. This paper summarized and analyzed the related research of high-frequency SSVEP-BCI in the past ten years from the aspects of paradigm and algorithm. Finally, the application prospect and development direction of high-frequency SSVEP were discussed and prospected.
Humans ; Brain-Computer Interfaces ; Evoked Potentials, Visual ; Algorithms

High-frequency steady-state asymmetric visual evoked potential (SSaVEP) provides a new paradigm for designing comfortable and practical brain-computer interface (BCI) systems. However, due to the weak amplitude and strong noise of high-frequency signals, it is of great significance to study how to enhance their signal features. In this study, a 30 Hz high-frequency visual stimulus was used, and the peripheral visual field was equally divided into eight annular sectors. Eight kinds of annular sector pairs were selected based on the mapping relationship of visual space onto the primary visual cortex (V1), and three phases (in-phase[0º, 0º], anti-phase [0º, 180º], and anti-phase [180º, 0º]) were designed for each annular sector pair to explore response intensity and signal-to-noise ratio under phase modulation. A total of 8 healthy subjects were recruited in the experiment. The results showed that three annular sector pairs exhibited significant differences in SSaVEP features under phase modulation at 30 Hz high-frequency stimulation. And the spatial feature analysis showed that the two types of features of the annular sector pair in the lower visual field were significantly higher than those in the upper visual field. This study further used the filter bank and ensemble task-related component analysis to calculate the classification accuracy of annular sector pairs under three-phase modulations, and the average accuracy was up to 91.5%, which proved that the phase-modulated SSaVEP features could be used to encode high- frequency SSaVEP. In summary, the results of this study provide new ideas for enhancing the features of high-frequency SSaVEP signals and expanding the instruction set of the traditional steady state visual evoked potential paradigm.
Humans ; Evoked Potentials, Visual ; Brain-Computer Interfaces ; Healthy Volunteers ; Signal-To-Noise Ratio

OBJECTIVES: To investigate the characteristics and objective assessment method of visual field defects caused by optic chiasm and its posterior visual pathway injury. METHODS: Typical cases of visual field defects caused by injuries to the optic chiasm, optic tracts, optic radiations, and visual cortex were selected. Visual field examinations, visual evoked potential (VEP) and multifocal visual evolved potential (mfVEP) measurements, craniocerebral CT/MRI, and retinal optical coherence tomography (OCT) were performed, respectively, and the aforementioned visual electrophysiological and neuroimaging indicators were analyzed comprehensively. RESULTS: The electrophysiological manifestations of visual field defects caused by optic chiasm injuries were bitemporal hemianopsia mfVEP abnormalities. The visual field defects caused by optic tract, optic radiation, and visual cortex injuries were all manifested homonymous hemianopsia mfVEP abnormalities contralateral to the lesion. Mild relative afferent pupil disorder (RAPD) and characteristic optic nerve atrophy were observed in hemianopsia patients with optic tract injuries, but not in patients with optic radiation or visual cortex injuries. Neuroimaging could provide morphological evidence of damages to the optic chiasm and its posterior visual pathway. CONCLUSIONS Visual field defects caused by optic chiasm, optic tract, optic radiation, and visual cortex injuries have their respective characteristics. The combined application of mfVEP and static visual field measurements, in combination with neuroimaging, can maximize the assessment of the location and degree of visual pathway damage, providing an effective scheme for the identification of such injuries.
Humans ; Optic Chiasm/pathology* ; Visual Pathways/pathology* ; Visual Fields ; Evoked Potentials, Visual ; Random Amplified Polymorphic DNA Technique ; Hemianopsia/complications* ; Vision Disorders/pathology* ; Optic Nerve Injuries/diagnostic imaging* ; Brain Injuries, Traumatic/diagnostic imaging*