[A Three-dimensional Goniometer Linkage System for the Analysis of Movement with Six Degrees of Freedom]

A measuring system for the determination of the six degrees of freedom of three-dimensional movements is described. The main advantages of this goniometer linkage system are ease of handling and good cost-quality relationship. For small movements it has an accuracy of about 0.1 mm and 0.1 degree. Six potentiometers are rod-linked in such a way that the system can follow any movement, unconstrained. From the rotation of the potentiometers, the spatial movement of two solid bodies can be calculated by a computer. The reliability of the system has been demonstrated in several in vitro and in vivo applications.