Automatic tracking measurement system on human lumbar vertebral motion

An automated tracking system was developed to measure the flexion-extension motion of lumbar vertebrae using the algorithm of Sequential Important Resampling Particle Filter. In vitro validity was performed in 10 samples under digitized video fluoroscopy. Each sample was taken 2 full flexion-extension cycles under a special guide device in fixed speed, while the calibration model of lumbar vertebrae was fixed on a metal base. The trajectories are recorded by real-time depiction of the vertebral body with rigid fixation pens when the digitized video fluoroscopy collection is finished. A special system that can perform automatic tracking on the motion of lumbar vertebrae was developed. Reliability of the measurement was evaluated by a saw bone model experiment. In comparing with real-time motion recording, the correlation coefficient of test-retest and the accuracy were calculated, which showed satisfactory stability and consistency. The results suggested this new developed automatic tracking system could be a reliable tool to monitor the dynamic lumbar motion; to analyze the translation and rotational angle of vertebral from video-fluoroscopic images automatically and accurately. The proposed system may have a potential value in the evaluation of spinal medical application.