Resumen
The direct current electromagnetic tracking device has seen increasing use in biomechanics studies of joint kinematics and anatomical surface geometry. In these applications, a stylus is attached to a sensor to measure the spatial location of three-dimensional landmarks. Stylus calibration is performed by rotating the stylus about a fixed point in space and using regression analysis to determine the tip offset vector. Measurement errors can be induced via several pathways, including; intrinsic system errors in sensor position or angle and tip offset calibration errors. A detailed study was performed to determine the errors introduced in digitizing small surfaces with different stylus lengths (35, 55, and 65 mm) and approach angles (30 and 45 degrees) using a plastic calibration board and hemispherical models. Two-point discrimination errors increased to an average of 1.93 mm for a 254 mm step size. Rotation about a single point produced mean errors of 0.44 to 1.18 mm. Statistically significant differences in error were observed with increasing approach angles (p < 0.001). Errors of less than 6% were observed in determining the curvature of a 19 mm hemisphere. This study demonstrates that the 'Flock of Birds' can be used as a digitizing tool with accuracy better than 0.76% over 254 mm step sizes.
Idioma original | English |
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Páginas (desde-hasta) | 23-28 |
Número de páginas | 6 |
Publicación | Biomedical Sciences Instrumentation |
Volumen | 35 |
Estado | Published - 1999 |
Evento | Proceedings of the 1999 36th Annual Rocky Mountain Bioengineering Symposium (RMBS) and 36th International ISA Biomedical Sciences Instrumentation Symposium - Copper Mountain, CO, USA Duración: abr. 16 1998 → abr. 18 1998 |
ASJC Scopus Subject Areas
- Biophysics
- Medical Laboratory Technology