Level 1 Diagnostics Endo-PAT is the leading medical device for Endopat Peripheral Arterial Tonenoninvasive endothelial function assessment. It is FDA-cleared, CE-marked and used in preeminent clinical and research institutions, major epidemiological population based studies (such as Framingham Heart Study) and pharmaceutical clinical phase studies in over 40 countries with thousands of tests performed every month.

PAT technology is a noninvasive window to the cardiovascular system and Autonomic Nervous System. Peripheral Arterial Tone (PAT) signal is a proprietary technology and is used for the non-invasive measuring of arterial tone changes in peripheral arterial beds. The PAT signal is measured from the fingertip by recording finger arterial pulsatile volume changes. Based on PAT technology, the noninvasive Endo-PAT system is comprised of a measurement apparatus that supports a pair of modified plethysmographic biosensors. The unique feature of the PAT bio-sensors is that they impart a uniform sub-diastolic pressure field to the distal two-thirds of the fingers including the tips. Applying the pressure in this way is extremely important as it prevents distal venous blood pooling that can induce a venoarteriolar vasoconstriction reflex.

Endo-PAT Process

Endo-PAT is based on noninvasive Peripheral Arterial Tone (PAT) signal technology. It measures endothelium-mediated changes in vascular tone using unique bio-sensors placed on the fingertips. These changes in arterial tone are elicited by creating a down-stream hyperemic response induced by a standard 5-minute occlusion of the feeding artery (using a standard blood pressure cuff on the patient’s least dominant arm).  When the cuff is released, the surge of blood flow causes an endothelium dependent Flow Mediated Dilatation (FMD).The dilatation, manifested as Reactive Hyperemia, is captured by Endo-PAT as an increase in the PAT Signal amplitude. A post-occlusion to pre-occlusion ratio is automatically calculated by the Endo-PAT software, providing the Endo-PAT index. Measurements from the contra-lateral arm are used to control for concurrent nonendothelial dependent changes in vascular tone. Endo-PAT tests can be carried out in the office, with patients positioned either sitting or supine. The test takes 15 minutes to complete, is very easy to perform, and is both operator and interpreter independent. Thermo-neutral, quiet surroundings are recommended.


  • FDA cleared and CE marked
  • Reliable and reproducible results
  • Noninvasive
  • Easy to use
  • Supports both clinical and research

Itamar Medical is the medical device company that develops, markets and sells diagnostic medical devices based on the PAT™ (Peripheral Arterial Tone) signal. Today, it is used clinically for early detection of heart disease, detection of obstructive sleep apnea, and erectile dysfunction. PAT-based products provide early-stage detection of disease and facilitate follow-up, improving patient care while reducing the overall cost of healthcare. PAT technology is incorporated in advanced research programs at institutes such as Framingham Heart Study, The Mayo Clinic, Harvard Medical School, Boston University, New England Medical Center, Yale University, Pittsburgh University Medical Center, Mount Sinai NY, Cedars-Sinai Medical Center, Johns Hopkins University, Emory University and many more.

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