Biomarkers of Brain Health in Blast Overpressure Exposure

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

Interventions

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.

Sponsors & Collaborators

• Neurable, Inc

  lead INDUSTRY

Principal Investigators

• Alicia Howell-Munson, PhD · Neurable, Inc

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2026-08-10

Primary Completion

2026-08-14

Completion

2026-08-21

Countries

• Canada

Study Locations