The Tbit™ System will detect S100B and GFAP concentrations with the blood specimen to produce and compare repeated measures from 3 blood samples from 3 fingersticks from one subject and one 1 venous whole blood sample will be collected from the same subject, on 3 different Tbit™ System by 3 different operators.

Inclusion Criteria:

• At least 18 years of age
• Presents to the Emergency Department with suspected traumatic brain injury
• Blood sample collected for Tbit™ System within 12 hours of injury
• Willing and able to provide informed consent or obtain consent from legal authorized representative (LAR)

Exclusion Criteria:

• Suspect of ischemic or hemorrhagic stroke with subsequent incidental trauma based on ED examination
• Subject suspect of need of craniotomy for the acute trauma for this event
• External signs compatible with a depressed skull fracture based on ED exam
• Subject requiring administration of blood transfusion after injury and prior to study blood draw
• Subject for whom timing of injury is unable to be estimated within 1 hour of certainty
• Subject who had neurodegenerative disease or other neurological disorder including dementia, Parkinson's disease, multiple sclerosis, seizures, brain tumors, stroke or TIA within the last 30 days, or history of neurosurgery
• Known or suspected to be pregnant
• Prisoner or under incarceration
• Participating in another clinical research study prior to this study completion