Abstract

This contribution deals with the development of a system based modelling approach for anatomic joints. Modelling and simulation in the field of biomechanics is a very important method to analyse the dynamic behaviour of the human body. Understanding the influence of the individual parts of the musculoskeletal system is necessary for the analysis and treatment of diseases. Furthermore, mathematical models of parts of the human body are indispensable in the development of prostheses. The engineering progress in the last decades in the field of prostheses lead to an enormous enhancement of life quality for disabled people. Nowadays, wearing a prosthesis does not restrict daily life and normal habits so much. Modern leg prostheses adapt to the gait cycle by changing the damping of the knee as humans do it automatically. This technology reduces the risk of falling and extends activities with prostheses as doing sports and walking on uneven ground. Sensoring the knee angle and ground contact of the heel gives the possibility to control the change of the swung into the stance phase and vice versa via a micro- processor in the prosthesis. For example this technology is used in prostheses developed by ottobock, a well known manufacturer of healthcare systems. Among several methods exist to model a biomechanical system, two approaches to describe these systems are most common, Partial differential equations and Multibody modelling. Modelling a biomechanical system with PDEs is used to compute the strains and stresses in the components during small movements. Multibody models are used to describe the kinematics of the underlying system under gross movements. These two approaches describe the biomechanical system on a microscopic and macroscopic level, respectively. In order to formulate a PDE model a detailed knowledge about the system is required which is not every time available. The main part of this contribution is the integration of a biomechanical system in a system simulation loop circuit and not the formulation of an additional biomechanical model for a human joint. This gives the opportunity to improve the technology used in prostheses and the research in the field of biomechanics of human joints.