The Neuralert monitoring system, a non-invasive device worn on each wrist, is designed to provide continuous monitoring and expedited recognition of stroke by identifying asymmetry in the extremities, facilitating patient treatment and improving outcomes. This study is designed to evaluate the safety and effectiveness of the Neuralert Monitor. This study aims to show that the device produces fewer than 2 false alarms per patient per day on average, and that the device detects stroke with a sensitivity significantly greater than a device producing 2 random alerts per day.

Inclusion Criteria: (all must be yes)

1. Male or female age ≥ 22 years

2. Admitted or planned admission to one of the participating hospitals and followed by the Cardiothoracic (CT) Surgery or Vascular Surgery services

3. Considered at high risk for stroke while in the hospital based on:

   • Interventions or procedures that are high-risk for stroke performed during the hospitalization, which may include:

     • Intracardiac surgical or endovascular procedures, including valve replacement
     • Ascending aorta or aortic arch surgical or endovascular repair
     • Open surgical or endovascular carotid revascularization

   • Other cardiac procedures along with a high-risk medical history:

     • Age ≥ 80 years
     • Prior stroke/ transient ischemic attack (TIA)
     • Hypercoagulable state (i.e., prior clotting events attributed to active malignancy or a diagnosed thrombophilia) requiring lifelong anticoagulation
     • Severely reduced left ventricular cardiac ejection fraction (i.e., <30%) or anterior left ventricular wall akinesis
     • Atrial fibrillation

Exclusion Criteria: (all must be no)

1. Any medical or psychological conditions that, in the opinion of the investigator, would compromise the subject's safety or successful participation in the study
2. Baseline preoperative asymmetric upper extremity weakness as assessed by the Investigator, defined as a differential in the NIHSS upper extremity motor score between the two arms of >0
3. Above the wrist amputation
4. Unwilling to provide informed consent or no legally authorized representative willing to provide consent if the patient is unable
5. Currently imprisoned