Assessment of a hydrodynamic model of Whiplash induced transient pressure in the spinal canal - Using in-vivo Whiplash simulation data

Abstract

During rear-end collisions, the occupant’s body is accelerated and pushed forward by the seatback while the unsupported head lags behind, resulting in the Whiplash motion to the cervical spine. Whiplash injuries are one of the most common injuries in rear impacts, that often cause pain and can cause symptoms such as dizziness, headaches, vision disorder, and neurological and upper extremities. During the rapid Whiplash motion in the neck, blood redistribution in the internal vertebral venous plexus will compensate for the rapid volume change inside the spinal canal, and as a result impulsive pressure transients are induced. It has been hypothesized that the transient pressure changes can result in injurious loading on the cervical dorsal root ganglia, This may explain the mechanism of injury and the source of the symptoms that whiplash injury victims suffer from. This project aimed to analyze high speed X-ray movies of porcine subjects in in-vivo whiplash experiments of varying severity, to digitize vertebral motion of the neck during the tests, and to evaluate the accuracy of a previously developed MATLAB-Simulink hydrodynamic model of transient pressure changes in Whiplash motion using the data from the mentioned experiments. Overall, the simulated results are in the same order of magnitude compared to the experimental readings, but the timing seems to have a delay. The raw X-ray movies had a limited noise-signal ratio due to the relatively thick soft-tissue layer in the porcine neck that resulted in a limited contrast in the video frames. There is potential for more accurate tracking of the vertebral angular motion with modified signal filtering or possibly by applying machine learning techniques for improved pattern recognition in the video frames.