This study aims to develop a low-cost, marker-free intelligent wound assessment system that can analyze wound photos taken with a standard smartphone. By comparing wound images over time, the system will generate a quantifiable Wound Progression Index (WPI) to provide objective feedback on whether a wound is improving, stable, or worsening. The long-term goal is to support early detection of wound deterioration and improve wound care in both clinical and home settings.

Participants receiving routine wound care will undergo standardized wound photography during dressing changes. Longitudinal wound images will be analyzed to develop and validate a marker-free wound progression assessment method. No treatment assignment or modification of standard clinical care will occur.

Inclusion Criteria:

• (1) Presence of a hard-to-heal wound that has remained unhealed for more than one month. (2)The wound can be photographed according to the standardized imaging protocol. (3)The participant was aged 18 years or older and provided informed consent personally or via a legally authorized representative, with a signed informed consent form.

Exclusion Criteria:

• Wounds whose margins could not be fully included within the imaging field.

Adult patients with hard-to-heal wounds located on body sites that can be fully captured within a single standardized image.

wound images

starting 6 months after publication

Requests must include a structured research proposal specifying the objectives, analysis plan, and data required. All requests will be reviewed by the corresponding investigator and the study's principal research team to ensure scientific validity, ethical compliance, and protection of participant confidentiality. Additional approval from an institutional review board or ethics committee may be required depending on the nature of the proposed analysis.