Method for registering articulated anatomical structures

Patent metadata

Field	Value
Publication number	US-11172995-B2
Application number	US-202016854272-A
Country	US
Kind code	B2
Filing date	Apr 21, 2020
Priority date	May 29, 2015
Publication date	Nov 16, 2021
Grant date	Nov 16, 2021

Abstract

The present invention relates to a method for registering a first anatomical structure (1) which is articulately coupled to a second anatomical structure (2), the method being constituted to be executed by a computer and comprising the steps of:acquiring second structure correlation data describing the spatial position of at least one correlation feature (3) relative to the second anatomical structure (2);acquiring coupling data describing a positional fixation (6) of the first anatomical structure (1) relative to the second anatomical structure (2), which is set by the articulated coupling (4) between the first anatomical structure (1) and the second anatomical structure (2);determining, based on the second structure correlation data and the coupling data, first structure correlation data describing the spatial position of the at least one correlation feature (3) relative to the first anatomical structure (1).The present invention further relates to a corresponding computer program and system.

First claim

The invention claimed is:

1. A computer-implemented method for registering articulated anatomical structures, the method comprising:
obtaining at least one image and first structure correlation data, wherein the first structure correlation data describes a first spatial position of at least one correlation feature relative to a second spatial position of at least one geometrical feature of a first anatomical structure articulately coupled to a second anatomical structure, wherein the at least one image comprises one or more of the first anatomical structure or the second anatomical structure, wherein the first anatomical structure comprises a femur, the second anatomical structure comprises a pelvis, the at least one correlation feature comprises a midsagittal plane, and the at least one geometrical feature comprises a mechanical axis of the femur;
generating coupling data describing a positional fixation of the second anatomical structure relative to the first anatomical structure, wherein the positional fixation is established by the articulated coupling between the first anatomical structure and the second anatomical structure, wherein a position or a positional relationship of the positional fixation, the at least one geometrical feature, the at least one correlation feature, or at least one reference feature is determined based on the at least one image, wherein the at least one reference feature comprises an anatomical landmark of the pelvis comprising an anterior superior iliac spine or a most lateral point of a iliac crest and the positional fixation comprises a centre of rotation of a hip joint;
determining, based on the first structure correlation data and the coupling data, second structure correlation data to facilitate registration of the second anatomical structure, wherein the second structure correlation data describes the first spatial position of the at least one correlation feature relative to the second anatomical structure, wherein the relative position between the at least one reference feature and the positional fixation is invariant in a first coordinate system positionally assigned to the second anatomical structure and a second coordinate system positionally assigned to the first anatomical structure; and
generating and outputting surgical guidance information to an indicating device based on the registration of the second anatomical structure.

2. The computer-implemented method according to claim 1 , wherein the at least one image is an X-ray image taken in an anterior-posterior direction and the position or positional relationship of one or more of the positional fixation, the at least one correlation feature, or the at least one reference feature is determined via one or more of angular or distance measurements within the at least one image.

3. The computer-implemented method according to claim 1 , wherein the midsagittal plane is defined within the second coordinate system as being parallel to the mechanical axis of the femur, running through the centre of rotation of the hip joint, and as being spaced from the mechanical axis of the femur in a medial direction by a distance between the centre of rotation of the hip joint and the midsagittal plane within the first coordinate system.

4. The computer-implemented method according to claim 1 , wherein the second spatial position of the at least one correlation feature relative to the second anatomical structure is determined based on establishing within the second coordinate system a third spatial position of the at least one reference feature relative to the positional fixation.

5. The computer-implemented method according to claim 1 , further comprising determining a third spatial position of the anatomical landmark of the pelvis, and obtaining anatomical data of the pelvis from one or more of an anatomical atlas or one or more additional images taken from different directions, to facilitate definition of a functional coronal pelvis plane.

6. The computer-implemented method according to claim 1 , further comprising virtually rotating the femur together with the second coordinate system around the centre of rotation of the hip joint to achieve an alignment of the second coordinate system with the first coordinate system.

7. The computer-implemented method according to claim 1 , wherein the second coordinate system is defined to have a y-axis parallel to the mechanical axis of the femur and an x-axis perpendicular to the y-axis and parallel to a medial-lateral direction with respect to the femur.

8. The computer-implemented method according to claim 1 , further comprising measuring in a medial-lateral direction a distance of the at least one reference feature and the centre of rotation of the hip joint relative to the midsagittal plane, or determining an angle within a plane of the image defined by the midsagittal plane and a straight comprising the at least one reference feature and the centre of rotation of the hip joint, to determine the relative position between the at least one reference feature and the positional fixation.

9. A computing device, comprising memory comprising programmed instructions stored thereon for registering articulated anatomical structures and one or more processors coupled to the memory and configured to execute the stored programmed instructions to:
obtain at least one image and first structure correlation data, wherein the first structure correlation data describes a first spatial position of at least one correlation feature relative to a second spatial position of at least one geometrical feature of a first anatomical structure articulately coupled to a second anatomical structure, wherein the at least one image comprises one or more of the first anatomical structure or the second anatomical structure, wherein the first anatomical structure comprises a femur, the second anatomical structure comprises a pelvis, the at least one correlation feature comprises a midsagittal plane, and the at least one geometrical feature comprises a mechanical axis of the femur;
generate coupling data describing a positional fixation of the second anatomical structure relative to the first anatomical structure, wherein the positional fixation is established by the articulated coupling between the first anatomical structure and the second anatomical structure, wherein a position or a positional relationship of the positional fixation, the at least one geometrical feature, the at least one correlation feature, or at least one reference feature is determined based on the at least one image, wherein the at least one reference feature comprises an anatomical landmark of the pelvis comprising an anterior superior iliac spine or a most lateral point of a iliac crest and the positional fixation comprises a centre of rotation of a hip joint;
determine, based on the first structure correlation data and the coupling data, second structure correlation data to facilitate registration of the second anatomical structure, wherein the second structure correlation data describes the first spatial position of the at least one correlation feature relative to the second anatomical structure, wherein the relative position between the at least one reference feature and the positional fixation is invariant in a first coordinate system positionally assigned to the second anatomical structure and a second coordinate system positionally assigned to the first anatomical structure; and
generate and output surgical guidance information to an indicating device based on the registration of the second anatomical structure.

10. The computing device of claim 9 , wherein the at least one image is an X-ray image taken in an anterior-posterior direction and the position or positional

Assignees

• Smith & Nephew Inc
• Smith & Nephew Asia Pacific Pte Ltd
• Smith & Nephew Orthopaedics Ag
• Smith & Newphew Orthopaedics Ag

Inventors

• Dohmen Lars
• Schubert Mario
• Wiedenmann Anna

Classifications

• A61B34/10

  Computer-aided planning, simulation or modelling of surgical operations · CPC title

• G06T7/74

  involving reference images or patches · CPC title

• A61B2090/376

  using X-rays, e.g. fluoroscopy · CPC title

• A61B2034/2065

  Tracking using image or pattern recognition · CPC title

• G06T7/73

  using feature-based methods · CPC title