Automated Extracranial Internal Carotid Artery Ultrasound Sensor for Traumatic Brain Injury

Study Overview
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Brief Summary
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Traumatic brain injury (TBI) affects 1.7 million people in the United States each year, resulting in 2.5 million emergency department visits, 280,000 hospitalizations, >50,000 deaths, and more than $60 billion in economic cost. TBI also affects >30,000 military personnel annually and almost 8% of veterans who received care between 2001 and 2011. Post-traumatic neurologic outcome depends on the severity of initial injuries and the extent of secondary cerebral damage. Ischemia is the most common and devastating secondary insult. Ischemic brain damage has been identified histologically in  90% of patients who died following closed head injury, and several studies have associated low cerebral blood flow (CBF) with poor outcome. Specifically, CBF of less than 200 ml/min has been shown to be the critical lower threshold for survival in neurointensive care patients. In addition to intracranial hypertension and cerebral edema, systemic hypotension and reduced cardiac output contribute substantially to posttraumatic cerebral ischemia. Additionally, the carotid artery is the most common site of blunt cerebral vascular injury (BCVI), which may further compromise CBF and cause subsequent death or debilitating stroke. Specifically, high grade internal carotid arterial (ICA) injuries are associated with the highest mortality and stroke rate. The investigators' goal is to develop of a wearable noninvasive, continuous, automated ultrasound sensor to accurately measure extracranial ICA flow volume. In doing so, the investigators aim to enable early detection of CBF compromise, thereby preventing secondary ischemic injuries in TBI patients. To achieve this goal, the investigators plan to first build a prototype wearable ICA ultrasound senor with integrated signal processing platform, then test its accuracy in an in vitro system and healthy human subjects.

Official Title
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Automated Extracranial Internal Carotid Artery Ultrasound Sensor for Traumatic Brain Injury

Conditions
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Traumatic Brain Injury

Intervention / Treatment
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* Device: Automated extracranial internal carotid artery ultrasound sensor


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy volunteers Age 18 or older Exclusion Criteria: Claustrophobic Hyperventilation or panic disorders Pregnant Have metal implants or cannot pass the MRI screening questions

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Healthy subjects<br>Healthy adult volunteers (age 18 or greater) that are not claustrophobic, do not have hyperventilation or panic disorders, not pregnant, have no metal implants and can pass the MRI screening questions. | Device: Automated extracranial internal carotid artery ultrasound sensor<br>* The investigators' goal is to develop a wearable noninvasive, continuous, automated ultrasound sensor to accurately measure arterial blood flow volume outside of the head. Ultrasound uses sound waves to create a picture. In doing so, the investigators hope to detect CBF compromise early, preventing secondary injuries in TBI patients.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Internal carotid artery blood flow | The investigators will measure volume of blood flow through the extracranial internal carotid artery using the ultrasound sensor and MRI | 5 minutes before ultrasound or MRI measurement until 15 minutes after the measurement | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| End tidal CO2 level | End tidal carbon dioxide level during normal, hypoventilation, and hyperventilation | 5 minutes before ultrasound or MRI measurement until 15 minutes after the measurement |