To evaluate the efficacy and clinical satisfaction of topical oxygen therapy (LOT) in chronic wounds (including patients and medical staff), and explore its possible mechanism.

A multi-center open randomized controlled study was conducted. A total of 240 subjects were expected to be accepted. Patients receiving normative wound treatment received cyclic topical oxygen therapy, not excluding the treatment of other diseases.

After signing the informed consent, the patients were randomly divided into the treatment group and the control group. The total treatment time was 12 weeks or the wound healed completely. The enrollment examination included lower limb arteriovenous examination (including B-mode ultrasound, ankle-brachial index), and other related necessary examinations (such as biopsy excluding malignant tumors; blood routine, bacterial culture excluding wound infection; vibration area detection excludes peripheral neuropathy). Relevant examinations and records were made at each time point, including pre-admission and weekly follow-up days. Wound area measurement, image data collection, wound analysis, secretion detection, patient pain score and satisfaction survey, medical staff evaluation were required at each time point. Every patient in the group and the follow-up day should be treated according to the guidance of the doctor according to the type of wound, including wet wound treatment, debridement, decompression, stress treatment and so on.

Inclusion Criteria:

①18 years old or older, regardless of gender;

②It was clinically diagnosed as chronic lower limb wound, which was located below the thigh.

Patients who received mainly etiological treatment, wet dressing change and necessary decompression for more than 2 weeks had no obvious wound healing tendency;

③Understanding the experimental conditions, Patients are willing to participate in and cooperate with the experimental treatment, and sign the informed consent.

Exclusion Criteria:

1. Edema of lower extremity caused by cardiac insufficiency;
2. patients with venous thrombosis of lower extremity;
3. Diabetics with poor blood glucose control: FBS>=8mmol/L; Blood glucose 2h after meal>=10.0mmol/L; HbA1c >= 9%
4. Participated in similar clinical trials in the last three months; Patients with lower extremity arterial occlusion requiring lower extremity vascular surgery;
5. Patients with wound infection requiring systemic antibiotic therapy;
6. Dry scab or necrotic tissue covered more than 50% of the wound, and was not suitable or refused to accept debridement treatment.
7. Immunodeficiency patients
8. Patients with malignant change of wound or with malignant lesions
9. Patients with wound area greater than 10 cm*10 cm;
10. the wound is deep into sclerotin,articular cavity and body cavity;
11. The wound with sinus tract;
12. patients with serious hepatic dysfunction and malnutrition;
13. Patients with mental or other problems and unable to self-manage equipment
14. Treatment of patients with poor compliance.
15. The researchers think there are other reasons which the patients cannot participate in this clinical trial.

We will share our study protocol and results without the patients' privacy.

After our paper's publication.