The aim of this pilot study is to collect data on stroke patients and non-stroke patients or healthy volunteers using the BrainPulse Stroke Monitor. Subject characteristics, diagnostic procedures and clinical outcomes will be documented as part of the data collected to assess the clinical utility of the BrainPulse device. All eligible patients and healthy volunteers will be enrolled and assigned to a study Group based on confirmation of their diagnosis: Acute Ischemic Stroke, Hemorrhagic Stroke, Transient Ischemic Attack or No Stroke. The data collected from the BrainPulse will be compared across the different study groups in an attempt to distinguish stroke from other non-stroke conditions that present with similar symptoms and LVO from non-LVO types of strokes. Further assessments will also be made to evaluate if the BrainPulse can identify the presence of stroke.

The study is a prospective, non-randomized, non-blinded, hospital-based study of patients presenting with acute stroke symptoms within 48 hours of symptom onset (last known normal or actual time) as evidenced by radiological imaging. The study will be executed in two parts: Study Phase I and Study Phase II. Each study phase will consist of the same sequence of events and study procedures. The first part of the study is designed to enroll a smaller sample size to evaluate the feasibility of incorporating the BrainPulse device in the Stroke patient care workflow.

Patients will be consecutively recruited and once patients have met eligibility, they will be assigned to one of the four study Groups based on their confirmed clinical diagnosis. Each subject will complete one BrainPulse recording before neuro-intervention and within four hours of IV pharmacologic intervention. All subjects will also complete comprehensive neurological, cognitive and NIH Stroke Scale (NIHSS) assessments. Additionally, Ischemic Stroke subjects (Group A) that receive neuro-intervention will complete one additional, and optional BrainPulse recording along with a neurological exam after intervention. If these procedures have been completed as part of standard of care, the data can be captured directly from the medical records. If such procedures were not conducted as part of hospital's standard of care, they will need to be completed for the purpose of the study.

Inclusion Criteria:

1. Male or female subjects 18 years or older

2. Patient undergoes or will undergo radiological imaging (CT/MR) as part of stroke evaluation (n/a for Group D2)

3. Demonstrated at least 1 of the following symptoms (n/a for Group D2):

   1. Hemiparesis, monoparesis, or quadriparesis
   2. Hemisensory deficits
   3. Monocular/binocular visual loss
   4. Visual field deficits
   5. Diplopia
   6. Dysarthria
   7. Facial droop
   8. Ataxia
   9. Vertigo
   10. Aphasia
   11. Severe and sudden onset of headache
   12. Nausea, and/or vomiting
   13. Dizziness
   14. Altered or loss of consciousness
   15. Imbalance/ Incoordination

4. Last known normal or actual time point, whichever is known, since commencement of symptoms < 48 hours prior to enrollment (n/a for Group D2)

5. Consent procedures followed per applicable IRB approvals at site

Exclusion Criteria:

1. Not a candidate for radiological imaging (CT/MR) or angiography (CTA/MRA/DSA) (n/a for Group D2)
2. Patient meets the hospital criteria for brain death
3. Wound or laceration on the head in the area of one of the BrainPulse sensors that would impede use of the BrainPulse device
4. Any serious medical, social or psychological condition that in the opinion of the investigator would disqualify a patient from participation
5. Symptoms due to head trauma
6. IV tPA commenced or completed > 4 hours ago
7. Any neuro-intervention commenced or completed between admission and time of enrollment
8. If does not satisfy the eligibility criteria for groups A, B, C, and D.

The study is expected to enroll up to 289 subjects in total for both parts of the study. During Part I of the study, 40 subjects are expected to be enrolled, of which 20 participants will be assigned to Group A, 5 participants assigned to Group B, 5 participants assigned to Group C, 5 participants assigned to Group D and up to 5 screen failures. In the second part of the study, up to 249 subjects are expected to be enrolled, of which 57 participants will be assigned to Group A1, 57 participants assigned to Group A2, 36 participants assigned to Group D1, and up to 62 participants assigned to group D2, and up to 37 screen failures.