Chronic wounds affect many patients, with no downward trend in recent decades. This is a significant economic and social issue, and this condition has an impact on functional disabilities and quality of life, especially among the elderly. Diagnosis is essentially clinical, and there are many causes, but 90% of leg ulcers, for example, are primarily vascular in origin. There are wounds of traumatic, post-operative, and vascular origin, as well as pressure sores. The main purpose of invasive tests is to objectively determine the cause (arterial damage) or to check for underlying osteitis. Chronic wounds are usually infected or colonized by bacteria from the skin and digestive flora. There is no indication for antibiotic therapy in the treatment of wounds. Nursing staff play an important role in therapeutic management, which must be carried out in harmony with other healthcare professionals, such as general practitioners and specialists. This management has two main goals: to accelerate the epidermalization of chronic wounds, or even their healing, and to limit local and general complications, the recurrence of which remains the most difficult to control. There are many types of healing dressings available, adapted to each type of ulceration: fibrinous, necrotic, superinfected, etc.

Nevertheless, innovative solutions can accelerate healing, thereby reducing hospital stays, disabilities associated with chronic wounds, and complications such as skin-related septicemia. Research efforts may focus on the use of growth factors, for example, for old or stubborn forms of the disease, despite proper medical treatment, or on any other innovative technique.

The properties of cold plasma appear to be suitable for the treatment of chronic wounds, as has been demonstrated in cell models, animal models, and with argon plasma in several countries around the world on an experimental basis in humans.

The GREMI in Orléans has acquired internationally recognized expertise in the technique of cold helium plasma. The combination of this applied research laboratory and the Infectious Diseases Department of the Orléans University Hospital has led to the development of relationships that have resulted in the proposal to conduct this study, based in its first phase on the evaluation of the medical device's tolerance.

Inclusion Criteria:

1. Men or women.
2. Aged 18 years or older.
3. Chronic wound or ulceration.
4. Wound measuring 5 to 100 cm² of arterial or venous origin.
5. Evolution > 4 weeks.
6. With less than 30% necrosis.
7. Able to give informed written consent.
8. Blood pregnancy test for women of childbearing age.

Exclusion Criteria:

1. Tumor wounds
2. Dialysis
3. Patients requiring surgical revascularization
4. Severe heart failure (NYHA III-IV) or acute myocardial infarction.
5. Wounds or ulcers located less than 10 cm from the patient's airways and respiratory tract
6. Severe renal failure defined as creatinine clearance <20 mL/min calculated according to the MDRD
7. Patients with severe hepatic impairment (class C) according to the Child Pugh score
8. Unstable liver disease (defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminemia, esophageal or gastric varices, or persistent jaundice), cirrhosis, known biliary abnormality.
9. Active malignant tumor
10. Patients who, in the investigator's opinion, are at significant risk of suicide
11. Any pre-existing physical or mental condition that may interfere with the patient's ability to comply with the administration schedule and/or protocol assessments, or that may compromise the patient's safety.
12. Persons covered by Articles L.1121-5 to L.1121-8 and L.1122-1-2 of the Public Health Code (including minors and protected adults)
13. Protected person (under guardianship or curatorship)
14. Person under judicial protection
15. Persons deprived of their liberty
16. Persons not affiliated with a social security system
17. Women who are pregnant or breastfeeding, or who plan to become pregnant or breastfeed during the study.
18. Patients participating in another clinical trial evaluating a treatment
19. Allergy to the dressings used in the trial