Neuroergonomic Analysis of a Brain-Computer Interface Device (BCI)

November 2, 2026 updated by: Henrique Cunha Carvalho, Universidade Federal do Paraná

Neuroergonomic Analysis of a Brain-Computer Interface (BCI) Device Based on EEG Signals and User Experience

This study evaluates the mental workload and user experience associated with a Brain-Computer Interface (BCI) device called Exobots. The Exobots system uses a non-invasive electroencephalography (EEG) headset to detect neural signals and control a robotic glove that assists hand movement. The primary goal is to assess how three different system sensitivity levels (low, medium, high) impact mental effort, usability, and overall user perception. Healthy adult volunteers (students and staff from IFPR and UFPR) will participate in a single experimental session. During the session, they will perform a repeated mental imagery task (imagine hand movement) while the EEG records their brain activity. After each sensitivity block, participants will complete standardized questionnaires (NASA Task Load Index and User Experience Questionnaire) and a semi-structured qualitative interview about their experience. By combining objective neurophysiological data with subjective feedback, this research aims to identify optimal sensitivity thresholds that minimize cognitive strain and maximize user comfort. The findings are expected to provide technical recommendations for designing more adaptive, user-centered BCI systems for future neurorehabilitation applications.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Background and Rationale

Brain-Computer Interfaces (BCIs) are increasingly employed in neurorehabilitation settings to assist individuals with motor impairments. While these systems enable direct neural control of assistive devices, there is a significant gap in understanding the cognitive demands they impose on users. Excessive mental workload can lead to frustration, disengagement, and suboptimal therapeutic outcomes. This study addresses this gap by applying a neuroergonomic approach-integrating objective neurophysiological measures with subjective user experience (UX) assessments.

Objectives

Primary Objective: To evaluate cognitive load during interaction with the Exobots BCI device by integrating neurophysiological metrics (EEG), psychometric UX scores, and subjective user perceptions.

Secondary Objectives:

  1. To map neural activity patterns, focusing on theta, alpha, and beta frequency bands, during BCI interaction.
  2. To correlate neurophysiological indicators of mental effort with usability and UX measures obtained via the NASA-TLX and UEQ.
  3. To identify preliminary operational sensitivity threshold parameters established during individual device calibration.
  4. To analyze participants' subjective perceptions of the physical BCI interface using a semi-structured questionnaire with open-ended questions and visual cards.
  5. To formulate technical recommendations for BCI interface design based on the integrated analysis of neurophysiological, psychometric, and qualitative data.

Study Design

This is an interventional, single-group, experimental study without a control arm. All participants will undergo the same protocol, testing three distinct sensitivity levels (low, medium, high) in a within-subjects design, with the order of sensitivity levels counterbalanced to avoid order effects.

Study Population and Sample Size

Healthy adults (aged 18 years or older) who are students (undergraduate, graduate, technical level) or staff members from the Federal University of Paraná (UFPR) and the Federal Institute of Paraná (IFPR) will be recruited.

The minimum sample size was calculated using G*Power software (version 3.1.9.7) for a bivariate normal correlation model (Exact test, Family: Correlation). Considering an expected effect size of r = 0.50, a significance level of α = 0.05, and a statistical power of (1-β) = 0.80, the calculation indicated a minimum of 29 participants. To ensure statistical robustness and account for potential data loss due to EEG artifacts or voluntary dropouts, the target enrollment is set at 30 participants, with recruitment extended to up to 60 individuals if necessary.

Intervention and Procedures

Screening and Consent: Interested individuals will receive and sign the Informed Consent Form (TCLE). A screening questionnaire will be administered to verify inclusion/exclusion criteria (e.g., no neurological disorders, no recent head injuries).

Device and Preparation: Participants will interact with the Exobots device (provided by Neurobots). An elastic cap equipped with six dry/wet EEG electrodes will be placed on the participant's scalp. A water-based conductive gel will be applied to the contact points to ensure optimal signal quality. The robotic glove will be fitted to the participant's hand.

Calibration: The system will be calibrated to recognize each participant's specific neural patterns. Based on the calibration, three distinct sensitivity thresholds (low, medium, high) will be defined and tested individually.

Experimental Protocol: Each participant will complete a sequence of repeated cycles consisting of four sequential steps:

Prepare: The participant focuses attention on their hand in anticipation of the command.

Think: The participant imagines opening/closing their hand without physically executing the movement. The EEG system detects the motor imagery signal. If the signal is maintained above the predetermined threshold for three consecutive seconds, the robotic glove is activated.

Move: The robotic glove passively moves the participant's hand. The participant is instructed to voluntarily accompany this movement if possible.

Relax: The participant stops focusing and rests for a few seconds before the next cycle.

Each sensitivity level will be tested in blocks of approximately 10 minutes, totaling approximately 35 minutes of effective interaction per participant. Sessions will be scheduled in advance, with at least 48 hours' notice.

Outcome Measures

Neurophysiological: Continuous 6-channel EEG recording throughout the task. Spectral power analysis will focus on theta (4-8 Hz), alpha (8-12 Hz), and beta (12-30 Hz) bands, with particular emphasis on the theta/beta ratio as a validated marker of cognitive load.

Psychometric: Immediately after each sensitivity block, participants will complete the NASA Task Load Index (NASA-TLX) to assess perceived mental, physical, and temporal demands, effort, and frustration. At the end of the entire session, the User Experience Questionnaire (UEQ) will be administered to evaluate pragmatic and hedonic quality attributes.

Qualitative: A semi-structured interview with open-ended questions and thematic cards will be conducted to capture nuanced perceptions regarding the physical interface, comfort, and overall experience that standardized scales may not fully address.

Statistical Analysis

Pearson correlation coefficients will be calculated to assess the association between neurophysiological metrics (e.g., theta/beta ratio, alpha power) and UX scores (UEQ and NASA-TLX). A significance level of p < 0.05 will be adopted. Qualitative data will be analyzed using content analysis techniques to identify recurring themes and insights.

Ethical Considerations

The study protocol was reviewed and approved by the Research Ethics Committee of the Federal Technological University of Paraná (CEP/UTFPR) under Approval Number 8.558.948 (issued July 2, 2026; CAAE: 97426026.1.0000.0165). All procedures comply with Brazilian regulations (Resolution CNS 466/12 and LGPD - Lei Geral de Proteção de Dados).

Participants will be informed that no direct clinical benefits are expected, but that their participation will contribute to the scientific advancement of assistive technologies. Risks are minimal and include mild scalp discomfort from the EEG cap/gel, transient fatigue, or mild frustration. Participants may take breaks or withdraw at any time without penalty. All data will be anonymized, stored on a password-protected local hard drive, and kept confidential.

Data Monitoring Committee

A formal Data Monitoring Committee (DMC) will not be established, as this is a low-risk, non-clinical, academic study with healthy volunteers and no investigational drug or device under IDE regulations.

Study Type

Interventional

Enrollment (Estimated)

30

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Brazil
    • Paraná
      • Curitiba, Paraná, Brazil, 80230901
        • Federal Technological University of Paraná
        • Contact:
        • Contact:
      • Curitiba, Paraná, Brazil

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Technical-level students, undergraduate students, graduate students, and staff members, of both sexes, healthy, affiliated with the Federal University of Paraná (UFPR) or the Federal Institute of Paraná (IFPR).
  2. Age 18 years or older.

Exclusion Criteria:

  1. Use of psychoactive medications.
  2. History of epilepsy or other neurological conditions that would preclude the use of the device.
  3. Severe motor limitations that prevent interaction with the device.
  4. Recent traumatic brain injuries.
  5. Injury, dermatitis, or open wound on the scalp.
  6. Excessive consumption of stimulant substances within the last 4 hours.
  7. Sleep deprivation (less than 5 hours of sleep the previous night) or extreme sleepiness on the day of data collection.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Exobots BCI Device

Participants perform motor imagery tasks (imagining hand movements) while using the Exobots EEG-based BCI device. The system detects neural signals and activates a robotic glove to assist hand movement. Three distinct sensitivity thresholds (low, medium, high) are tested in a counterbalanced order within a single 35-minute experimental session.
Other: EEG-Based Brain-Computer Interface Device

Non-invasive electroencephalography (EEG)-based Brain-Computer Interface (BCI) system consisting of a 6-channel EEG headset and a robotic hand exoskeleton (glove). The device detects motor imagery neural signals associated with imagined hand movements. When the EEG signal is maintained above a predefined sensitivity threshold for three consecutive seconds, the system triggers the robotic glove to passively move the participant's hand. The study evaluates three distinct sensitivity levels (low, medium, high) during individual calibration. The EEG headset uses water-based conductive gel on contact points to ensure signal quality. The device is manufactured by Neurobots and provided for this research.

Other Names:
  • Exobots BCI System

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
EEG Theta/Beta Ratio as a Neurophysiological Marker of Cognitive Load
Time Frame: Measured continuously during each 10-minute experimental block (blocks 1, 2, and 3) throughout the single 35-minute session.

Change in the theta/beta spectral power ratio derived from 6-channel electroencephalography (EEG) recordings during motor imagery (imagined hand movement) tasks. The theta/beta ratio is a validated neurophysiological indicator of cognitive workload and mental effort. This measure is compared across the three distinct device sensitivity levels (low, medium, high) to assess differences in cognitive demand.
Measured continuously during each 10-minute experimental block (blocks 1, 2, and 3) throughout the single 35-minute session.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
NASA Task Load Index (NASA-TLX) Global Workload Score
Time Frame: Immediately after each sensitivity block (3 times total) during the experimental session.

Subjective assessment of perceived mental workload using the NASA-TLX questionnaire. The instrument evaluates six dimensions: mental demand, physical demand, temporal demand, performance, effort, and frustration. The global workload score ranges from 0 to 100, with higher scores indicating greater perceived workload.
Immediately after each sensitivity block (3 times total) during the experimental session.
User Experience Questionnaire (UEQ) Scores
Time Frame: At the end of the entire experimental session.

Assessment of user experience using the standardized User Experience Questionnaire (UEQ). The instrument measures six scales: Attractiveness, Perspicuity, Efficiency, Dependability, Stimulation, and Novelty. Each scale ranges from -3 (very negative) to +3 (very positive), with higher scores indicating a more favorable user experience.
At the end of the entire experimental session.
Qualitative Feedback on BCI Physical Interface and Overall Experience
Time Frame: Immediately following the conclusion of the experimental session.

Thematic content analysis of responses collected through a semi-structured qualitative interview consisting of open-ended questions and visual thematic cards. The analysis captures nuanced perceptions regarding the physical interface (EEG cap and robotic glove), comfort, emotional engagement, usability, and suggestions for device improvement.
Immediately following the conclusion of the experimental session.
Individual Operational Sensitivity Thresholds
Time Frame: During the calibration phase and across all three experimental blocks within the session.

Identification of the optimal sensitivity level (low, medium, or high) for each participant based on the calibration phase and successful device triggering during motor imagery tasks. This measure assesses how individual neural signal characteristics influence the optimal threshold for reliable BCI operation.
During the calibration phase and across all three experimental blocks within the session.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Universidade Federal do Paraná

Collaborators

Instituto Federal do Paraná (IFPR)
Universidade Federal do Paraná (UFPR)
Universidade Tecnológica Federal do Paraná (UTFPR)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

December 28, 2026

Primary Completion (Estimated)

March 31, 2027

Study Completion (Estimated)

March 31, 2027

Study Registration Dates

First Submitted

November 2, 2026

First Submitted That Met QC Criteria

November 2, 2026

First Posted (Actual)

November 6, 2026

Study Record Updates

Last Update Posted (Actual)

November 6, 2026

Last Update Submitted That Met QC Criteria

November 2, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • 97426026.1.0000.0165

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Ethical or Consent Restrictions: Participants may not have given explicit consent for their data to be shared beyond the original study.Legal or Institutional Policies: Data sharing may be restricted by Brazillian laws.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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