The objective of the study is to evaluate, in a blinded fashion, the effectiveness of the Nautilus BrainPulse device when used as an aid in the diagnosis of concussion.

This is a prospective, non-randomized, blinded, matched control study of young athletes (ages 10-25 years old) in competitive sports (Cohort A: higher-risk of concussion, Cohort B: lower-risk of concussion) to assess the effectiveness of the Nautilus BrainPulse device when used as an aid in the diagnosis of concussion.

The Nautilus BrainPulse is intended for use on a patient's head to non-invasively detect, amplify and capture the brain pulse, the brain motion caused by pulsatile blood flow from the cardiac cycle. The Nautilus BrainPulse analyzes the captured data to provide an aid in diagnosing an episode of concussion.

Inclusion Criteria:

1. Male or female subjects between 10 and 25 years of age (middle school, high school or college-age)
2. Team member, where the team meets at least twice a week
3. Willing and able to participate in all study evaluations and allow access to medical testing and records
4. Signed informed consent, or have a legally authorized representative willing to provide informed consent on behalf of the subject if the subject is a minor

Exclusion Criteria:

1. Documented history of a concussion diagnosed by a physician in the last two months assessed via interview with athlete
2. Known history of any cognitive deficits that diminish ability to administer study assessments, such as SCAT3™
3. Wound on the head in the area of one of the Nautilus BrainPulse sensors that would impede use of the Nautilus BrainPulse device
4. Inability to obtain a valid SCAT3 and ImPACT® baseline assessment of concussion
5. Any serious medical, social or psychological condition that in the opinion of the investigator would impair ability to provide informed consent or otherwise disqualify a patient from participation

Cohort A: High-Risk of Concussion Middle school, high school and college athletes of either gender participating in sports where high-risk of concussion is anticipated: football, soccer, lacrosse, hockey, basketball, ice hockey, field hockey, rugby, cheerleading, boxing, and gymnastics.

Cohort B: Low-Risk of Concussion Middle school, high school and college athletes of either gender participating in sports where low-risk of concussion is anticipated: swimming, track, volleyball, baseball, softball and golf.