Patent ID: 6415043
Filing Date: 2002-07-02
Classification: A61B,G06T

Abstract:
A method for determining X, Y and Z-axis coordinates of a marker comprising:placing said marker having a predetermined dimension on a body; providing a camera including an optical element and an optical sensing device having a center point, said camera being adapted for projecting an image of said marker onto said optical sensing device, wherein a distance between said optical element and said optical sensing device is known; projecting the image of said marker onto said optical sensing device; determining the center point of said projected image relative to the center point of said optical sensing device, the center point of said projected image including both X and Y-axis coordinates relative to the center point of said optical sensing device; determining a dimension parameter of the image projected onto said optical sensing device; and using the predetermined dimension parameter of said marker, the determined dimension parameter of said projected image, the determined center point of said projected image, and the known distance between said optical element and said optical sensing device to determine the X, Y, and Z-axis coordinates of said marker.