7 236 817

7,236,817 Title:

Animation technology

A method for creating an animated image of the bones of a body part is described. The steps include converting Computed Axial Tomography (CAT or CT) scan and Magnetic Resonance Imaging (MRI) 2-dimensional cross-sectional images (slices) into 3-dimensional images of individual bones (FIG. 1). A first ordered series of slices of a body part in a first position is converted into a 3-dimensional representation of the skeleton of the body part and then a second ordered series of slices of the same body part in a different position is converted. The converted images are then used to create a step frame animation of the movement of the skeleton of the body part. Additional ordered series of slices of the body part in other intermediate positions could be used in the step frame animation. The steps of the method may also include the process of separating the bones if they are depicted as co-joined in a slice (FIGS. 6 and 7). The method can also include the identification of isometric points (FIGS. 8 to 11) on the separated bones to aid a clinician in the diagnosis of a problem or abnormality as well as assist in the application of "what if" surgical procedures on the digital representation of the skeleton of the scanned body part. The method can also include steps that create movement of the bones of the body part by applying rules of motion for one or more points on the separated bones of the scanned body part.

The claims defining the invention are as follows:

1. A method of producing 3-dimensional visualisations of digital representations of cross-sectional slices of a vertebrate animal or human bodypart includes the steps of: a) obtaining a first ordered series of slices of a portion of said body part in a first position; b) applying one or more filters to each of said digital representations of said first ordered series of slices to identify theskeletal portions of said body part; c) converting said first filtered series into a 3-dimensional representation of the skeleton of said body part in said first position; d) obtaining a second ordered series of slices of said portion of said body partin a second position different to said first position wherein said first and said second position of said portion of said body part is representative of extremes of the achievable movement of said portion of said body part; e) applying one or morefilters to each of said digital representations of said second ordered series of slices to identify the skeletal portions of said body part; f) converting said second filtered series into a 3-dimensional representation of the skeleton of said body partin said second position; g) combining said 3-dimensional representations to form a step frame animation having as many steps as there are ordered series of slices.

2. A method according to claim 1 further includes the further steps of: h) obtaining a one or more further ordered series of slices of said portion of said body part in a one or more further positions between the extremes of the achievablemovement; i) converting said further filtered series into a 3-dimensional representation of the skeleton of said body part in said further positions; j) combining said 3-dimensional representations to form a step frame animation having as many steps asthere are ordered series of slices.

3. A method according to claim 1 further includes the steps of: k) selecting a plurality of points on two or more skeletal object s in each said 3-dimensional representation; and l) analysing whether the distance between pairs of said pointson different skeletal objects are isometric, if the distance between pairs of points remain the same or within a predetermined variance of distance during said step frame animation.

4. A method according to claim 3 further includes the step of: m) comparing the changes, if any, of the distances between predetermined pairs of points with expected changes, wherein the result of said comparison provides assistance to acliniclan to form a diagnosis regarding the body part.

5. A method according to claim 3 wherein isometric points determined equate substantially to the fixation location of the ends of ligaments associated with said portion of said body part and the further step of: n) comparing the isometricpoints determined in step 3 to predetermined isometric points of a typical or contra-lateral body part and if said isometric points vary a greater than a predetermined amount a problem or abnormality or a degree of problem or abnormality associated withone or more ligaments associated with said portion of said body part exists.

6. A method according to claim 1 wherein step b and/or e includes a filter that allows an anatomically knowledgeable medical professional to adjust the bone selection criteria of said filter until a representation of adjacent bones shows thatsaid adjacent bones are separate from one another.

7. A method according to claim 6 wherein said filter that allows an anatomically knowledgeable medical professional to adjust the density range criteria of said filter until a representation of adjacent bones shows that said adjacent bones areseparate from one another.

8. A method according to claim 1 wherein said digital representation of slices of a vertebrate animal or human body part is provided by CAT/CT or MRI apparatus.

9. A method of producing 3-dimensional visualisations of digital representations of cross-sectional slices of a vertebrate animal or human body part includes the steps of: a) obtaining a first ordered series of slices of a portion of said bodypart in a first position; b) applying one or more filters to each of said digital representations of said first ordered series of slices to identify the skeletal portions of said body part; c) converting said first filtered series into a 3-dimensionalrepresentation of the skeleton of said body part in said first position; d) obtaining a second ordered series of slices of said portion of said body part in a second position wherein said first and said second position of said portion of said body partis representative of extremes of the achievable movement of said portion of said body part; e) applying one or more filters to each of said digital representations of said second ordered series of slices to identify the skeletal portions of said bodypart; f) converting said second filtered series into a 3-dimensional representation of the skeleton of said body part in said second position; g) applying to one or more points on the skeleton of said body part of each said 3-dimensionalrepresentation, one or more rules based animation constraints; h) creating a 3-dimensional animation of the movement of said body part according to said constraints.

10. A method according to claim 9 further includes the further steps of: i) obtaining a one or more further ordered series of slices of said portion of said body part in a one or more further positions between the extremes of the achievablemovement; j) converting said further filtered series into a 3-dimensional representation of the skeleton of said body part in said further positions; k) combining said 3-dimensional representations to form a step frame animation having as many steps asthere are ordered series of slices according to said rules based animation constraints.

11. A method according to claim 9, wherein step b and/or e of claim 10 includes a filter that allows an anatomically knowledgeable medical professional to adjust the bone selection criteria of said filter until a representation of adjacentbones shows that said adjacent bones are separate from one another.

12. A method according to claim 9, wherein said digital representation of slices of a vertebrate animal or human body part is provided by CAT/CT or MRI apparatus.