Prospective interventional study. The aim is to analyze the effect of usual ongoing treatments over microvascular cutaneous response to galvanic current applications (CIV: current induced vasodilatation) with tissue vitality (TiVi) system on the forearm of subjects referred for ultrasound investigations due to suspicion of peripheral disease. Hypothesis is that the use of aspirin (even at low dose) abolishes the response.

This test could make it possible to detect the functional effects of low dose aspirin without using biological tests. A routine clinical application could be to use this CIV to verify adherence to aspirin.

At admission eligible patients are proposed to participate. Written consent is signed after complete oral and written explanation of the protocol is signed.

No register of non-included patients will be kept. In included patients, in parallel to the routine ultrasound investigation for which the patient is referred, microvascular investigation will be performed as explained later in arm description.

Usual ongoing treatments are obtained by history and recorded. The end of the visit is the end of the participation of the subjects.

Inclusion Criteria:

• subjects referred for investigation of peripheral arterial disease.
• Affiliation to the French National healthcare system
• French speaking patients
• Ability to stand still for half a minute.

Exclusion Criteria:

• pregnancy
• inability to understand the study goal
• Patients protected by decision of law