A new in vitro measurement technique for small three-dimensional joint motion and its application to the sacroiliac joint. Med Eng Phys 1996 Sep;18(6):495-501
Date
09/01/1996Pubmed ID
8843405DOI
10.1016/1350-4533(95)00078-xScopus ID
2-s2.0-0030250948 (requires institutional sign-in at Scopus site) 6 CitationsAbstract
A new experimental technique for the measurement of three-dimensional (3-D), six degrees of freedom motion of a human joint is described. The apparatus consists of a solid cube and an orthogonal frame. Six spring-loaded linear variable differential transformers (LVDTs) are held by the frame in contact with three adjacent orthogonal surfaces of the cube. Three of the six LVDTs are positioned non-colinearly in contact with the first surface of the cube, two with the second surface, and one with the third surface. With the cube mounted on one of the moving bodies of a joint and the frame on the other one relative 3-D motion of the joint can be obtained from the six LVDT measurements based on the rigid body kinematics. An algorithm was developed to compute three Euler rotation angles and the 3-D translational components of a reference point on the body segment. The system was calibrated and applied to an in vitro study of sacroiliac joint motion. It has a rotational accuracy of 0.04 degree (with a S.D. of 0.07 degree) and a translational accuracy of 0.01 mm (with a S.D. of 0.01 mm). The possibility of adding a redundant seventh LVDT has also been explored and improvements in accuracy are reported. The main advantages of this technique are its compact size, accuracy, and low overall cost.
Author List
Wang M, Bryant JT, Dumas GAAuthor
Mei Wang PhD Associate Professor in the Orthopaedic Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Biomechanical PhenomenaBiomedical Engineering
Biophysics
Evaluation Studies as Topic
Humans
In Vitro Techniques
Joints
Motion
Movement
Sacroiliac Joint