This is a pilot study. Maximum 30 subjects with a diabetic foot ulcer (DFU) or surgical foot wound will be consented in order to have 20 eligible subjects who will be enrolled and completed the study. Study duration will be three weeks. Patients will be consented and undergo debridement as standard of care at day 0. Ankle-Brachial Index (ABI), Monofilament Sensory Test and Vibration Perception Threshold(VPT) test will be performed only at day 0. Tissue samples will be taken at this visit during standard of care wound debridement and these tissue samples of the wound would normally be removed as part of routine debridement. These tissue samples of the wound will be used for gene expression and bacterial analysis(research). The patient will then receive topical oxygen therapy using the Transcutaneous O2 device (research) with moist wound dressings for 21 days. Moist wound dressings are used as standard of care. Treatment will be initiated during Screening/Baseline visit(day 0) after routine wound debridement, and patient will receive instructions for home use of the device. The patient will be seen for routine wound debridement at days 7, 14, and 21 with a study window of 5 days., Digital photos of the wound, and vascular evaluations (Transcutaneous oxygen measurements and Hyperspectral imaging. will be performed at each study visit(research). Tissue samples will be taken during standard of care wound debridement at every study visit. Results of the data analysis from this project will be used to inform the design of a larger randomized clinical trial.

Patients seen at the University of Texas (UT) Southwestern Wound Clinic with a diabetic foot wound will be identified, consented, and screened for the study. Upon signing consent, patients will be assigned a unique screening number. The screening number given to the first patient will be 01 and increasing sequentially with each subject screened. Screened subjects will be entered onto a screening log. Once a number is assigned it cannot be re-assigned to another subject.

At Day 0, a vascular evaluation including ABI, Sensilase, Transcutaneous oxygen measurements, and hyperspectral imaging will be performed. Monofilament Sensory Test and Vibration Perception Threshold(VPT) test will also be performed at day 0.Patients will undergo standard of care wound debridement. Tissue samples will be taken routinely as standard of care. A wound assessment will be performed, including the debridement as standard of care, wound measurements, and digital photos. Gene expression and bacterial analysis will be performed on tissue samples. After tests are performed, patient will receive topical oxygen therapy using the Transcutaneous O2 device with moist wound dressings. Moist wound dressings are used as standard of care. Patient will receive instructions to continue treatment at home.

Patient will return for an appointment at days 7, 14, and 21, where vascular assessment (Sensilase, Transcutaneous oxygen measurements, Hyperspectral imaging) ,wound assessment (wound measurements, digital photos and acetate tracings) and tissue sampling will be performed following standard of care debridement, Patient will cease topical oxygen treatment at day 21, and study will be concluded.

Inclusion Criteria:

• Male or female subjects of all races and ethnicities, age 18-89
• Diagnosis of diabetes mellitus
• Has a diabetic foot ulcer

Exclusion Criteria:

• End-stage renal disease (ESRD)
• Has untreated foot ulcer at time of study
• HIV, hepatitis, autoimmune disease, Systemic lupus erythematous (SLE), Raynaud's disease
• Ankle-Brachial Index (ABI) < 0.4
• Unable or unwilling to provide informed consent

21 days