Biomarkers of Brain Health in Blast Overpressure Exposure

NCT07783048 | Completed

• 1 other identifier: Blast-Pro00095892
• Study Type: observational
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

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:

• Can useful brainwave data be recorded during real breaching training, using sensors built into tactical hearing protection?
• Do brainwave patterns change after blast exposure, compared with a person's own Day 1 baseline?
• Do those brainwave changes line up with the amount of blast pressure a person was exposed to, with changes in balance and thinking, and with the symptoms they report? 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:
• Answer questions on Day 1 about sleep, stress, and habits; about any symptoms they have now, such as dizziness; and about how many blasts they were near in the past three months
• Take balance and thinking tests on a phone or tablet using the Sway Concussion app by Healthy Roster. On Day 1 these take about 15 minutes together (about 7 minutes each). On later days they take about 3 minutes each
• The balance test asks the participant to hold certain stances, such as one foot in front of the other, or standing on one foot. The thinking tests ask the participant to move the device when the screen changes color, and to remember three letters while playing a Simon-Says-style game
• Sit still for 3-minute "neural snapshot" brainwave recordings, alternating between eyes open and eyes closed. On training days these are collected in the morning, before and after each breaching exercise, and in the evening
• Answer a short symptom questionnaire in the morning, before and after each breaching exercise, and in the evening, plus a daily log of sleep and substance use
• Wear a Blast Tracker 4 blast sensor during breaching exercises
• Wear the AMP Neuro headset, which is built into tactical hearing protection, during breaching exercises. Because each breaching round has three active breachers, participants wear it in rotating groups of three, so everyone wears it at some point during the week 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.

Conditions

Blast Injuries; Brain Health; Blast Overpressure Exposure; Occupational Exposure; Subconcussive Blast Exposure

Keywords

blast overpressure; breaching; explosive breaching; energetics breaching; electroencephalography; EEG biomarkers; quantitative EEG; wearable EEG; dry electrode EEG; blast dosimetry; tactical operators; law enforcement; personal protective equipment; tactical hearing protection; Neurobehavioral Symptom Inventory; balance assessment; reaction time; working memory; neural snapshot; repeated blast exposure; brain health monitoring

Outcome Measures

Primary Outcomes (4)

• 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.

  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.

  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.

  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.

  Day 1 baseline; then morning, within 60 minutes before and within 60 minutes after each breaching exercise, and evening, Days 2 through 5

Secondary Outcomes (6)

• Association between change in EEG band power and measured blast overpressure exposure

  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

  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

  Day 1 baseline; then morning and evening, Days 2 through 5

• Change from baseline in the Sway Reaction Time score

  Day 1 baseline; then morning and evening, Days 2 through 5

• Change from baseline in the Sway Working Memory score

  Day 1 baseline; then morning and evening, Days 2 through 5

Other Outcomes (3)

• Sleep duration and substance use as covariates of EEG and symptom measures

  Day 1 intake; then each morning, Days 2 through 5

• Number of participants reporting discomfort or skin irritation attributable to headset wear

  Day 1 through Day 5

• Number of sessions in which headset use was discontinued

  Day 1 through Day 5

Study Arms (1)

Tactical operators exposed to blast overpressure

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

Interventions

Blast overpressure exposure during explosive breaching training OTHER

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.

Tactical operators exposed to blast overpressure

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

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.

You may qualify if:

• Currently enrolled participant in the Guild Solutions explosive breaching training course
• At least 18 years of age
• Fluent in English, sufficient to understand the consent form and study instructions
• Able and willing to provide written informed consent
• Willing to wear the study EEG headsets during assigned portions of the study

You may not qualify if:

• Major head injury within the past 6 months
• Regular use of anti-seizure or sedative (sleep) medication
• Known skin allergy or sensitivity to headset materials, including silver, silver-chloride, or vinyl

Sponsors & Collaborators

• Neurable, Inc: lead

Study Sites (1)

Royal Canadian Mounted Police

Orléans, Ontario, K1C 7K9, Canada

Location

Related Publications (3)

• LaValle CR, Carr WS, Egnoto MJ, Misistia AC, Salib JE, Ramos AN, Kamimori GH. Neurocognitive Performance Deficits Related to Immediate and Acute Blast Overpressure Exposure. Front Neurol. 2019 Sep 13;10:949. doi: 10.3389/fneur.2019.00949. eCollection 2019.

  PMID: 31572285 BACKGROUND

• Ianof JN, Anghinah R. Traumatic brain injury: An EEG point of view. Dement Neuropsychol. 2017 Jan-Mar;11(1):3-5. doi: 10.1590/1980-57642016dn11-010002.

  PMID: 29213487 BACKGROUND

• Edlow BL, Bodien YG, Baxter T, Belanger HG, Cali RJ, Deary KB, Fischl B, Foulkes AS, Gilmore N, Greve DN, Hooker JM, Huang SY, Kelemen JN, Kimberly WT, Maffei C, Masood M, Perl DP, Polimeni JR, Rosen BR, Tromly SL, Tseng CJ, Yao EF, Zurcher NR, Mac Donald CL, Dams-O'Connor K. Long-Term Effects of Repeated Blast Exposure in United States Special Operations Forces Personnel: A Pilot Study Protocol. J Neurotrauma. 2022 Oct;39(19-20):1391-1407. doi: 10.1089/neu.2022.0030. Epub 2022 Jun 29.

  PMID: 35620901 BACKGROUND

MeSH Terms

Conditions

Blast Injuries

Condition Hierarchy (Ancestors)

Barotrauma; Wounds and Injuries

Study Officials

• Alicia Howell-Munson, PhD

  Neurable, Inc

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 18, 2026
• First Posted: August 24, 2026
• Study Start: August 10, 2026
• Primary Completion: August 14, 2026
• Study Completion: August 21, 2026
• Last Updated: September 10, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)