Rib cage recreation: Towards realistic neonatal manikin construction using MRI scanning and 3D printing

Within our research, the human body plays a central role. The human body is one of the most visually fascinating shapes, but our research goes further. We focus on the dynamic aspects of the body regarding interaction. Within this paper, we focus on the creation of manikins for the training of chest compressions, which is an essential procedure during cardiopulmonary resuscitation (CPR). We expect that the same techniques can be deployed for manikins in different applicational fields, such as fashion dummies, toys, and artistic installations. Within medical simulation, it is important that manikins have realistic anatomical and physiological properties. By embedding these properties, a more realistic tactile experience can be created. From our findings, we conclude that additive manufacturing materials have a broad mechanical stiffness range, with the potential to mimic that of the neonatal rib cage. Vision and Introduction CPR is an important procedure to ensure survival of patients suffering from cardiac arrest. One part of this procedure is the compressions of the chest to manually take over the function of the heart. To receive adequate training on how to perform CPR we find that it is of importance that the manikins used during training provide realistic anatomical and physiological behaviour to the trainees. The benefits of realistic tactile experience are that it can enhance effective learning[1]. For the training of chest compressions, a thorax with embedded rib cage is essential for a realistic tactile experience of chest deformation. Recently we turned our attention from adults to newborns and began collaborating with neonatologists. The training of performing chest compressions on a newborn is crucial. Newborn tissues are of a much lower density than those of the adult[2], and therefore require more care when being compressed. Realising this manikin realism in organic, tactile experience can only be obtained through additive manufacturing, or 3D printing as it is more commonly known, not through traditional mass manufacturing techniques such as injection molding. Although injection molding has since the discovery of plastics been the main production method for user products, it is difficult for this technique to meet the demand of mixed material properties providing differing movement and flexibility throughout the material. As the human body is constructed out of multiple tissue types, it is only possible to achieve the desired material complexity through 3D printing, where multiple material types can be mixed, and printing densities can be varied. Secondly, with 3D printing we free ourselves from the mold making process, which is time-consuming and expensive. Currently, there are no simulator manikins on the market which provide a realistic tactile experience relating to newborn chest deformation. Within this paper, we will show our explorations to find whether it is possible to recreate realistic neonatal rib cages with the materials available to us in 3D printing. First, we will explain our reconstruction method of the rib cage, using MRI imaging and additive manufacturing. Next, we will show the methods and results of our vertical force-deformation testing performed upon five rib cages following chest compression depth guidelines[3].