The Effect of Natrox® Oxygen Wound Therapy on the Healing Rate of Chronic Diabetic Foot Ulcers

Exclusion Criteria

• •1. Subject has a known life expectancy of \< 1 year
• •2. Subject or caregiver is unable to manage the Natrox® device (charge and change batteries daily)
• •3. Subject has ulcers that are completely necrotic or if the clinician feels it is clinically necessary to cover the wound surface in gel or creams that would prevent the transmission of oxygen to the wound surface.
• •4. Subject has major uncontrolled medical disorders such as serious cardiovascular, renal, liver or pulmonary disease, lupus, palliative care or sickle cell anemia.
• •5. Subject currently being treated for an active malignant disease or subjects with history of malignancy within the wound.
• •6. The Subject has other concurrent conditions that in the opinion of the Investigator may compromise subject safety
• •7. Known contraindications for the Natrox system
• •8. Known allergies to any of the Natrox system components
• •9. Concurrent participation in another clinical trial that involves an investigational drug or device that would interfere with this study.
• •10. Index ulcer has reduced in area by 20% or more after 2 weeks of standard of care from the first screening visit (S1) to the TV1/randomization visit.
• •11. Subject is pregnant or breast feeding.
• •12. Subjects with a history of more than two weeks treatment with immunosuppressants (including systemic corticosteroids \>10mg daily dose), cytotoxic chemotherapy, or application of topical steroids to the ulcer surface within one month prior to first Screening Visit, or who receive such medications during the screening period, or who are anticipated to require such medications during the course of the study.
• •13. Index ulcer has been previously treated with tissue engineered materials (e.g. Apligraf® or Dermagraft®) or other scaffold materials (e.g. Oasis, Matristem) within the last 30 days preceding the first treatment visit.
• •14. Affected extremity requiring hyperbaric oxygen during the trial or within 2 weeks of treatment visit 1.
• •15. Known HbA1C \>12%
• •16. An ulcer that has visible signs of improvement in the four weeks prior to randomization defined objectively as a 40% reduction in surface area in the four weeks prior to enrollment.
• •17. An ulcer that has healed by more than 20% in the 2 weeks prior to screening: "historical" run-in period.