Detecting Glaucoma With a Portable Brain-Computer Interface for Objective Assessment of Visual Function Loss

Abstract

The current assessment of visual field loss in diseases such as glaucoma is affected by the subjectivity of patient responses and the lack of portability of standard perimeters.OBJECTIVE To describe the development and initial validation of a portable brain-computer interface (BCI) for objectively assessing visual function loss. DESIGN, SETTING, AND PARTICIPANTSThis case-control study involved 62 eyes of 33 patients with glaucoma and 30 eyes of 17 healthy participants. Glaucoma was diagnosed based on a masked grading of optic disc stereophotographs. All participants underwent testing with a BCI device and standard automated perimetry (SAP) within 3 months. The BCI device integrates wearable, wireless, dry electroencephalogram and electrooculogram systems and a cellphone-based head-mounted display to enable the detection of multifocal steady state visual-evoked potentials associated with visual field stimulation. The performances of global and sectoral multifocal steady state visual-evoked potentials metrics to discriminate glaucomatous from healthy eyes were compared with global and sectoral SAP parameters. The repeatability of the BCI device measurements was assessed by collecting results of repeated testing in 20 eyes of 10 participants with glaucoma for 3 sessions of measurements separated by weekly intervals. MAIN OUTCOMES AND MEASURESReceiver operating characteristic curves summarizing diagnostic accuracy. Intraclass correlation coefficients and coefficients of variation for assessing repeatability. RESULTS Among the 33 participants with glaucoma, 19 (58%) were white, 12 (36%) were black, and 2 (6%) were Asian, while among the 17 participants with healthy eyes, 9 (53%) were white, 8 (47%) were black, and none were Asian. The receiver operating characteristic curve area for the global BCI multifocal steady state visual-evoked potentials parameter was 0.92 (95% CI, 0.86-0.96), which was larger than for SAP mean deviation (area under the curve, 0.81; 95% CI, 0.72-0.90), SAP mean sensitivity (area under the curve, 0.80; 95% CI, 0.69-0.88; P = .03), and SAP pattern standard deviation (area under the curve, 0.77; 95% CI, 0.66-0.87; P = .01). No statistically significant differences were seen for the sectoral measurements between the BCI and SAP. Intraclass coefficients for global and sectoral parameters ranged from 0.74 to 0.92, and mean coefficients of variation ranged from 3.03% to 7.45%. CONCLUSIONS AND RELEVANCEThe BCI device may be useful for assessing the electrical brain responses associated with visual field stimulation. The device discriminated eyes with glaucomatous neuropathy from healthy eyes in a clinically based setting. Further studies should investigate the feasibility of the BCI device for home-based testing as well as for detecting visual function loss over time.

<p>Comparison of head-mounted perimeter (imo^&reg;) and Humphrey Field Analyzer</p>

“…In recent years, more practical devices using virtual reality glasses have been developed. However, these devices show similarities to the SAP grayscale, and clinical data have yet to be collected 11–13. imo ® (CREWT Medical Systems, Tokyo, Japan), the device used in this study, is the only head-mounted perimeter currently in use in clinical practice 14.…”

“…However, these devices show similarities to the SAP grayscale, and clinical data have yet to be collected. 11 – 13 imo ® (CREWT Medical Systems, Tokyo, Japan), the device used in this study, is the only head-mounted perimeter currently in use in clinical practice. 14 Owing to the head-mounted design, examinations do not require a dark room or a large space to install equipment.…”

Cost-efficient and Custom Electrode-holder Assembly Infrastructure for EEG Recordings

“…First, the sensor-holder ring can be fabricated with different specifications to organize either homogeneous/heterogeneous sensors or sensors and stimulators on the same headset, e.g., comparing EEG electrodes made by different materials at very adjacent sites [1,5,35,40], facilitating a simultaneous EEG and functional near-infrared spectroscopy (fNIR) recording over the brain regions of interest [31], and monitoring EEG activity while applying transcranial alternating current (TAC) stimulation [41]. In addition, the assembly structure is surely capable of being retrofitted to a head-mounted display system (e.g., AR/VR goggle), worn on the head for stand-alone application [16,19,42]. In contrast, a headset with an immobile design to an end user may make the above applications difficult to implement.…”

“…Owing to its interesting advantages of price, usability, and mobility, a considerable number of recent studies has emerged highlighting the aforementioned advantages to encourage the study of EEG correlates of brain states and functions in multidisciplinary domains, such as preliminary perception (e.g., visual/auditory responses [4,5,6]), cognition capacity (e.g., attention relocation [7,8], face recognition [1], and memory processing [9,10]), and psychological reaction (e.g., affective response [11,12], mental fatigue [13], and working stress [14]). The exploited state-/task-related EEG associations can be further leveraged with machine learning to underpin a mobile brain-computer interface (BCI) for a vast range of applications, such as rehabilitative exoskeleton control [15], visual function loss [16], attentional responses [17], lapse mitigation [18], quadcopter control [19], and visual-search games [20]. To this end, a mobile EEG device that enables a valid and reliable measurement of EEG signals over the brain is highly demanded and can play a vital role toward mobile BCI applications in real-world scenarios.…”

Objective Assessment of Impulse Control Disorder in Patients with Parkinson’s Disease Using a Low-Cost LEGO-Like EEG Headset

“…Unlike the bulky gel electrode-headset of laboratories, wearable technology allows the recording of brain activity using dry/saline electrodes, wireless transmission, and a minimized amplifier [16][17][18]. Furthermore, the easy-to-setup wearability not only makes the EEG measurement more user/patient-friendly and less headset-calibrated, but also considerably promotes realistic EEG applications in daily life [19][20][21].…”