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Application of 3SPACE™ ISOTRAK™ to joint kinematic study
912
Abstracts
AN INSTRUMENTED GRACE FOR STUDY OF LEGG-CALVE-PERTHES DISEASE H. I. Abou Ghaida*. H. L. Hull*. and 6. T. Rabf Departments of Mechanical Engineering* and Orthopedic Surgery? University of California, Davis. CA 95616 The accepted clinical method for treating children with Legg-Calve-Perthes disease is by means of abduction bracing. To evaluate the effectiveness of this method, one major necessary step is solving the three-dimensional inverse dynamics Problem for the intersegmental loads at the hip joint. In order to provide part of the external loading data on the lower limb required to solve this problem, an instrumented abduction brace has been designed. The instrumented brace duplicates the mechanical behavior of the Scottish Rite Atlanta treatment brace, currently a clinically popular device. Instrumentation of the actual Atlanta brace was not considered, since its complicated mechanism couples forces applied by the brace to the thighs, resulting in moments difficult to measure. The new design eliminates all moments and simply applies one single force to the center of the femur. This single force is measured by a strain gage dynamometer. 70 assess the utility of the instrumented brace, the brace was fitted to three test subjects and the brace force was recorded while children walked through multiple trials. The mechanical design of the brace not only enables the brace to readily fit the subjects, but also enables gait similar to that of the Atlanta brace. Further, force measurements show a large lateral component thus justifying the need for instrumenting the brace. Testing of the brace demonstrates that it can be considered a dependable tool in studying the mechanical interactions between the brace and patient.
PERFORMANCEANALYSIS OF THE DYNAMIC
PROGRAHHINGDIFFERENTIATING
Zvi Ladin and JeEE Sable Biomedical Engineering Department and NeuroHuscular Boston University, Boston, HA 02215
Research
ALGORITHM
Center
The wide use of optoelectronic position measurement systems to monitor human accurate and efficient East, for need the movement has focused differentiating/filtering algorithms. Synchronous measurements of position and of a known kinematics across a frequency band of l-llHz, and an acceleration analysis aimed at extracting the main features of the acceleration signal enabled to compare pantitatively different differentiating algorithms. This paper us tests the performance of the Dynamic Programming (DP) differentiator and compares the Lagrange/Butterworth (LB) differentiator and to the raw accelerosoter it to the DP differentiator has good that Preliminary results suggest readings. and that its cut-off frequency is detormincd by low-pass filtering characeristics, the numerical value of its weighting parameter.
APPLICATION OF 3SPACE" ISOTRAK" TO JOINT KINEMATIC STUDY Kai-Nan An, Myron C. Jacobsen, James Kouba, Lawrence Berglund, 6. Patrick Cahill, Edmund Y.S. Chao Orthopedic Biomechanics Laboratory, Mayo Clinic/Mayo Foundation Rochester, Minnesota 55905 U.S.A. The 3SPACE'" ISOTRAK" system is a commercially available device for the determination of the position and orientation of sensor in relation to a source by utilizing the principle of low-frequency, magnetic field technoloqy. The application of such a system to the biomechanical study of human movement is examined' in this study. Both-studies of planar particle motion and spatial t-iaid body motion based on the Eulerian anale descriotion and screw axis displacement have been performed. The system is found to be quite accurate and easy to use, which should be a useful tool in kinesiologic research.
Abstracts
AN INSTRUMENTED GRACE FOR STUDY OF LEGG-CALVE-PERTHES DISEASE H. I. Abou Ghaida*. H. L. Hull*. and 6. T. Rabf Departments of Mechanical Engineering* and Orthopedic Surgery? University of California, Davis. CA 95616 The accepted clinical method for treating children with Legg-Calve-Perthes disease is by means of abduction bracing. To evaluate the effectiveness of this method, one major necessary step is solving the three-dimensional inverse dynamics Problem for the intersegmental loads at the hip joint. In order to provide part of the external loading data on the lower limb required to solve this problem, an instrumented abduction brace has been designed. The instrumented brace duplicates the mechanical behavior of the Scottish Rite Atlanta treatment brace, currently a clinically popular device. Instrumentation of the actual Atlanta brace was not considered, since its complicated mechanism couples forces applied by the brace to the thighs, resulting in moments difficult to measure. The new design eliminates all moments and simply applies one single force to the center of the femur. This single force is measured by a strain gage dynamometer. 70 assess the utility of the instrumented brace, the brace was fitted to three test subjects and the brace force was recorded while children walked through multiple trials. The mechanical design of the brace not only enables the brace to readily fit the subjects, but also enables gait similar to that of the Atlanta brace. Further, force measurements show a large lateral component thus justifying the need for instrumenting the brace. Testing of the brace demonstrates that it can be considered a dependable tool in studying the mechanical interactions between the brace and patient.
PERFORMANCEANALYSIS OF THE DYNAMIC
PROGRAHHINGDIFFERENTIATING
Zvi Ladin and JeEE Sable Biomedical Engineering Department and NeuroHuscular Boston University, Boston, HA 02215
Research
ALGORITHM
Center
The wide use of optoelectronic position measurement systems to monitor human accurate and efficient East, for need the movement has focused differentiating/filtering algorithms. Synchronous measurements of position and of a known kinematics across a frequency band of l-llHz, and an acceleration analysis aimed at extracting the main features of the acceleration signal enabled to compare pantitatively different differentiating algorithms. This paper us tests the performance of the Dynamic Programming (DP) differentiator and compares the Lagrange/Butterworth (LB) differentiator and to the raw accelerosoter it to the DP differentiator has good that Preliminary results suggest readings. and that its cut-off frequency is detormincd by low-pass filtering characeristics, the numerical value of its weighting parameter.
APPLICATION OF 3SPACE" ISOTRAK" TO JOINT KINEMATIC STUDY Kai-Nan An, Myron C. Jacobsen, James Kouba, Lawrence Berglund, 6. Patrick Cahill, Edmund Y.S. Chao Orthopedic Biomechanics Laboratory, Mayo Clinic/Mayo Foundation Rochester, Minnesota 55905 U.S.A. The 3SPACE'" ISOTRAK" system is a commercially available device for the determination of the position and orientation of sensor in relation to a source by utilizing the principle of low-frequency, magnetic field technoloqy. The application of such a system to the biomechanical study of human movement is examined' in this study. Both-studies of planar particle motion and spatial t-iaid body motion based on the Eulerian anale descriotion and screw axis displacement have been performed. The system is found to be quite accurate and easy to use, which should be a useful tool in kinesiologic research.