Intermittent Negative Pressure; Impact on Peripheral Artery Disease and Intermittent Claudication

Inclusion Criteria: * Male or female outpatients, age greater or equal 18 years * Stable evidence based pAVK therapy for at least 3 months * Ability to perform a treadmill test * Confirmation of clinical diagnosis of PAD as objective evidence of Fontaine stage IIb PAD i.e.: * Reduced ankle systolic blood pressure (ABI \<0.9) on target leg * Pain free walking distance \< 200 m in standardized walking test (initial claudication distance (ICD)) * Completion of at least two treadmill tests within a time interval of greater or equal to 1 week prior to randomisation. Maximum change in claudication should not exceed a predefined threshold (\<25% for the absolute claudication distance (ACD)). * Intermittent claudication lasting for at least 3 months * Stable smoking habits for at least 3 months prior to inclusion * Signed Informed Consent Exclusion Criteria: * PAOD-patients with critical limb ischemia (CLI), equivalent to EMA's or Fontaine's PAOD-stages III and IV * Any kind of revascularization (endovascular, surgical) in the iliac or other leg arteries within 3 months prior to Visit 1 * Patients with polyneuropathy * Other illnesses limiting exercise capacity (angina pectoris, heart failure, respiratory disease, orthopedic disease, neurological disorders) * Use of confounding medications within the last 4 weeks prior the Visit 1 e.g. vasoactive compounds like Cilostazol or Naftidrofuryl * Uncontrolled hypertension (\> 180/95 mmHg) or hypotension (supine \< 100 mmHg) * Severe anemia * Pregnancy or lactation period * Woman with childbearing potential without an effective contraceptive method (effective contraception method: hormonal contraceptive, hormonal vaginal devices or injections with prolonged release; an intrauterine device, or a barrier method of contraception such as condom or occlusive cap with spermicide (foam/gel/film/cream/suppository) * Planned surgical intervention requiring hospitalization during the clinical trial * Previous inclusion in the present clinical trial or parallel participation in other clinical trials (up to 8 weeks before Visit 1) * Incapability of understanding nature, meaning and consequences of the clinical trial * Patient unable to read and or write * Patients in custody by juridical or official order * Patients, who are members of the staff of the trial centre, staff of the sponsor or involved Clinical Research Organizations (CRO's), the investigator him-/herself or close relatives of the investigator * Patients unable to don or doff the FlowOx device (either themselves or with assistance from a helper). * Diagnosed acute deep vein thrombosis * Systemic infection * Alcohol disease or drug abuse * Malignant disease