The cushion has an auxetic structure that adapts to individual pressure zones based on the person's body data. Thanks to optimum pressure distribution, it reduces the risk of pressure sores (decubitus ulcers) and offers greater comfort during prolonged sitting.
Pressure sores are a common consequence of spinal cord injury, particularly in paraplegia, where immobility and reduced sensation significantly increase the risk. The wheelchair seat cushion plays a crucial role, serving not only as a barrier between the user and their wheelchair, but also between comfort and discomfort, skin vitality and irritation.
Pressure measurements show the individual pressure distribution when sitting. Particular attention is paid to the pressure points caused by the two ischial tuberosities, the coccyx and the sacrum.
A wheelchair cushion isn't universally applicable, it should be customized for each individual user. By inputting a user's seat pressure map, seat area dimensions, and weight, the predetermined geometry is adjusted, resulting in a cushion that fits the user perfectly and redistributes the pressure evenly.
The thickness of the cell structure determines the density and thus influences the hardness of individual sections of the cushion. The individual pressure adjustment ensures optimal contact and the largest possible pressure distribution surface. In addition, the individual firmness areas promote ideal immersion of the user in the cushion, which improves stability, posture and pelvic alignment.
Due to its open structure, the pillow provides a suitable microclimate that offers the user improved air circulation and breathability, reducing heat build-up and moisture. In case of incontinence, it is easily washable. Compared to gel or air cushions, it is low maintenance as it does not need to be adjusted by the user, therefore also reducing the risk of misuse.
Compared to foam, air or gel, the advantage of an additively manufactured auxetic cushion is that it can produce precisely controllable geometries with different densities, which significantly improves the cushioning properties
The contraction properties of auxetic structures are superior in terms of energy absorption and damping. This is particularly beneficial for wheelchair users who may be subjected to bumps, as it helps to minimize shock and vibration. Compared to foam, auxetic structures are more durable due to their uniform deformation and improved tensile strength under long-term loading.
The contraction properties of auxetic structures are superior in terms of energy absorption and damping. This is particularly beneficial for wheelchair users who may be subjected to bumps, as it helps to minimize shock and vibration. Compared to foam, auxetic structures are more durable due to their uniform deformation and improved tensile strength under long-term loading.
Emma Johann
This project was developed together with Emma Johann as an Applied Research Project during her internship.
The project was only possible due to the constant exchange with medical experts from various institutions. Special thanks to the Department for Spinal Cord Injuries at the BG Klinikum Unfallkrankenhaus Berlin.
