University of Worcester Worcester Research and Publications
 
  USER PANEL:
  ABOUT THE COLLECTION:
  CONTACT DETAILS:

Eccentric Elliptical Contours in Total Hip Replacements

Kerrigan, Stuart and McKenna, S.J. and Ricketts, I.W. and Wigderowitz, C.A. (2004) Eccentric Elliptical Contours in Total Hip Replacements. In: Proceedings of the Eighth Annual Medical Image Understanding and Analysis Conference. The British Machine Vision Association, Durham, pp. 216-219. ISBN 1 901725 27 8

[img] Text
paper4.pdf
Restricted to Repository staff only

Download (936kB) | Request a copy

Abstract

The active ellipses method for assessing wear in total hip replacements uses robust ellipse fitting to localise the contours of the femoral head and acetabular rim wire marker. In the case of the latter these ellipses can be very eccentric and the standard algebraic distance was shown to be inadequate. The geometric distance from an ellipse to a point is not trivial to compute and thus numerous error of fit functions have been created. In this work several of these error of fit functions are compared, including a geometric error of fit function, on both synthetic data and by using active ellipses on a set of test radiographs containing eccentric rims. Least squares estimation using a geometric error function was most accurate in the presence of Gaussian noise. However, least median of squares estimation using a geometric error function was most accurate in the presence of outliers. Furthermore, its performance was similar to that of a computationally cheaper error function known as the foci bisector distance to the extent that the two were almost interchangeable.

Item Type: Book Section
Additional Information:

The full-text can be accessed via the official URL.

Uncontrolled Keywords: active ellipses, total hip replacements, assessing wear, ellipse fitting, fitting algorithms
Subjects: Q Science > QA Mathematics > QA76 Computer software
Divisions: Academic Departments > Worcester Business School
Related URLs:
Depositing User: Stuart Kerrigan
Date Deposited: 06 Jul 2017 11:21
Last Modified: 11 Jul 2017 12:45
URI: https://eprints.worc.ac.uk/id/eprint/5649

Actions (login required)

View Item View Item
 
     
Worcester Research and Publications is powered by EPrints 3 which is developed by the School of Electronics and Computer Science at the University of Southampton. More information and software credits.