Interpolation in transform space for multiple rigid object registration

A method of mapping surgical tools in real space to a warped image space, the method comprising:

• (a) obtaining a diagnostic medical image of a subject including multiple rigid objects, the medical image having has at least one deformed region;
• (b) individually computing separate transforms which register each of the rigid objects in real space with their corresponding locations in the warped image space, the transforms accounting for the at least one deformation;
• (c) positioning a surgical tool in real space;
• (d) mapping target points which define the surgical tool in real space to the warped image space using the transforms to map the surgical tool into the warped image space;
• and,
• (e) displaying an image representation of the surgical tool in the warped image space, such that the image representation of the surgical tool in the warped image space appears deformed in relation to the surgical tool in real space.

An image guided surgery system comprising:

• a support on which a subject is positioned in real space;
• a human viewable display on which is rendered, in an image space, an image representation of anatomy of the subject, said anatomy including a plurality of rigid objects;
• a surgical tool having points thereon from which radiant energy is directed;
• a detector unit which tracks an orientation and position of the surgical tool in real space via the radiant energy directed therefrom;
• and,
• a processor which maps the orientation and position of the surgical tool from real space into image space using an interpolated transform, said interpolated transform being interpolated from a number of rigid object transforms which each register one of the plurality of rigid objects in real space to its corresponding image in image space.

An image guided surgery system comprising:

• an area in which a subject is positioned in real space;
• a surgical tool having points thereon from which radiant energy is directed;
• a detector unit which tracks the surgical tool in real space via the radiant energy directed therefrom;
• a processor which maps the surgical tool from real space into at least a warped portion of image space using a plurality of spatial mapping transforms, the transforms accounting for a warping of the warped portion of the image space, said transforms each registering one of a plurality of rigid objects in real space the warped portioned of image space;
• and,
• a human viewable display on which is rendered, in image space, an image representation of anatomy of the subject and an image representation of the surgical tool, wherein, as visualized on the human viewable display, the surgical tool is deformed in the warped portion of image space to compensate for differences in relative spatial positioning between the rigid objects in real space as compared to the warped region of image space.

A method of mapping a chosen point in real space to a corresponding location in image space, the method comprising:

• (a) obtaining a diagnostic medical image of a subject including multiple rigid objects;
• (b) individually computing separate transforms which register each of the rigid objects in real space with their corresponding locations in image space;
• (c) choosing a target point in real space;
• (d) selecting a number of the rigid objects which are closest to the target point;
• (e) generating an interpolated transform from the separate transforms which correspond to the selected rigid objects;
• and,
• (f) mapping the target point in image space using the interpolated transform without spatially transforming the diagnostic medical image.