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US 8,771,188 B2Granted
Ultrasonic bone motion tracking system
AssigneePerception Raisonnement Action en Medecine
InventorsJonathan Schers, Christopher Plaskos, Stephane Lavallee, Jocelyne Troccaz
Life of this patent
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Abstract
A computerized bone motion tracking system according to one exemplary embodiment is configured to: provide a non-invasive means for accurate measurement and tracking of the motion of a bone using a volumetric ultrasound transducer and a three dimensional position measurement system; provide relative measurements of one bone relative to another bone of a joint; decompose relative joint motion into specific components; and measure joint instability and range of motion.
Claims21
A method for non-invasively tracking a bone of a subject in three-dimensional space, the method comprising:
- (a) attaching a 3D or 4D volumetric ultrasound imaging transducer to the subject and acquiring a first reference image volume I0 of a bone surface with the 3D or 4D volumetric ultrasound imaging transducer at an initial time t0, wherein the 3D or 4D volumetric ultrasound imaging transducer acquires 3D image pixel volumes;
- (b) determining an initial position of the bone using the first reference image volume I0;
- (c) acquiring a second image volume I1 of the bone surface with the 3D or 4D volumetric ultrasound imaging transducer at a second time t1;
- (d) measuring a three-dimensional position of the 3D or 4D volumetric ultrasound imaging transducer with a three-dimensional position measuring device at the times t0 and t1 and associating each position with the corresponding image volumes I0 and I1;
- (e) searching for a relative position of I0 and I1 for which overlapping portions of the image volumes of I0 and I1 are closest aligned to one another and defining this position as a best-match position;
- (f) determining a 3D transformation between the first reference image volume and the second image volume that corresponds to the best-match position;
- and
- (g) repeating steps c to f.
5 more elements
A method for non-invasively tracking a bone of a subject in three-dimensional space, the method comprising:
- attaching a 3D or 4D volumetric ultrasound imaging transducer to the subject and acquiring a first reference image volume I0 of a bone surface with the 3D or 4D volumetric ultrasound imaging transducer at an initial time t0, wherein the 3D or 4D volumetric ultrasound imaging transducer acquires 3D image pixel volumes, and wherein the first reference image volume I0 has a first coordinate system;
- determining an initial position of the bone using the first reference image volume I0;
- acquiring a second image volume I1 of the bone surface with the 3D or 4D volumetric ultrasound imaging transducer at a second time t1;
- measuring a three-dimensional position of the 3D or 4D volumetric ultrasound imaging transducer with a three-dimensional position measuring device at the times t0 and t1 and associating each position with the corresponding image volumes I0 and I1;
- searching for a relative position of I0 and I1 for which overlapping portions of the image volumes of I0 and I1 are closest aligned to one another and defining this position as a best-match position;
- and
- determining a 3D transformation between the first reference image volume and the second image volume that corresponds to the best-match position, wherein the second image volume I1 is displaced from the first coordinate system in the best-match position.
4 more elements
A method for non-invasively tracking a bone of a subject in three-dimensional space, the method comprising:
- (a) acquiring a position coordinate system at initial time t0 using a three-dimensional position measuring device;
- (b) attaching a 3D or 4D volumetric ultrasound imaging transducer to the subject and acquiring a first reference image volume I0 of the bone and tissue adjacent to and attached to the bone with the 3D or 4D volumetric ultrasound imaging transducer at initial time t0 while simultaneously tracking the 3D or 4D volumetric ultrasound imaging transducer;
- (c) determining an initial position of the bone using the first reference image volume I0 and the position coordinate system;
- (d) acquiring a second image volume I1 of the bone with the 3D or 4D volumetric ultrasound imaging transducer at a second time t1 while simultaneously tracking the 3D or 4D volumetric ultrasound imaging transducer;
- (e) selecting a region of interest corresponding to a subset of the first reference image volume I0 and the second image volume I1;
- (f) searching for a relative position of I0 and I1 for the selected region of interest for which overlapping portions of the image volumes of I0 and I1 are closest aligned to one another and defining this position as a best-match position;
- (g) determining a 3D transformation between the first reference image volume and the second image volume that corresponds to the best-match position;
- and
- (h) repeating steps (d) to (g).
6 more elements
Dependencies are inferred from the claim text.