Biomarkers of Brain Health in Blast Overpressure Exposure (Guild Blast Ottawa, Canada 2026)
Biomarkers of Brain Health in Blast Overpressure Exposure (Guild Blast Ottawa, Canada 2026)
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.
Inclusion Criteria:
Exclusion Criteria (all criteria are self-reported; medical records are not reviewed):
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.