Unique thermal-comfort design for 3D printed orthopaedic casts

News - 25 October 2017

Researchers of the faculty of IDE (TU Delft) and Boston University have developed a new way to create 3D printed, personalised orthopaedic casts. For the first time, the design takes into account both mechanical stability and thermal comfort. The researchers will present this innovative work in the 2017 ACM Symposium on User Interface Software and Technology in Quebec City.

Anyone who has broken a bone often gets a plaster band that provides support and protection so that the bone can heal. Traditional gypsum bonds, however, are often large, bulky and difficult to apply. Because they barely breathe, the skin is often overheated and irritated. Taking a shower too is a difficult task because these plaster connections are not well-suited to water.

The researchers created a 3D printed orthopaedic cast that offers the same support and protection, but takes into account the heat sensitivity of specific areas on the skin. In places where the skin has a high heat sensitivity, air circulation has to be improved in order to stay comfortable, without losing the strength of the cast.  

The heat sensitivity of the skin on different areas is different for everyone. Therefore, making a personalised 3D-printed cast starts with a 3D scan of the body part that needs to be protected. After that follows an analysis of the skin's heat sensitivity by an infrared camera. This data is processed into a 3D printable net-like structure, in which the size and distribution of the air holes are directly related to the skin sensitivity of the skin in those places. When calculating the structure with the air holes, the forces acting on it are also taken into account. Areas with high heat sensitivity and thus large air holes become slightly thicker, making the cast strong enough in all areas. The result is a light weight, comfortable and waterproof cast to optimally support a damaged body part. 

"I think this is the first result in this area that takes thermal comfort into account," says Professor Charlie Wang of the faculty of IDE. 'These personalised plaster connections from the 3D printer provide much more natural support, which offers patients more comfort through optimal air circulation. This can also help the healing process. However, we are still in the prototype phase, testing in a medical environment must still happen. '

Xiaoting Zhang, Guoxin Fang, Chengkai Dai, Jouke Verlinden, Jun Wu, Emily Whiting, and Charlie Wang, ‘Thermal-Comfort Design of Personalized Casts’, ACM Symposium on User Interface Software and Technology (UIST), 2017