The EF5000 Vascular Endothelial Function Tester measures changes in endothelial-mediated vascular tension through a fingertip sensor placed on the finger, capturing variations in fingertip pulse wave amplitude before and after 5 minutes of brachial artery occlusion. The standard 5-minute brachial artery obstruction induces downstream ischemic responses, indirectly reflecting the degree of vasodilation and constriction.

Fingertip arterial tonometry technology (also known as PAT technology) uses optical plethysmography to detect the amplitude of finger pulse waves, reflecting the microcirculatory function of small blood vessels. PAT is a non-invasive method for assessing microvascular endothelial function, measuring changes in finger pulse volume amplitude during reactive hyperemia. By analyzing finger pulse wave amplitude, it evaluates endothelial function, with the calculated endothelial function index—reactive hyperemia index (RHI)—serving as a measure of endothelial health.

PAT correlates with various traditional cardiovascular risk factors, such as male gender, body mass index, waist circumference, LDL cholesterol, diabetes, smoking, hypertension, and family history of coronary artery disease [1]. Reactive hyperemia peripheral arterial tonometry (RH-PAT) can also serve as a non-invasive method for assessing peripheral vascular endothelial function and predicting cardiovascular events [2]. Studies have shown that RHI is independently associated with future cardiovascular events and can improve risk stratification [20], outperforming traditional Framingham risk scores in predicting cardiovascular events [21]. PAT offers numerous advantages over other tests, including being non-invasive, easy to operate, and producing reproducible results, making it a valuable tool for screening and prognosis.