Large segmental mandible bone defects still represent a challenge for endogenous regeneration. Despite the bone's capacity to heal in many clinical situations, bone defects over a critical size do not heal spontaneously. An emerging treatment of critically sized mandibular defects is the implantation of individually manufactured scaffolds consisting of biodegradable magnesium alloys. Biomedical engineers faced the challenge of developing a scaffold structure that not only provides sufficient stability, but also stimulates and promotes bone growth while considering the degradation of the magnesium alloy. The porosity of the scaffold must also support bone ingrowth and neovascularization. For an optimal design and subsequent structural optimization knowledge of external load cases is essential. However, currently the muscle and joint forces of the mandible cannot be measured directly. The aim of our study was therefore the development of a parametric human mandible model to determine the relevant boundary conditions for the subsequent structural optimization of individual jawbone implants. Using a model-based approach, determining the essential external load of the mandible as a function of the age and sex of a patient individually and the realistic simulation of the mechanical stress for patient-specific loads and anatomies has been realized. The developed model is successfully validated by evaluating the deformations and stresses of the lower jaw of a possible patient and comparing them with the results of dental research. Based on the results of the modelling, in a subsequent optimization process section forces at the interface between the bone tissue and jawbone implant can be determined and used to optimize the design of the jawbone implant.

The development of patient-specific medical systems poses challenges for requirements engineering and their traceable integration into system models, as regulatory frameworks require transparent and traceable links between stakeholder needs and product requirements. Document-based approaches lack the formal structure required to derive verifiable product requirements and integrate patient-individual parameters into testing processes. This study investigates how Model-Based Systems Engineering (MBSE) can formalize user needs, user requirements, and patient context parameters to enable a traceable, model-based testing of patient-specific systems. A SysML-based formalization approach is developed that extends the motego method. New stereotypes for user needs and user requirements are introduced and linked via SysML relations to stakeholders, use scenarios, and product requirements. A patient context model is proposed to represent patient-individual parameters and integrate them into a model-based test framework. The approach is demonstrated using an exemplary use case by instantiating representative user needs, user requirements, and patient context parameters and linking them to functions, solutions, and domain model elements within the test framework. An exemplary use case demonstrates the integration and transfer of context parameters. The results show a traceable chain between stakeholders and product requirements, as well as the consistent transfer of context parameters into domain model elements. The simulation is used exclusively as an executable component to demonstrate data integration and model consistency; no validation of physical accuracy is performed.

Technical folding systems are rigid, three-dimensional surface structures that can be folded at their joints. Due to their foldable structure, technical folding systems can produce lightweight structures that have a high load-bearing capacity and can also flexibly change their shape. In order to develop products with technical folding in a function-oriented product development process, a folding principle must be defined that realises the individual functions. Since there is hardly any expert knowledge on technical folding, in general, and on the use of the technical folding principle in particular, technical folding is not very widespread despite its promising properties. Therefore, there is a need for a software-supported evaluation of whether functions can be realised by the principle of technical folding. The software-supported applicability evaluation (EvalTech) developed here is based on case-based reasoning methods, as these can artificially simulate evaluations based on expert knowledge. The expert knowledge used for the evaluation includes functions, function structures and properties of known technical folding systems, which are compared with functions and function structures of the development task. EvalTech was successfully used in the development and realisation of a large-scale foldable cover for industrial robots.