Ultrasound Perfusion Estimation for Assessment of Peripheral Arterial Disease

Inclusion Criteria: Patient volunteers: * Male and Female, ages 18 years old and up * Symptom of claudication and suspected for PAD * Scheduled for vascular testing. Healthy volunteers: * Male and female, ages 18-75 years old and up * Normal BMI * No history of smoking, cardiovascular disease, or diabetes. Exclusion Criteria: Patient volunteers: * Patients with gangrene * Patients having surgery or stent * Patients with ulcer on their leg * Any health condition that does not allow proper use of ultrasound scanning * People considered in "vulnerable" populations. Healthy volunteers: * Include volunteers with BMI not more than 30 * No history of smoking * No history of (diabetes, hypertension, cardiovascular diseases) * People considered in "vulnerable" populations.