Research On The Evaluation Method Of Human Body Balance Function Based On 3D Somatosensory Camera

Objective: The purpose of this study is to test the accuracy of Kinect v2.0 in capturing 25 joints of human body through the simultaneous measurement and comparison of Kinect v2.0 and biplane X-ray film of the whole body;to test the reliability between the systems through the simultaneous measurement and comparison of Kinect v2.0 and vicon and Kistler force measuring platform of optical three-dimensional motion capture system,and to explore the possibility of Kinect v2.0 in capturing 25 joints of human body V2.0 system based balance function evaluation method.Methods: In this study,five healthy adults were recruited for Kinect v2.0 and whole body biplane X-ray synchronous measurement,ICP algorithm was used to register and calculate the shortest distance between corresponding joint points to verify the accuracy of Kinect v2.0 for human joint coordinate capture;14 healthy adult men were recruited,Kinect v2.0 was used Vicon system and Kistler dynamometer were used to test the static balance function(open eyes bipedal stand,closed eyes bipedal stand,open eyes bipedal stand,closed eyes bipedal stand)and dynamic balance function(multi-directional extension and test).The indexes such as the length of center of gravity swing,the speed of center of gravity swing,the amplitude of center of gravity swing and the area of center of gravity swing were obtained,and the intra group correlation coefficient was calculated.Results: After ICP algorithm iterative registration,the average distance of most joints of Kinect v2.0 system and the whole body biplane X-ray corresponding to 17 joints is within 30 mm,of which the average distance of joints of limbs is between 9.7-24.7mm,and the average distance of joints of trunk is between 21.2-78.7.Compared with vicon,most of the ICC of the test results of open eyes bipedal standing is 0.657-0.902;the ICC of the test results of closed eyes bipedal standing is 0.572-0.901;the ICC of the test results of open eyes bipedal standing is 0.436-0.892;the ICC of the test results of closed eyes bipedal standing is 0.439-0.882,and there is significant consistency and similarity between the two groups.Compared with the Kistler dynamometer,all ICC indexes of Kistler are greater than 0.4,and the results have significant consistency and correlation.The ICC variation range of the results of the multi-directional extension test on each plane is mainly between 0.547-0.863,and there is significant consistency and similarity between the two groups of test results Conclusion: The results of this study show that Kinect v2.0 has good accuracy after registration with the whole body biplane X-ray film;Kinect v2.0 is consistent with the balance evaluation results of Vicon system and Kistler force plate,and the reliability between the systems is good.