Biomedical subjects
Publications and source records attributed to E K Antonsson.
We address amplification of noise in double differentiation of position histories for dynamic analysis of gait. Measurements of the frequency domain characteristics of signal and noise are required to quantitatively assess errors in raw, filtered, and dynamic gait data. The results of a simple technique to determine the frequency content of gait using a population of 12 subjects and a total of 30 gait records is presented.
A fully automatic optoelectronic photogrammetric technique is presented for measuring the spatial kinematics of human motion (both position and orientation) and estimating the inertial (net) dynamics. Calibration and verification showed that in a two-meter cube viewing volume, the system achieves one millimeter of accuracy and resolution in translation and 20 milliradians in rotation. Since double differentiation of generalized position data to determine accelerations amplifies noise, the frequency domain characteristics of the system were investigated. It was found that the noise and all other errors in the kinematic data contribute less than five percent error to the resulting dynamics.