An observational study in Blast Overpressure Exposure, Blast Injuries and Brain Health, sponsored by Neurable, Inc. Completed at 1 site in Canada. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-10.
Sponsored by Neurable, Inc · Observational
The purpose of this study is to learn whether headsets that measure brainwaves can find early signs of changes in brain health in tactical operators who train near explosive blasts.
Tactical operators are often near blasts during training. These blasts might change how the brain works over time, even if a person feels fine now. This study uses headsets that measure electrical brainwaves to see if they can detect early changes before they cause problems such as memory loss or blurred vision.
The main questions it aims to answer are:
This is an observational study. It adds no new training activities and does not change how close participants stand to a blast or how many blasts they are near. The research team observes and records during training that is already scheduled.
About 12 people taking part in Guild Solutions breaching training near Ottawa, Canada will join. The study lasts five days. Most sessions take about 5 to 10 minutes, except the Day 1 baseline session, which takes longer.
Participants will:
The headsets use passive sensors that only listen to the brain's own electrical activity. They do not send electricity into the head. These devices have not been approved by Health Canada. They are used in this study only as non-invasive tools to record research data; the study is not evaluating the devices for medical safety or effectiveness.
Anyone who feels uncomfortable or no longer wants to take part can remove the headset and leave the session at once. On the breaching range, participants should speak with an onsite instructor first, for their own safety.
Taking part is voluntary. Individual results are not shared with Guild Solutions leadership or instructors in any way that would identify a participant, and the decision to join or not join has no effect on training, performance appraisal, or employment.
Background and rationale
Tactical operators are repeatedly exposed to sub-concussive blast overpressure during breaching training. Current safety standards rely primarily on distance-based calculations and subjective symptom reporting, which may fail to capture acute neural strain. Prior work in mild traumatic brain injury suggests quantitative EEG is sensitive to changes in Delta, Theta, and Alpha power spectra. This observational study investigates whether non-invasive EEG acquired with dry-electrode, EEG-integrated personal protective equipment can detect pre-symptomatic physiological deviation from an individual baseline in an operational training environment.
Specific aims
Validate the feasibility of collecting high-fidelity EEG during active breaching using EEG-integrated tactical hearing protection (AMP Neuro).
Identify EEG biomarkers associated with acute blast overpressure exposure, specifically Delta and Theta power increases and Alpha suppression.
Correlate objective measures of physiological change and blast dosimetry with subjective symptom report using the Neurobehavioral Symptom Inventory (NSI).
Design
Observational, longitudinal, within-subject cohort study conducted alongside a pre-scheduled tactical training curriculum. Participants serve as their own controls, with post-exposure data compared against each participant's Day 1 baseline. Approximately 12 participants will enroll. Study duration per participant is five days.
The study is non-interventional and introduces no new physical maneuvers; it does not alter the frequency, intensity, or proximity of blast exposures already required by the training syllabus. All participants provide neural snapshot EEG data and wear a blast sensor during breaching exercises. All participants also wear the AMP Neuro headset during active breaching at some point during the training week: because each breaching round involves three active breachers, AMP Neuro wear rotates in groups of three in step with the training rotation.
Data collection modalities
Schedule of assessments
Recruitment and consent occur on Day 1 via a verbal briefing led by the Principal Investigator, with a private room available for individual review and signing of the informed consent form. No research procedures begin before the form is signed by both the participant and study personnel.
Day 1 - intake and baseline:
Days 2-5 - training days with potential blast overpressure exposure:
Participation requires approximately 5 to 10 minutes per session, apart from the Day 1 baseline session.
Devices
Both EEG systems use passive dry-electrode sensors and deliver no energy or electrical stimulation to the participant. The MW75 Neuro is a commercial-form-factor over-ear headphone used for stationary neural snapshots. The AMP Neuro integrates EEG sensing into tactical hearing protection for recording during active breaching. The Blast Tracker 4 is a passive pressure monitor mounted to existing gear. The devices have not been approved by Health Canada and are used solely as non-invasive research data collection tools; they are not the subject of investigation and will not be evaluated for medical safety or effectiveness.
Statistical analysis
Repeated-measures design. Paired t-tests and linear mixed-effects models will test for significant deviation in EEG power bands from individual baseline. Pearson correlations will assess associations between EEG power bands and NSI scores, and between Blast Tracker 4 dosimetry and both EEG perturbation and NSI scores.
Data management and privacy
Participant names and dates of birth are replaced with a coded participant ID at intake, and participants state this ID when completing daily questionnaires. A single password-protected file linking names to codes is held by the Principal Investigator and deleted at the completion of data collection. Individual results are not shared with Guild Solutions leadership or trainers in any way that would identify a participant. All data are held on locked systems or encrypted cloud servers. Source records may be reviewed by sponsor representatives, the Advarra IRB, and regulatory authorities including Health Canada and the US FDA for monitoring, auditing, and data verification.
Risks, benefits, and withdrawal
Risks are minimal: mild discomfort from extended sensor wear, comparable to wearing headphones, and a small risk of privacy breach, mitigated by the safeguards above. The AMP Neuro is not expected to affect hearing protection; a participant who judges its use unsafe on the range may stop using it, coordinating first with an onsite instructor. There is no intended clinical benefit to participants and no monetary compensation. Participation is voluntary, may be discontinued at any time without penalty, and participants who withdraw may request destruction of data already collected.
24 studies on the registry are indexed under Blast Injuries; 7 are open to participants now.
This study's enrollment of 12 is below the median of 100 across 13 observational studies indexed under Blast Injuries.
Browse Blast Injuries studies →This is the only study on the registry with Neurable, Inc as lead sponsor.
Counted across the registry records on this site, refreshed daily.
Participants are tactical operators enrolled in a pre-scheduled explosive breaching training course delivered by Guild Solutions at Royal Canadian Mounted Police facilities in the Ottawa-Gatineau region of Canada. All are healthy adults at least 18 years of age; a minimum age of 18 is a prerequisite for enrollment in the training course itself, and no upper age limit applies. Approximately 12 participants will be enrolled from a single course cohort.
Recruitment occurs in person through a verbal briefing to the assembled class, delivered by the Principal Investigator on the first day of the course, with a private room available for individual review and signing of the consent form. Enrollment is voluntary and open to any course participant who meets the eligibility criteria. Because the sample is drawn from one training cohort at a single site, findings may not generalize to other operator populations or to other blast exposure profiles.
Inclusion Criteria:
Exclusion Criteria (all criteria are self-reported; medical records are not reviewed):
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Personnel completing the Guild Solutions explosive breaching curriculum monitored with EEG, blast dosimetry, balance and cognitive assessment, and symptom report across five training days.
Other: Blast overpressure exposure during explosive breaching training
Participants are exposed to sub-concussive blast overpressure as part of the pre-existing Guild Solutions explosive breaching curriculum. The study does not assign, add, or modify exposures. It does not change the number of blast events, the charges used, or participant proximity to the breaching target. Participants rotate through standard training positions, including the three active breacher roles in each round, according to the training syllabus. Exposure is measured rather than administered. All participants wear a Blast Tracker 4 pressure sensor on the belt or helmet rail during breaching exercises to quantify the pressure and force of each nearby blast event. Individual exposure is further characterized by a self-reported count of blast overpressure events in the three months before enrollment, collected at intake.
Feasibility of EEG data collection during active explosive breaching, measured as the proportion of AMP Neuro recordings meeting signal-quality criteria
Percentage of AMP Neuro recording epochs retained after automated movement-artifact rejection, out of all epochs recorded during active breaching. Reported per session and aggregated across the cohort, with the proportion of sessions yielding analyzable data.
Time frame: During each breaching exercise, Days 2 through 5
Change from baseline in normalized Delta band power
Delta band power derived from 2-minute resting-state neural snapshots recorded with the MW75 Neuro headset, with eyes-open and eyes-closed segments analyzed separately. Values are expressed as a normalized index in which 100 represents the mean of a general healthy adult reference population and scores from 75 to 125 fall within one standard deviation of that mean. The index is continuous with no fixed minimum or maximum. Higher scores indicate greater Delta band power. Because the index is centered on a population mean, neither direction represents a uniformly better or worse outcome; deviation from each participant's own Day 1 baseline in either direction is the outcome of interest. The hypothesized direction following blast overpressure exposure is an increase.
Time frame: Day 1 baseline; then morning, within 60 minutes before and within 60 minutes after each breaching exercise, and evening, Days 2 through 5
Change from baseline in normalized Theta band power
Theta band power derived from 2-minute resting-state neural snapshots recorded with the MW75 Neuro headset, with eyes-open and eyes-closed segments analyzed separately. Values are expressed as a normalized index in which 100 represents the mean of a general healthy adult reference population and scores from 75 to 125 fall within one standard deviation of that mean. The index is continuous with no fixed minimum or maximum. Higher scores indicate greater Theta band power. Because the index is centered on a population mean, neither direction represents a uniformly better or worse outcome; deviation from each participant's own Day 1 baseline in either direction is the outcome of interest. The hypothesized direction following blast overpressure exposure is an increase.
Time frame: Day 1 baseline; then morning, within 60 minutes before and within 60 minutes after each breaching exercise, and evening, Days 2 through 5
Change from baseline in normalized Alpha band power
Alpha band power derived from 2-minute resting-state neural snapshots recorded with the MW75 Neuro headset, with eyes-open and eyes-closed segments analyzed separately. Values are expressed as a normalized index in which 100 represents the mean of a general healthy adult reference population and scores from 75 to 125 fall within one standard deviation of that mean. The index is continuous with no fixed minimum or maximum. Higher scores indicate greater Alpha band power. Because the index is centered on a population mean, neither direction represents a uniformly better or worse outcome; deviation from each participant's own Day 1 baseline in either direction is the outcome of interest. The hypothesized direction following blast overpressure exposure is a decrease.
Time frame: Day 1 baseline; then morning, within 60 minutes before and within 60 minutes after each breaching exercise, and evening, Days 2 through 5
Association between change in EEG band power and measured blast overpressure exposure
Correlation between within-participant change in Delta, Theta, and Alpha power and blast dosimetry recorded by the Blast Tracker 4, including peak overpressure and cumulative exposure across the training day. Assessed by Pearson correlation.
Time frame: Days 2 through 5, pairing each pre-to-post breaching EEG change with the dosimetry recorded during that exercise
Change from baseline in Neurobehavioral Symptom Inventory (NSI) score
The Neurobehavioral Symptom Inventory (NSI) is a 22-item self-report questionnaire in which each item is rated on a 5-point scale from 0 (None) to 4 (Very Severe). The total score is the sum of all 22 items and ranges from 0 to 88. Higher scores indicate greater symptom burden, so an increase represents a worse outcome. Change is calculated against each participant's Day 1 intake rating.
Time frame: Day 1 intake; then morning, within 60 minutes before and within 60 minutes after each breaching exercise, and evening, Days 2 through 5
Change from baseline in postural stability measured by the Sway Balance assessment
The Sway Balance score is generated by the Sway Concussion application (Healthy Roster) from accelerometer data collected on a mobile device held at the sternum across specified stances, including tandem stance and single-leg stance. Scores range from 0 to 100. Higher scores indicate better postural stability; a decrease from baseline represents a worse outcome. The Day 1 baseline comprises a practice round plus a minimum of two trial rounds, with a third round administered if between-round variance exceeds the vendor's preset threshold; subsequent assessments use a single round. Change is calculated against each participant's own Day 1 baseline.
Time frame: Day 1 baseline; then morning and evening, Days 2 through 5
Change from baseline in the Sway Reaction Time score
The Sway Reaction Time score is generated by the Sway Concussion application (Healthy Roster) from a task requiring the participant to move the mobile device when the screen changes color. The score is reported as raw reaction time in milliseconds. There is no fixed maximum; the fixed minimum is 0ms. Lower values indicate faster reaction time and better performance; an increase from baseline represents a worse outcome. Change is calculated against each participant's own Day 1 baseline.
Time frame: Day 1 baseline; then morning and evening, Days 2 through 5
Change from baseline in the Sway Working Memory score
The Sway Working Memory score is generated by the Sway Concussion application (Healthy Roster) from a task in which three letters are presented for three seconds, followed by a block-tapping sequence that lengthens each round until an error occurs, after which the participant recalls the three letters. Scores range from 0 to 100. Higher scores indicate better working memory performance; a decrease from baseline represents a worse outcome. Change is calculated against each participant's own Day 1 baseline.
Time frame: Day 1 baseline; then morning and evening, Days 2 through 5
Association between measured blast overpressure exposure and Neurobehavioral Symptom Inventory (NSI) total score
Correlation between cumulative blast impulse recorded by the Blast Tracker 4 and the Neurobehavioral Symptom Inventory (NSI) total score. The NSI is a 22-item self-report questionnaire, each item rated 0 (None) to 4 (Very Severe), with a total score ranging from 0 to 88; higher scores indicate greater symptom burden and a worse outcome. Assessed by Pearson correlation.
Time frame: Days 2 through 5
Sleep duration and substance use as covariates of EEG and symptom measures
Self-reported hours of sleep and quantity of caffeine, alcohol, and nicotine consumed in the preceding 24 hours, collected each morning. Used as covariates in models of EEG band power change and symptom score change.
Time frame: Day 1 intake; then each morning, Days 2 through 5
Number of participants reporting discomfort or skin irritation attributable to headset wear
Count of participants who report discomfort or skin irritation attributable to wearing the MW75 Neuro or AMP Neuro headset at any point during the study, recorded by research staff. Unit of measure: participants.
Time frame: Day 1 through Day 5
Number of sessions in which headset use was discontinued
Count of sessions in which headset use was discontinued before completion, either by the participant or at the direction of a range instructor, recorded by research staff. Unit of measure: sessions.
Time frame: Day 1 through Day 5
Plan to share: No — Individual participant data will not be shared with researchers outside the study team. Approximately 12 participants are enrolled from a single training cohort at one site; combined with the distinctive occupational population and site-specific blast exposure records, individual-level data carry a meaningful risk of re-identification even after removal of direct identifiers. The informed consent form commits to a siloed data approach in which individual results are not disclosed in any way that would identify a participant, and describes disclosure only to the sponsor, the reviewing IRB, and regulatory authorities for monitoring and audit purposes. Findings will be disseminated as aggregate, de-identified results through peer-reviewed publication.
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