Research objectives and content
The goal of the project is to design, build and validate a
six-degree-of-f_edom mechanism for biofidelic test-bed simulation of inter-vertebral motion, employing standard six-degree-offreedom parallel platform design and control techniques. Hereby, loads and deformations are to be generated by a set of pneumatic legs joining the lower (caudal) vertebra (the 'base') with the upper (cephalic) vertebra (the 'platform'), respectively. Forces at the legs are computed by a suitable feed back control law determining pneumatic cylinder chamber pressures as a function of position of the platform and biologic parameters. As a result, a virtual cervical spine mechanism is produced that, although built differently than the natural spine, behaves physically in the same way, i.e., yielding the same stiffness properties as the real system. This makes it possible to adapt the mechanism behaviour to different test objects and load situations, allowing the analyst (physician, medical researcher, surgeon, or biomechanics engineer) to assess effects of therapeutic or surgical treatment prior to its application to the patient. Moreover, it may serve as a powerful tool for educational purposes, and as a highresolution test apparatus for in vitro accurate measuring of biological parameters of spinal units under controlled motion/load conditions.
Training content (objective, benefit and expected impact)
The expected training benefit would be in the areas of (1) biomechanics, (2) mechanism design, (3) optimisation, (4) advanced multibody simulation, (5) object-oriented programming, and (6) control of mechatronic systems. Additionally, the creation of the targeted virtual cervical spine mechanism would endow physicians and educational instructors with a powerful tool for assessing inter-vertebral motion under physiognomic loads. Links with industry / industrial relevance (22)
Understanding of inter-vertebral motion and its implications in injury and spine disease is of paramount interest in vehicle industry, insurance and medical industry. Involvement of the project with industry will take place through its link with the two EC contracts 'Whiplash Prevention System (WPS)' (Contract No BRST-CT97-5162(DG12-CZJU)) and 'Whiplash' (Contract No BRPR-CT96-0221 (DG12-RSMT)) currently conducted at the Institute of Mechanics in co-operation with Delphi Automotive Systems, GIE PSA Peugeot Citroen. Fiat, Volkswagen, and TNO.