To assess the efficacy of a pressure ulcer treatment mattress, the P400 mattress, in the treatment of multiple Stage II or one or more large Stage III or IV pressure ulcers in the home care and extended care (nursing home) environment.

Subjects will be recruited from those presenting to the wound clinic and meet the inclusion criteria. A total of 30 evaluable subjects will be recruited for this study from up to 2 wound care clinics /home health agencies (15 in Home Care and 15 in Extended Care). Subjects will be followed by weekly wound assessments for a period of 12 weeks or until their wounds heal. The outcome measurement is the rate of healing over the 12 week period.

Inclusion Criteria:

1. Subject has multiple Stage II pressure ulcers or at least one Stage III or IV pressure ulcer(s) (as per National Pressure Ulcer Advisory Panel Staging guidelines) located either on the trunk or pelvis (which would include trochanter and ischial ulcers ) having a clean wound bed of less than or equal to 25% necrotic tissue at the base of the pressure ulcer.
2. Subjects may have heel ulcers, however these ulcers may not be considered a target study ulcer.
3. Subject, or legally authorized representative is able to provide informed consent
4. Subject weighs between 70 and 350 pounds
5. Subject's nutritional status is thought to be adequate to support wound healing
6. Subject qualifies for a Group 2 support surface (Target study ulcer must be at least 8 cm^2 in area to qualify)

Exclusion Criteria:

1. Subject's target ulcer is unstageable due to eschar or necrosis or a suspected Deep Tissue Injury may be located at the base of the wound.
2. Subject has unresolved systemic infection, or pressure ulcer infection, or a history of osteomyelitis, or greater than 25% eschar or necrotic tissue present in the wound bed.
3. Patient has already been enrolled in this study
4. Patient has a recent history of non-compliance with pressure ulcer offloading, repositioning, or other areas of the treatment care plan, which would jeopardize wound healing if continued.
5. Care plan goals are palliative

Patients with multiple Stage II or at least one Stage III or IV pressure ulcer having less than or equal to 25% necrotic tissue present in the pressure ulcer at the time of placement.

Small study with no comparative arm.