Subjects with thromboembolic disease or at high-risk for thromboembolic conditions diagnosed with ultrasound or other standard of care techniques will be recruited to estimate the feasibility of a device to detect in vivo CBCs.

There are no current gold standards to detect circulating blood clots. The sensitivity of most current methods to detect CBCs is poor when low numbers are present in the host. A novel method of detecting circulating blood clots, PAFC, may improve detection of CBCs and, if so, ultimately may reduce complications related to previously undetected clots.

Inclusion Criteria

• Men and women, 18 years old and older.
• Evidence of current venous or arterial thromboembolic disease diagnosed by standard of care clinical, radiographic, or laboratory testing or acute ischemic stroke.
• Informed consent provided by the subject.

Exclusion Criteria

• Pulmonary embolus with a need for mechanical ventilation or other ventilator support (may be on oxygen delivered by nasal cannula or mask at an FiO2 of ≤ 0.40)
• Acute coronary syndrome (including unstable angina)
• Significant cardiac arrhythmia (may have atrial fibrillation controlled with medication)
• Intracardiac thrombus
• Any embolus or thrombus requiring vascular surgery or interventional radiology to attempt acute embolectomy or thrombectomy
• Sickle cell disease with vaso-occlusive crisis
• Sepsis or life-threatening infection
• Traumatic injury requiring hospitalization (within 30 days prior to enrollment)
• Pregnancy or breastfeeding
• Severe mental illness
• Other conditions deemed by the investigators to put the subject at greater risk