The Medical Simulation Group at the Institute of Systems Science in Singapore has set up a project in cooperation with the Defence Medical Research Institute to develop a biomechanical model-based simulation system which is capable of recreating the environment in order to analyse neck injuries under various circumstances. The virtual reality system, called SeeImpact, comprises a model of the human head and cervical spine including the possibility to generate bone stresses and muscular forces. The research team wants the computer program to serve both as analytical and predictive tool for the end user. Extension and modification of the simulation model for related applications are being envisaged.
The SeeImpact project merges technologies in engineering, computer science and medicine. To begin with, the construction of the cervical spine model has to correspond with the specific characteristics of structural and dynamic properties relevant to the local population. The various parameters have to be defined according to different methods such as experimental testing or the use of values in literature. The actual development of the biomechanical model initially will lead to a simple Newtonian multi-rigid-body system integrating all muscle structures and individual vertebrae. The deformation of vertebrae and intervertebral discs will not yet be taken in account in the first stage. Reaction force analysis will be computed only as singular points.
In a second phase, deformation and stress distributions over a surface in opposition to a single point will be measured by means of finite element analysis. The prediction capabilities will be improved as the team proceeds to a more complex model which incorporates material properties and non-linearity capacity. The final step will result in an authentic virtual reality system providing a user-friendly interface allowing to read or change the inputs in an interactive way. The outcomes will be displayed both numerically and graphically.
The user disposes of three windows. On the main one, the object is viewed in skeletal or anatomical form with possible rotation or scaling. Muscles can be attached and adjusted. The second window is a graph window showing the changes over time. The control window contains buttons and sliders for the selection of various parameters. Further refinement and validation of the system will allow injury prevention in the automotive industry where crash scenarios are tried out, as well as permit implementation in commercial aircraft industries. Detailed ergonomic analysis for load carriage and workstation design by means of spinal models integrated in complete body mannequins constitutes yet another application.
Medical simulators such as the SeeImpact model are offering a significant potential for reducing the health care costs since they help to improve human performance and to decrease design and testing times for new equipment. The Medical Simulation Group in Singapore has more news in store for you on the web site of the Institute of Systems Science.