1. Materials Science and Processing Technology
Biological properties of raw materials
Ordinary sheepskin bags: usually goat or sheep leather is used, and the focus is on the physical properties of the leather (such as softness, wear resistance) and the aesthetics of the surface texture. The leather screening standards are oriented towards commercial use, such as the integrity of the epidermis, uniformity of dyeing, etc.
Medical sheepskin bags: The raw materials must meet specific biological indicators. Taking Australian medical-grade sheepskin as an example, only wool from the back of Merino sheep with a density of ≥ 6,000 strands/cm2 is selected, and the fiber diameter must be controlled within the range of 18-22 microns to ensure that the fiber layer has ideal pressure buffering capacity.
Functionality-oriented processing technology
Conventional tanning process: Chrome tanning or vegetable tanning, which uses chemical treatment to enhance the stability of the leather, which may sacrifice some natural properties (such as breathability).
Medical-grade processing technology: It needs to pass ISO 13485 medical device management system certification and adopt chrome-free tanning process to achieve the biosafety requirements of high-temperature sterilization (steam treatment at 121°C for more than 30 minutes) while retaining the natural antimicrobial peptides (such as β-defensins) in the wool cuticle.
2. Biomechanics and clinical function
Differences in pressure distribution models
The design of ordinary sheepskin bags follows ergonomic principles, but lacks quantitative indicators.
Medical sheepskin bags need to pass a pressure sensor test: under a pressure of 30 mmHg (the critical value for bedsore risk), the surface contact area must increase by more than 40%, and the concentrated pressure must be converted into distributed stress through the three-dimensional mesh structure of elastic fibers.
Microenvironment regulation ability
Temperature and humidity management: The moisture absorption capacity of wool fibers in medical sheepskin bags can reach 35% (by weight), and the moisture is conducted to the surface for evaporation through the capillary effect, which can reduce the humidity of the skin surface by 30%-50% compared with ordinary sheepskin.
Gas exchange efficiency: The distance between medical-grade wool fibers forms an air layer of 0.5-1mm, and the oxygen diffusion rate reaches 0.25mL/(cm²·h), which is significantly higher than the 0.08mL/(cm²·h) of ordinary sheepskin.
3. Industry Standards and Testing and Certification
4. Clinical Application Data Reference
According to a 2022 clinical study in the Chinese Journal of Nursing:
In the group of bedridden patients using medical sheepskin bags (n=300), the incidence of stage II and above pressure sores was reduced to 2.1%, while the control group (ordinary sheepskin) was 11.7%.
The colony count test on the skin surface showed that the 24-hour colony growth of the medical group (4.3×10² CFU/cm²) was significantly lower than that of the ordinary group (2.1×10³ CFU/cm²).
5. Usage suggestions and precautions
Application scope of medical grade products
Recommended for patients with high-risk pressure ulcers with a Braden score ≤ 12
It needs to be used in conjunction with changing body positions every 2 hours and cannot completely replace basic care.
Material degradation identification
When the wool fiber is broken by ≥10% or the thickness is reduced by 30%, it should be replaced in time.
